经济学原理-曼昆课后答案-chapter-4Word版
曼昆经济学原理-习题答案
曼昆经济学原理-习题答案第一篇导言第一章经济学十大原理1(列举三个你在生活中面临的重要权衡取合的例子。
答:?大学毕业后(面临着是否继续深造的选择，选择继续上学攻读研究生学位，就意味着在今后三年中放弃参加工作、赚工资和积累社会经验的机会;2、在学习为什么各国之间的贸易不像竞赛一样有赢家和输家呢?答:因为贸易使各国可以专门从事自己最擅长的话动，并从中享有更多的各种各样的物品与劳务。
通过贸易使每个国家可供消费的物质财富增加，经济状况变得更好。
因此，各个贸易国之间既是竞争对手，又是经济合作伙伴。
在公平的贸易中是“双赢”或者“多赢”的结果。
6(市场巾的那只“看不见的手”在做什么呢，答:市场中那只“看不见的手”就是商品价格，价格反映商品自身的价值和社会成本，市场中的企业和家庭在作出买卖决策时都要关注价格。
因此(他们也会不自觉地考虑自己行为的(社会)收益和成本。
从而，这只“看不见的手”指引着干百万个体决策者在大多数情况下使社会福利趋向最大化。
7 解释市场失灵的两个主要原因，并各举出一个例子。
答:市场失灵的主要原因是外部性和市场势力。
外部性是一个人的行为对旁观者棉利的影响。
当一个人小完全承担(或享受)他的行为所造成的成本(或收益)时，就会产生外部性。
举例:如果一个人不承担他在公共场所吸烟的全部成本，他就会毫无顾忌地吸烟。
在这种情况下，政府可以通过制定禁止在公共场所吸烟的规章制度来增加经济福利。
市场势力是指一个人(或一小群人)不适当地影响市场价格的能力。
例如:某种商品的垄断生产者由于几乎不受市场竞争的影响，可以向消费者收取过高的垄断价格。
在这种情况下，规定垄断者收取的价格有可能提高经济效率。
8(为什么生产率是重要的?答:因为一国的生活水平取决于它生产物品与劳务的能力，而对这种能力的最重要的衡量度就是生产率。
生产率越高，一国生产的物品与劳务量就越多。
9什么是通货膨胀，什么引起了通货膨胀?答:通货膨胀是流通中货币量的增加而造成的货币贬值生活中价格总水平上升。
经济学原理曼昆课后答案chapter4
经济学原理曼昆课后答案c h a p t e r4本页仅作为文档封面，使用时可以删除This document is for reference only-rar21year.MarchProblems and Applications1. a. Cold weather damages the orange crop, reducing the supply of oranges.This can be seen in Figure 4-6 as a shift to the left in the supply curve fororanges. The new equilibrium price is higher than the old equilibriumprice.Figure 4-6b. People often travel to the Caribbean from New England to escape coldweather, so demand for Caribbean hotel rooms is high in the winter. Inthe summer, fewer people travel to the Caribbean, since northern climesare more pleasant. The result, as shown in Figure 4-7, is a shift to the leftin the demand curve. The equilibrium price of Caribbean hotel rooms isthus lower in the summer than in the winter, as the figure shows.Figure 4-7c. When a war breaks out in the Middle East, many markets are affected.Since much oil production takes place there, the war disrupts oil supplies, shifting the supply curve for gasoline to the left, as shown in Figure 4-8.The result is a rise in the equilibrium price of gasoline. With a higherprice for gasoline, the cost of operating a gas-guzzling automobile, like aCadillac, will increase. As a result, the demand for used Cadillacs willdecline, as people in the market for cars won't find Cadillacs as attractive.In addition, some people who already own Cadillacs will try to sell them.The result is that the demand curve for used Cadillacs shifts to the left,while the supply curve shifts to the right, as shown in Figure 4-9. Theresult is a decline in the equilibrium price of used Cadillacs.Figure 4-8Figure 4-92. The statement that "an increase in the demand for notebooks raises the quantityof notebooks demanded, but not the quantity supplied" is false, in general. AsFigure 4-10 shows, the increase in demand for notebooks results in an increased quantity supplied. The only way the statement would be true is if the supplycurve were perfectly inelastic, as shown in Figure 4-11.Figure 4-10Figure 4-113. a. If people decide to have more children (a change in tastes), they'll wantlarger vehicles for hauling their kids around, so the demand for minivanswill increase. Supply won't be affected. The result is a rise in both priceand quantity, as Figure 4-12 shows.Figure 4-12Figure 4-13b. If a strike by steelworkers raises steel prices, the costs of producing aminivan rise (a rise in input prices), so the supply of minivans decreases.Demand won't be affected. The result is a rise in the price of minivansand a decline in the quantity, as Figure 4-13 shows.c. The development of new automated machinery for the production ofminivans is an improvement in technology. The reduction in firms' costsresults in an increase in supply. Demand isn't affected. The result is a decline in the price of minivans and an increase in the quantity, as Figure 4-14shows.Figure 4-14Figure 4-15d. The rise in the price of station wagons affects minivan demand becausestation wagons are substitutes for minivans (that is, there's a rise in theprice of a related good). The result is an increase in demand for minivans.Supply isn't affected. In equilibrium, the price and quantity of minivansboth rise, as Figure 4-12 shows.e. The reduction in peoples' wealth caused by a stock-market crash reducestheir income, leading to a reduction in the demand for minivans, sinceminivans are a normal good. Supply isn’t affected. As a result, both priceand quantity decline, as Figure 4-15 shows.4. Technological advances that reduce the cost of producing computer chipsrepresent a decline in an input price for producing a computer. The result is ashift to the right in the supply of computers, as shown in Figure 4-16. Theequilibrium price falls and the equilibrium quantity rises, as the figure shows.Figure 4-16Figure 4-17Since computer software is a complement to computers, the increasedequilibriumquantity of computers increases the demand for software. As Figure 4-17 shows, the result is a rise in both the equilibrium price and quantity of software.Since typewriters are substitutes for computers, the increased equilibriumquantity of computers reduces the demand for typewriters. As Figure 4-18shows, the result is a decline in both the equilibrium price and quantity oftypewriters.Figure 4-185. a. When a hurricane in South Carolina damages the cotton crop, it raisesinput prices for producing sweatshirts. As a result, the supply ofsweatshirts shifts to the left, as shown in Figure 4-19. The newequilibrium has a higher price and lower quantity of sweatshirts.b. A decline in the price of leather jackets leads more people to buy leatherjackets, reducing the demand for sweatshirts. The result, shown in Figure 4-20, is a decline in both the equilibrium price and quantity of sweatshirts.Figure 4-20c. The effects of colleges requiring students to engage in morningcalisthenics in appropriate attire raises the demand for sweatshirts, asshown in Figure 4-21. The result is an increase in both the equilibriumprice and quantity of sweatshirts.d. The invention of new knitting machines increases the supply ofsweatshirts. As Figure 4-22 shows, the result is a reduction in theequilibrium price and an increase in the equilibrium quantity ofsweatshirts.Figure 4-226. A temporarily high birth rate in the year 2005 leads to opposite effects on theprice of babysitting services in the years 2010 and 2020. In the year 2010, there are more 5-year olds who need sitters, so the demand for babysitting servicesrises, as shown in Figure 4-23. The result is a higher price for babysitting services in 2010. However, in the year 2020, the increased number of 15-year olds shifts the supply of babysitting services to the right, as shown in Figure 4-24. Theresult is a decline in the price of babysitting services.Figure 4-23Figure 4-247. Since ketchup is a complement for hot dogs, when the price of hot dogs rises,the quantity demanded of hot dogs falls, thus reducing the demand for ketchup, causing both price and quantity of ketchup to fall. Since the quantity of ketchup falls, the demand for tomatoes by ketchup producers falls, so both price andquantity of tomatoes fall. When the price of tomatoes falls, producers of tomato juice face lower input prices, so the supply curve for tomato juice shifts down,causing the price of tomato juice to fall and the quantity of tomato juice to rise.The fall in the price of tomato juice causes people to substitute tomato juice for orange juice, so the demand for orange juice declines, causing the price andquantity of orange juice to fall. Now you can see clearly why a rise in the price ofhot dogs leads to a fall in price of orange juice!Figure 4-258. a. Cigars and chewing tobacco are substitutes for cigarettes, since a higherprice for cigarettes would increase demand for cigars and chewingtobacco.b. An increase in the tax on cigarettes leads to increased demand for cigarsand chewing tobacco. The result, as shown in Figure 4-25 for cigars, is arise in both the equilibrium price and quantity of cigars and chewingtobacco.c. The results in part (b) showed that a tax on cigarettes leads people tosubstitute cigars and chewing tobacco for cigarettes when the tax oncigarettes rises. To reduce total tobacco usage, policymakers might alsowant to increase the tax on cigars and chewing tobacco, or pursue sometype of public education program.9. Quantity supplied equals quantity demanded at a price of $6 and quantity of 81pizzas (Figure 4-26). If price were greater than $6, quantity supplied wouldexceed quantity demanded, so suppliers would reduce their price to gain sales.If price were less than $6, quantity demanded would exceed quantity supplied, so suppliers could raise their price without losing sales. In both cases, the price would continue to adjust until it reached $6, the only price at which there'sneither surplus nor shortage.Figure 4-2610. a. If the price of flour falls, since flour is an ingredient in bagels, the supplycurve for bagels would shift to the right. The result, shown in Figure 4-27,would be a fall in the price of bagels and a rise in the equilibrium quantityof bagels.Since cream cheese is a complement to bagels, the rise in quantitydemanded of bagels increases the demand for cream cheese, as shown inFigure 4-28. The result is a rise in both the equilibrium price and quantityof cream cheese. So, a fall in the price of flour indeed raises both theequilibrium price of cream cheese and the equilibrium quantity of bagels.Figure 4-27Figure 4-28What happens if the price of milk falls Since milk is an ingredient in cream cheese, the fall in the price of milk leads to an increase in the supply of cream cheese. This leads to a decrease in the price of cream cheese (Figure 4-29), rather than a rise in the price of cream cheese. So a fall in the price of milk couldn't have been responsible for the pattern observed.Figure 4-29Figure 4-30b. In part (a), we found that a fall in the price of flour led to a rise in theprice of cream cheese and a rise in the equilibrium quantity of bagels. Ifthe price of flour rose, the opposite would be true; it would lead to a fallin the price of cream cheese and a fall in the equilibrium quantity ofbagels. Since the question says the equilibrium price of cream cheese has risen, it couldn't have been caused by a rise in the price of flour.What happens if the price of milk rises From part (a), we found that a fallin the price of milk caused a decline in the price of cream cheese, so arise in the price of milk would cause a rise in the price of cream cheese.Since bagels and cream cheese are complements, the rise in the price ofcream cheese would reduce the demand for bagels, as Figure 4-30 shows.The result is a decline in the equilibrium quantity of bagels. So a rise inthe price of milk does cause both a rise in the price of cream cheese anda decline in the equilibrium quantity of bagels.11. a. As Figure 4-31 shows, the supply curve is vertical. The constant supplymakes sense because the basketball arena has a fixed number of seats nomatter what the price.Figure 4-31b. Quantity supplied equals quantity demanded at a price of $8. Theequilibrium quantity is 8,000 tickets.c.Price Quantity Demanded Quantity Supplied$ 4 14,0008,0008 11,0008,000128,0008,000165,0008,000202,0008,000The new equilibrium price will be $12, which equates quantity demandedto quantity supplied. The equilibrium quantity is 8,000 tickets.12. The executives are confusing changes in demand with changes in quantitydemanded. Figure 4-32 shows the demand curve prior to the marketing campaign (D1), and after the campaign (D2). The marketing campaign increased the demand for champagne, as shown, leading to a higher equilibrium price and quantity. Theinfluence of the higher price on demand is already reflected in the outcome. It's impossible for the scenario outlined by the executives to occur.Figure 4-32。
曼昆_经济学原理答案_英文版chp4
Chapter 4The market forces of supply and demandSolutions to text problemsQZ What is a market? What does it mean for a market to be competitive? (page 60)A market is a group of buyers (who determine demand) and a group of sellers (who determine supply) of a particular good or service. A competitive market is one in which there are many buyers and many sellers so that each has a negligible impact on the market price.QZ List the determinants of the demand for pizza. Give an example of a demand schedule for pizza, and graph the implied demand curve. Give an example of something that would shift this demand curve. Would a change in the price of pizza shift this demand curve? (page 66)The determinants of the quantity of pizza demanded should include price, income, prices of related goods, tastes, expectations and the number of buyers.Here is an example of a demand schedule for pizza:Price of pizza slice Number of pizza slices demanded$0.00 100.25 90.50 80.75 71.00 61.25 51.50 41.75 32.00 22.25 12.50 0The demand curve is graphed in Figure 4.1.Figure 4.1Chapter 4: The market forces of supply and demand 31Examples of things that would shift the demand curve include changes in income, prices of related goods like soft drink or hot dogs, tastes, and expectations about future income or prices.A change in the price of pizza would not shift this demand curve; it would only move from one point to another along the curve.QZ List the determinants of the supply of pizza. Give an example of a supply schedule for pizza, and graph the implied supply curve. Give an example of something that would shift this supply curve. Would a change in the price of pizza shift this supply curve? (page 71)The determinants of the quantity of pizza supplied include the price of pizza, the prices of inputs into pizza production, the technology for producing pizza, expectations about things like the future price of pizza and the number of suppliers of pizza.Here is an example of a supply schedule for pizza:Price of pizza slice Number of pizza slices supplied$0.00 00.25 1000.50 2000.75 3001.00 4001.25 5001.50 6001.75 7002.00 8002.25 9002.50 1000The supply curve is graphed in Figure 4.2.Figure 4.232 Principles of Economics, Third edition, Instructor’s ManualExamples of things that would shift the supply curve include changes in prices of inputs like tomato sauce and cheese, changes in technology like more efficient pizza ovens or automatic dough makers, and changes in expectations about the future price of pizza.A change in the price of pizza would not shift this supply curve; it would only move from one point to another along the curve.QZ Analyse what happens to the market for pizza if the price of tomatoes rises. Analyse what happens to the market for pizza if the price of hamburgers falls. (page 75)If the price of tomatoes rises, the supply curve for pizza shifts to the left because of the increased price of an input into pizza production, however there is no effect on demand. The shift to the left of the supply curve causes the equilibrium price to rise and the equilibrium quantity to decline, as Figure 4.3 shows.Figure 4.3Chapter 4: The market forces of supply and demand 33 If the price of hamburgers falls, the demand curve for pizza shifts to the left because the lower price of hamburgers will lead consumers to buy more hamburgers and less pizza, but there is no effect on supply. The shift to the left of the demand curve causes the equilibrium price to fall and the equilibrium quantity to decline, as Figure 4.4 shows.Figure 4.434 Principles of Economics, Third edition, Instructor’s ManualQuestions for review (page 79)1 A competitive market is a market in which there are many buyers and many sellers so that each has anegligible impact on the market price.2The quantity of a good that buyers demand is determined by the price of the good, income, the prices of related goods, tastes, expectations and the number of buyers.3The demand schedule is a table that shows the relationship between the price of a good and the quantity demanded. The demand curve is the downward-sloping line relating price and quantity demanded. The demand schedule and demand curve are related because the demand curve is simplya graph showing the points in the demand schedule.4The demand curve slopes downward because of the law of demand—other things equal, when the price of a good rises, the quantity demanded of the good falls. People buy less of a good when its price rises, both because they can't afford to buy as much and because they switch to purchasing other goods.5 A change in consumers' tastes leads to a shift of the demand curve. A change in price leads to amovement along the demand curve.6The quantity of a good that sellers supply is determined by the price of the good, input prices, technology, expectations and the number of suppliers.7 A supply schedule is a table showing the relationship between the price of a good and the quantity aproducer is willing and able to supply. The supply curve is the upward-sloping line relating price and quantity supplied. The supply schedule and the supply curve are related because the supply curve is simply a graph showing the points in the supply schedule.8The supply curve slopes upward because when the price is high, suppliers' profits increase, so they supply more output to the market. The result is the law of supply—other things equal, when the price of a good rises, the quantity supplied of the good also rises.9 A change in producers' technology leads to a shift in the supply curve. A change in price leads to amovement along the supply curve.10The equilibrium of a market is the point at which the demand and supply curves intersect. At the equilibrium price, the quantity of the good that buyers are willing and able to buy exactly balances the quantity that sellers are willing and able to sell. If the price is above the equilibrium price, sellers want to sell more than buyers want to buy, so there is a surplus. Sellers try to increase their sales by cutting prices; that continues until they reach the equilibrium price. If the price is below theequilibrium price, buyers want to buy more than sellers want to sell, so there is a shortage. Sellers can raise their price without losing customers; that continues until they reach the equilibrium price. 11When the price of beer rises, the demand for pies declines, because beer and pies are complements and people want to buy less beer. When we say the demand for pies declines, we mean that the demand curve for pies shifts to the left as in Figure 4.5 below. The supply curve for pies isn'taffected. With a shift to the left in the demand curve, the equilibrium price and quantity both decline, as the figure shows. Thus the quantity of pies supplied and demanded both fall. In summary, supply is unchanged, demand is decreased, quantity supplied declines, quantity demanded declines, and the price falls.Chapter 4: The market forces of supply and demand 35Figure 4.512 Prices play a vital role in market economies because they bring markets into equilibrium. If the priceis different from its equilibrium level, quantity supplied and quantity demanded aren't equal. The resulting surplus or shortage leads suppliers to adjust the price until equilibrium is restored. Prices thus serve as signals that guide economic decisions and allocate scarce resources.Problems and applications (page 80)1 a The cyclone damages the banana harvest, reducing the supply of bananas. This can be seen inFigure 4.6 as a shift to the left in the supply curve for bananas. The new equilibrium price is higher than the old equilibrium price. Figure 4.6P r i c e o f p i e sQuantity of bananasP r i c e o f b a n a n a sQuantity of pies36 Principles of Economics, Third edition, Instructor’s Manualb People often go to the pictures during school holidays so demand for picture tickets is highduring school holidays. When school holidays end, fewer people go to the pictures. The result, as shown in Figure 4.7, is a shift to the left in the demand curve. The equilibrium price of picture tickets is thus lower when school holidays end, as the figure shows. Figure 4.7c When a war breaks out in the Middle East, many markets are affected. Since much oilproduction takes place there, the war disrupts oil supplies, shifting the supply curve for petrol tothe left, as shown in Figure 4.8. The result is a rise in the equilibrium price of petrol. With a higher price for petrol, the cost of operating a big car, like a Ford Falcon, will increase. As a result, the demand for used Ford Falcons will decline, as people in the market for cars won't find Falcons as attractive. In addition, some people who already own Falcons will try to sell them. The result is that the demand curve for used Falcons shifts to the left, while the supply curve shifts to the right, as shown in Figure 4.9. The result is a decline in the equilibrium price of used Falcons.Figure 4.8Quantity of theatre tickets P r i c e o f t h e a t r e t i c k e t sP r i c e o f p e t r o l Quantity of petrolChapter 4: The market forces of supply and demand 37Figure 4.92 The statement that ‘an increase in the demand for notebooks raises the quantity of notebooksdemanded, but not the quantity supplied’ is false, in general. As Figure 4.10 shows, the increase in demand for notebooks results in an increased quantity supplied. The only way the statement would be true is if the supply curve were perfectly inelastic, as shown in Figure 4.11. Figure 4.10P r i c e o f u s e d F o r d F a l c o n sQuantity of used Ford Falcons38 Principles of Economics, Third edition, Instructor’s ManualFigure 4.113 a If people decide to have more children (a change in tastes), they'll want larger vehicles forhauling their kids around, so the demand for station wagons will increase. Supply won't be affected. The result is a rise in both price and quantity, as Figure 4.12 shows. Figure 4.12Quantity of Station WagonsP r i c e o f S t a t i o n W a g o n sChapter 4: The market forces of supply and demand 39b If a strike by steelworkers raises steel prices, the costs of producing a station wagon rise (a risein input prices), so the supply of station wagons decreases. Demand won't be affected. The result is a rise in the price of station wagons and a decline in the quantity, as Figure 4.13 shows.Figure 4.13c The development of new automated machinery for the production of station wagons is animprovement in technology. The reduction in firms' costs results in an increase in supply. Demand isn't affected. The result is a decline in the price of station wagons and an increase in the quantity, as Figure 4.14 shows.Figure 4.14d The rise in the price of minivans affects station wagon demand because minivans are substitutesfor station wagons (that is, there's a rise in the price of a related good). The result is an increase in demand for station wagons. Supply isn't affected. In equilibrium, the price and quantity of station wagons both rise, as Figure 4.12 shows.P r i c e o f S t a t i o n W a g o n sQuantity of Station WagonsP r i c e o f S t a t i o n W a g o n sQuantity of Station Wagonse The reduction in peoples' wealth caused by a stock market crash reduces their income, leading toa reduction in the demand for station wagons, since station wagons are a normal good. Supply isn’t affected. As a result, both price and quantity decline, as Figure 4.15 shows. Figure 4.154 Technological advances that reduce the cost of producing computer chips represent a decline in aninput price for producing a computer. The result is a shift to the right in the supply of computers, as shown in Figure 4.16. The equilibrium price falls and the equilibrium quantity rises, as the figure shows. Figure 4.16Quantity of Station WagonsP r i c e o f S t a t i o n W a g o n sSince computer software is a complement to computers, the increased equilibrium quantity of computers increases the demand for software. As Figure 4.17 shows, the result is a rise in both the equilibrium price and quantity of software.Figure 4.17Since typewriters are substitutes for computers, the increased equilibrium quantity of computers reduces the demand for typewriters. As Figure 4.18 shows, the result is a decline in both theequilibrium price and quantity of typewriters.Figure 4.185 a When an outbreak of ‘foot and mouth’ disease hits sheep farms in New Zealand, it raises inputprices for producing woollen jumpers. As a result, the supply of woollen jumpers shifts to the left, as shown in Figure 4.19. The new equilibrium has a higher price and lower quantity of woollen jumpers. Figure 4.19b A decline in the price of leather jackets leads more people to buy leather jackets, reducing thedemand for woollen jumpers. The result, shown in Figure 4.20, is a decline in both theequilibrium price and quantity of woollen jumpers.Figure 4.20Quantity of woollen jumpers P r i c e o f w o o l l e n j u m p e r sQuantity of woollen jumpersP r i c e o f w o o l l e n j u m p e r sc Kylie wearing a woollen jumper raises the demand for woollen jumpers, as shown in Figure4.21. The result is an increase in both the equilibrium price and quantity of woollen jumpers. Figure 4.21d The invention of new knitting machines increases the supply of woollen jumpers. As Figure 4.22shows, the result is a reduction in the equilibrium price and an increase in the equilibriumquantity of woollen jumpers.Figure 4.22P r i c e o f W o o l l e n J u m p e r sQuantity of Woollen Jumpers Quantity of Woollen JumpersP r i c e o f W o o l l e n J u m p e r s6 A temporarily high birth rate in the year 2005 leads to opposite effects on the price of babysittingservices in the years 2010 and 2020. In the year 2010, there are more 5-year-olds who need sitters, so the demand for babysitting services rises, as shown in Figure 4.23. The result is a higher price for babysitting services in 2010. However, in the year 2020, the increased number of 15-year-olds shifts the supply of babysitting services to the right, as shown in Figure 4.24. The result is a decline in the price of babysitting services.Figure 4.23Figure 4.247Since tomato sauce is a complement for hot dogs, when the price of hot dogs rises, the quantity demanded of hot dogs falls, thus reducing the demand for tomato sauce, causing both price and quantity of tomato sauce to fall. Since the quantity of tomato sauce falls, the demand for tomatoes by tomato sauce producers falls, so both price and quantity of tomatoes fall. When the price of tomatoes falls, producers of tomato juice face lower input prices, so the supply curve for tomato juice shifts down, causing the price of tomato juice to fall and the quantity of tomato juice to rise. The fall in the price of tomato juice causes people to substitute tomato juice for orange juice, so the demand for orange juice declines, causing the price and quantity of orange juice to fall. Now you can see clearly why a rise in the price of hot dogs leads to a fall in price of orange juice!8 a Cigars and chewing tobacco are substitutes for cigarettes, since a higher price for cigaretteswould increase demand for cigars and pipe tobacco.b An increase in the tax on cigarettes leads to increased demand for cigars and pipe tobacco. Theresult, as shown in Figure 4.25 for cigars, is a rise in both the equilibrium price and quantity of cigars and pipe tobacco.Figure 4.25c The results in part (b) showed that a tax on cigarettes leads people to substitute cigars and pipetobacco for cigarettes when the tax on cigarettes rises. To reduce total tobacco usage,policymakers might also want to increase the tax on cigars and pipe tobacco, or pursue sometype of public education program.9Quantity supplied equals quantity demanded at a price of $6 and quantity of 81 pizzas (Figure 4.26).If price were greater than $6, quantity supplied would exceed quantity demanded, so suppliers would reduce their price to gain sales. If price were less than $6, quantity demanded would exceed quantity supplied, so suppliers could raise their price without losing sales. In both cases, the price would continue to adjust until it reached $6, the only price at which there is neither surplus nor shortage. Figure 4.2610 a If the price of flour falls, since flour is an ingredient in bagels, the supply curve for bagels wouldshift to the right. The result, shown in Figure 4.27, would be a fall in the price of bagels and arise in the equilibrium quantity of bagels. Since cream cheese is a complement to bagels, the rise in quantity demanded of bagels increases the demand for cream cheese, as shown in Figure 4.28.The result is a rise in both the equilibrium price and quantity of cream cheese. So, a fall in theprice of flour indeed raises both the equilibrium price of cream cheese and the equilibriumquantity of bagels.Figure 4.27Figure 4.28What happens if the price of milk falls? Since milk is an ingredient in cream cheese, the fall in the price of milk leads to an increase in the supply of cream cheese. This leads to a decrease in the price of cream cheese (Figure 4.29), rather than a rise in the price of cream cheese. So a fall in the price of milk couldn't have been responsible for the pattern observed.Figure 4.29b In part (a), we found that a fall in the price of flour led to a rise in the price of cream cheese anda rise in the equilibrium quantity of bagels. If the price of flour rose, the opposite would be true;it would lead to a fall in the price of cream cheese and a fall in the equilibrium quantity ofbagels. Since the question says the equilibrium price of cream cheese has risen, it couldn't have been caused by a rise in the price of flour.What happens if the price of milk rises? From part (a), we found that a fall in the price of milk caused a decline in the price of cream cheese, so a rise in the price of milk would cause a rise in the price of cream cheese. Since bagels and cream cheese are complements, the rise in the price of cream cheese would reduce the demand for bagels, as Figure 4.30 shows. The result is adecline in the equilibrium quantity of bagels. So a rise in the price of milk does cause both a rise in the price of cream cheese and a decline in the equilibrium quantity of bagels.Figure 4.3011 a As Figure 4.31 shows, the supply curve is vertical. The constant supply makes sense because thepicture theatre has a fixed number of seats no matter what the price.Figure 4.31b Quantity supplied equals quantity demanded at a price of $8. The equilibrium quantity is 800tickets. cPriceQuantity demandedQuantity supplied$4 1400 800 8 1100 800 12 800 800 16 500 800 20 200800The new equilibrium price will be $12, which equates quantity demanded to quantity supplied. The equilibrium quantity is 800 tickets.P r i c e o f p i c t u r e t h e a t r e t i c k e t sQuantity of picture theatre tickets 80012The executives are confusing changes in demand with changes in quantity demanded. Figure 4.32 shows the demand curve prior to the marketing campaign (D1), and after the campaign (D2). The marketing campaign increased the demand for champagne, as shown, leading to a higher equilibrium price and quantity. The influence of the higher price on demand is already reflected in the outcome.It's impossible for the scenario outlined by the executives to occur.Figure 4.3213 At equilibrium Q S=Q D. Therefore here:1400 + 700P = 1600 – 300P1000P = 200P = $0.20The equilibrium price is $0.20 per bar of chocolate. Substitute this into either Q S or Q D to get the equilibrium quantity of 1540 bars of chocolate.。
曼昆经济学原理课后答案
曼昆经济学原理课后答案曼昆经济学原理是经济学入门课程中的经典教材，深受广大学生和经济学爱好者的喜爱。
在学习曼昆经济学原理课程时，课后习题是非常重要的一部分，通过做习题可以加深对知识点的理解，检验自己的学习成果。
下面是对曼昆经济学原理课后习题的一些答案解析，希望能够帮助大家更好地掌握课程内容。
1. 为什么经济学家对稀缺性问题感兴趣？经济学家对稀缺性问题感兴趣是因为资源有限而需求无限，这就导致了资源的稀缺性。
经济学家希望通过研究资源的稀缺性问题，找到合理的资源配置方式，以实现资源的最大效益。
2. 什么是机会成本？为什么机会成本是个重要概念？机会成本是指为了得到某种东西而放弃的东西的价值。
它是个重要概念，因为在资源有限的情况下，人们需要在各种选择之间进行权衡，了解机会成本有助于人们做出更明智的决策。
3. 什么是边际分析？为什么它对理解个体决策和市场行为很重要？边际分析是指对增加或减少一单位的行为进行分析，以便了解这种行为对总效用或总成本的影响。
它对理解个体决策和市场行为很重要，因为在现实生活中，人们所面临的决策往往是边际决策，边际分析可以帮助人们更好地理解这些决策。
4. 弹性是什么？弹性的概念对理解需求和供给有何重要性？弹性是指一种变化的程度，可以是价格变化对数量变化的影响，也可以是收入变化对需求变化的影响。
弹性的概念对理解需求和供给有重要性，因为它可以帮助我们预测市场的变化，指导企业和政府的决策。
5. 什么是市场？市场如何协调买者和卖者的行为？市场是指买者和卖者进行交换的地方。
市场通过价格机制来协调买者和卖者的行为，当价格上涨时，供给增加，需求减少，直到市场达到新的均衡；当价格下跌时，供给减少，需求增加，也会达到新的均衡。
6. 什么是生产可能性边界？生产可能性边界如何展示机会成本的概念？生产可能性边界是指在资源和技术固定的情况下，一个国家能够生产的各种商品和服务的组合。
生产可能性边界展示了机会成本的概念，因为它告诉我们，如果一个国家要增加生产某种商品，就必须放弃生产其他商品，这就是机会成本的体现。
曼昆经济学原理英文版教案加习题答案第4章THE MARKET FORCES OF SUPPLY AND DEMAND
51WHAT’S NEW IN THE S EVENTH EDITION:The In the News feature “Price Increases after Disasters” has been updated with a new article.LEARNING OBJECTIVES:By the end of this chapter, students should understand:➢ what a competitive market is.➢ what determines the demand for a good in a competitive market.➢ what determines the supply of a good in a competitive market.➢ how supply and demand together set the price of a good and the quantity sold.➢ the key role of prices in allocating scarce resources in market economies.CONTEXT AND PURPOSE:Chapter 4 is the first chapter in a three-chapter sequence that deals with supply and demand and how markets work. Chapter 4 shows how supply and demand for a good determines both the quantity produced and the price at which the good sells. Chapter 5 will add precision to the discussion of supply and demand by addressing the concept of elasticity —the sensitivity of the quantity supplied and quantity demanded to changes in economic variables. Chapter 6 will address the impact of government policies on prices and quantities in markets.The purpose of Chapter 4 is to establish the model of supply and demand. The model of supply and demand is the foundation for the discussion for the remainder of this text. For this reason, time spent studying the concepts in this chapter will return benefits to your students throughout their study of economics. Many instructors would argue that this chapter is the most important chapter in the text.THE MARKET FORCES OF SUPPLY AND DEMAND52 ❖Chapter 4/The Market Forces of Supply and DemandKEY POINTS:• Economists use the model of supply and demand to analyze competitive markets. In a competitive market, there are many buyers and sellers, each of whom has little or no influence on the market price.• The demand curve shows how the quantity of a good demanded depends on the price. According to the law of demand, as the price of a good falls, the quantity demanded rises. Therefore, the demand curve slopes downward.• In addition to price, other determinants of how much consumers want to buy include income, the prices of substitutes and complements, tastes, expectations, and the number of buyers. If one of these factors changes, the demand curve shifts.• The supply curve shows how the quantity of a good supplied depends on the price. According to the law of supply, as the price of a good rises, the quantity supplied rises. Therefore, the supply curve slopes upward.• In addition to price, other determinants of how much producers want to sell include input prices, technology, expectations, and the number of sellers. If one of these factors changes, the supply curve shifts.• The intersection of the supply and demand curves determines the market equilibrium. At the equilibrium price, the quantity demanded equals the quantity supplied.• The behavior of buyers and sellers naturally drives markets toward their equilibrium. When the market price is above the equilibrium price, there is a surplus of the good, which causes the market price to fall. When the market price is below the equilibrium price, there is a shortage, which causes the market price to rise.• To analyze how any event influences a market, we use the supply-and-demand diagram to examine how the event affects equilibrium price and quantity. To do this we follow three steps. First, we decide whether the event shifts the supply curve or the demand curve (or both). Second, we decide which direction the curve shifts. Third, we compare the new equilibrium with the initial equilibrium.• In market economies, prices are the signals that guide economic decisions and thereby allocate scarce resources. For every good in the economy, the price ensures that supply and demand are in balance. The equilibrium price then determines how much of the good buyers choose to consume and how much sellers choose to produce.Chapter 4/The Market Forces of Supply and Demand ❖ 53CHAPTER OUTLINE: I. Markets and CompetitionA. What Is a Market?1. Definition of market: a group of buyers and sellers of a particular good or service.2. Markets can take many forms and may be organized (agricultural commodities) or lessorganized (ice creamB. What Is Competition?1. Definition of competitive market: a market in which there are so many buyers andso many sellers that each has a negligible impact on the market price.2. Each buyer knows that there are several sellers from which to choose. Sellers know that each buyer purchases only a small amount of the total amount sold.C. In this chapter, we will assume that markets are perfectly competitive.1. Characteristics of a perfectly competitive market:a. The goods being offered for sale are exactly the same.b. The buyers and sellers are so numerous that no single buyer or seller has any influence over the market price.2. Because buyers and sellers must accept the market price as given, they are often called "price takers."3. Not all goods are sold in a perfectly competitive market.a. A market with only one seller is called a monopoly market.b. Other markets fall between perfect competition and monopoly.54 ❖ Chapter 4/The Market Forces of Supply and DemandD. We will start by studying perfect competition.1. Perfectly competitive markets are the easiest to analyze because buyers and sellers take the price as a given.2. Because some degree of competition is present in most markets, many of the lessons that we learn by studying supply and demand under perfect competition apply in morecomplicated markets.II. DemandA. The Demand Curve: The Relationship between Price and Quantity Demanded1. Definition of quantity demanded: the amount of a good that buyers are willing andable to purchase.2. One important determinant of quantity demanded is the price of the product.a. Quantity demanded is negatively related to price. This implies that the demand curve isdownward sloping.b. Definition of law of demand: the claim that, other things being equal, thequantity demanded of a good falls when the price of the good rises .3. Definition of demand schedule: a table that shows the relationship between theprice of a good and the quantity demanded. Price of Ice-Cream ConeQuantity of Cones Demanded$0.0012 $0.5010 $1.008 $1.506 $2.004 $2.502 $3.00Figure 1Make sure that you explain that, when we discuss the relationship between quantity demanded and price, we hold all other variables constant. You will need toemphasize this more than once to ensure that students understand why a change inprice leads to a movement along the demand curve.Chapter 4/The Market Forces of Supply and Demand ❖ 554. Definition of demand curve: a graph of the relationship between the price of a good and the quantity demanded.a. Price is generally drawn on the vertical axis.b. Quantity demanded is represented on the horizontal axis. B. Market Demand versus Individual Demand1. The market demand is the sum of all of the individual demands for a particular good orservice.2. The demand curves are summed horizontally —meaning that the quantities demanded are added up for each level of price.3. The market demand curve shows how the total quantity demanded of a good varies with the price of the good, holding constant all other factors that affect how much consumers want to buy.C. Shifts in the Demand Curve1. Because the market demand curve holds other things constant, it need not be stable overtime.56 ❖ Chapter 4/The Market Forces of Supply and Demand2. If any of these other factors change, the demand curve will shift.a. An increase in demand is represented by a shift of the demand curve to the right.b. A decrease in demand is represented by a shift of the demand curve to the left.3. Incomea. The relationship between income and quantity demanded depends on what type of good the product is.b. Definition of normal good: a good for which, other things equal, an increase in income leads to an increase in demand.c. Definition of inferior good: a good for which, other things equal, an increase inincome leads to a decrease in demand.4. Prices of Related Goodsa. Definition of substitutes: two goods for which an increase in the price of one good leads to an increase in the demand for the other.b. Definition of complements: two goods for which an increase in the price of one good leads to a decrease in the demand for the other.5. Tastes6. Expectationsa. Future incomeb. Future prices7. Number of BuyersChapter 4/The Market Forces of Supply and Demand ❖57D. Case Study: Two Ways to Reduce the Quantity of Smoking Demanded1. Public service announcements, mandatory health warnings on cigarette packages, and theprohibition of cigarette advertising on television are policies designed to reduce the demandfor cigarettes (and shift the demand curve to the left).2. Raising the price of cigarettes (through tobacco taxes) lowers the quantity of cigarettesdemanded.a. The demand curve does not shift in this case, however.b. An increase in the price of cigarettes can be shown by a movement along the originaldemand curve.3. Studies have shown that a 10% increase in the price of cigarettes causes a 4% reduction inthe quantity of cigarettes demanded. For teens, a 10% increase in price leads to a 12% dropin quantity demanded.4. Studies have also shown that a decrease in the price of cigarettes is associated with greateruse of marijuana. Thus, it appears that tobacco and marijuana are complements.III. SupplyA. The Supply Curve: The Relationship between Price and Quantity Supplied1. Definition of quantity supplied: the amount of a good that sellers are willing andable to sell.a. Quantity supplied is positively related to price. This implies that the supply curve will beupward sloping.b. Definition of law of supply: the claim that, other things equal, the quantitysupplied of a good rises when the price of the good rises.2. Definition of supply schedule: a table that shows the relationship between the priceof a good and the quantity supplied.58 ❖ Chapter 4/The Market Forces of Supply and Demand3. Definition of supply curve: a graph of the relationship between the price of a good and the quantity supplied. Price of Ice-Cream ConeQuantity of Cones Supplied$0.000 $0.50 0 $1.001 $1.502 $2.003 $2.504 $3.005B. Market Supply versus Individual Supply1. The market supply curve can be found by summing individual supply curves.2. Individual supply curves are summed horizontally at every price.3. The market supply curve shows how the total quantity supplied varies as the price of thegood varies.C. Shifts in the Supply Curve1. Because the market supply curve holds other things constant, the supply curve will shift ifany of these factors changes.a. An increase in supply is represented by a shift of the supply curve to the right.b. A decrease in supply is represented by a shift of the supply curve to the left.Figure 5Figure 7Figure 6You will want to take time to emphasize the difference between a “change in supply” and a “change in quantity supplied.”Chapter 4/The Market Forces of Supply and Demand ❖ 592. Input Prices3. Technology4. Expectations5. Number of Sellers IV. Supply and Demand TogetherA. Equilibrium1. The point where the supply and demand curves intersect is called the market’s equilibrium.2. Definition of equilibrium: a situation in which the market price has reached thelevel at which quantity supplied equals quantity demanded.3. Definition of equilibrium price: the price that balances quantity supplied andquantity demanded.4. The equilibrium price is often called the "market-clearing" price because both buyers andsellers are satisfied at this price.Table 2Figure 8 Students will benefit from seeing equilibrium using both a graph and a supply-and-demand schedule. The schedule will also make it easier for students to understand concepts such as shortages and surpluses.60 ❖Chapter 4/The Market Forces of Supply and Demand5. Definition of equilibrium quantity: the quantity supplied and the quantitydemanded at the equilibrium price.6. If the actual market price is higher than the equilibrium price, there will be a surplus of thegood.Figure 9a. Definition of surplus: a situation in which quantity supplied is greater thanquantity demanded.b. To eliminate the surplus, producers will lower the price until the market reachesequilibrium.7. If the actual price is lower than the equilibrium price, there will be a shortage of the good.a. Definition of shortage: a situation in which quantity demanded is greater thanquantity supplied.b. Sellers will respond to the shortage by raising the price of the good until the marketreaches equilibrium.8. Definition of the law of supply and demand: the claim that the price of any goodadjusts to bring the supply and demand for that good into balance.B. Three Steps to Analyzing Changes in Equilibrium 1. Decide whether the event shifts the supply or demand curve (or perhaps both). 2. Determine the direction in which the curve shifts.3. Use the supply-and-demand diagram to see how the shift changes the equilibrium price andquantity. C. Example: A change in market equilibrium due to a shift in demand —the effect of hot weather onthe market for ice cream.D. Shifts in Curves versus Movements along Curves1. A shift in the demand curve is called a "change in demand." A shift in the supply curve iscalled a "change in supply."2. A movement along a fixed demand curve is called a "change in quantity demanded." Amovement along a fixed supply curve is called a "change in quantity supplied." E. Example: A change in market equilibrium due to a shift in supply —the effect of a hurricane thatdestroys part of the sugar-cane crop and drives up the price of sugar.F. Example: Shifts in both supply and demand —the effect of hot weather and a hurricane thatdestroys part of the sugar cane crop. G. Summary1. When an event shifts the supply or demand curve, we can examine the effects on theequilibrium price and quantity.ALTERNATIVE CLASSROOM EXAMPLE:Go through these examples of events that would shift either the demand or supply of #2 lead pencils:▪ an increase in the income of consumers▪ an increase in the use of standardized exams (using opscan forms) ▪ a decrease in the price of graphite (used in the production of pencils) ▪ a decrease in the price of ink pens ▪ the start of a school year▪ new technology that lowers the cost of producing pencils.2. Table 4 reports the end results of these shifts in supply and demand.H. In the News: Price Increases after Disasters1. When a disaster strikes a region, many good experience an increase in demand or a decreasein supply resulting in upward pressure on prices.2. This article from defends price increases following natural disasters as a naturalresult of market interactions.V. Conclusion: How Prices Allocate ResourcesA. The model of supply and demand is a powerful tool for analyzing markets.B. Supply and demand together determine the prices of the economy’s goods and services.1. These prices serve as signals that guide the allocation of scarce resources in the economy.2. Prices determine who produces each good and how much of each good is produced.SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. A market is a group of buyers (who determine demand) and a group of sellers (whodetermine supply) of a particular good or service. A perfectly competitive market is one inwhich there are many buyers and many sellers of an identical product so that each has anegligible impact on the market price.2. Here is an example of a monthly demand schedule for pizza:Price of Pizza Slice Number of Pizza Slices Demanded$ 0.00 100.25 90.50 80.75 71.00 61.25 51.50 41.75 32.00 22.25 12.50 0The demand curve is graphed in Figure 1.Figure 1Examples of things that would shift the demand curve include changes in income, prices ofrelated goods like soda or hot dogs, tastes, expectations about future income or prices, andthe number of buyers.A change in the price of pizza would not shift this demand curve; it would only lead to amovement from one point to another along the same demand curve.3. Here is an example of a monthly supply schedule for pizza:Price of Pizza Slice Number of PizzaSlices Supplied$ 0.00 00.25 1000.50 2000.75 3001.00 4001.25 5001.50 6001.75 7002.00 8002.25 9002.50 1000The supply curve is graphed in Figure 2.Figure 2Figure 3Examples of things that would shift the supply curve include changes in prices of inputs like tomato sauce and cheese, changes in technology like more efficient pizza ovens or automatic dough makers, changes in expectations about the future price of pizza, or a change in the number of sellers.A change in the price of pizza would not shift this supply curve; it would only lead to amovement from one point to another along the same supply curve.4. If the price of tomatoes rises, the supply curve for pizza shifts to the left because there hasbeen an increase in the price of an input into pizza production, but there is no shift indemand. The shift to the left of the supply curve causes the equilibrium price to rise and the equilibrium quantity to decline, as Figure 3 shows.If the price of hamburgers falls, the demand curve for pizza shifts to the left because thelower price of hamburgers will lead consumers to buy more hamburgers and fewer pizzas,but there is no shift in supply. The shift to the left of the demand curve causes theequilibrium price to fall and the equilibrium quantity to decline, as Figure 4 shows.Figure 4Questions for Review1. A competitive market is a market in which there are many buyers and many sellers of anidentical product so that each has a negligible impact on the market price. Another type ofmarket is a monopoly, in which there is only one seller. There are also other markets that fallbetween perfect competition and monopoly.2. The demand schedule is a table that shows the relationship between the price of a good andthe quantity demanded. The demand curve is the downward-sloping line relating price andquantity demanded. The demand schedule and demand curve are related because thedemand curve is simply a graph showing the points in the demand schedule.The demand curve slopes downward because of the law of demand—other things beingequal, when the price of a good rises, the quantity demanded of the good falls. People buyless of a good when its price rises, both because they cannot afford to buy as much andbecause they switch to purchasing other goods.3. A change in consumers' tastes leads to a shift of the demand curve. If the change inconsumers' tastes leads to an increase in demand, consumers want to buy more of this goodat every price level. A change in price leads to a movement along the demand curve.Because price is measured on the vertical axis, a change in the price represents a movementalong the demand curve.4. Because Popeye buys more spinach when his income falls, spinach is an inferior good for him.His demand curve for spinach shifts out to the right as a result of the decrease in his income.5. A supply schedule is a table showing the relationship between the price of a good and thequantity a producer is willing and able to supply. The supply curve is the upward-sloping linerelating price and quantity supplied. The supply schedule and the supply curve are related because the supply curve is simply a graph showing the points in the supply schedule.The supply curve slopes upward because when the price is high, suppliers' profits increase, so they supply more output to the market. The result is the law of supply—other things being equal, when the price of a good rises, the quantity supplied of the good also rises.6. A change in producers' technology leads to a shift in the supply curve. A change in priceleads to a movement along the supply curve.7. The equilibrium of a market is the point at which the quantity demanded is equal to quantitysupplied. If the price is above the equilibrium price, sellers want to sell more than buyers want to buy, so there is a surplus. Sellers try to increase their sales by cutting prices. That continues until they reach the equilibrium price. If the price is below the equilibrium price, buyers want to buy more than sellers want to sell, so there is a shortage. Sellers can raise their price without losing customers. That continues until they reach the equilibrium price.8. When the price of beer rises, the demand for pizza declines, because beer and pizza arecomplements and people want to buy less beer. When we say the demand for pizza declines, we mean that the demand curve for pizza shifts to the left as in Figure 5. The supply curve for pizza is not affected. With a shift to the left in the demand curve, the equilibrium price and quantity both decline, as the figure shows. Thus, the quantity of pizza supplied anddemanded both fall. In sum, supply is unchanged, demand is decreased, quantity supplied declines, quantity demanded declines, and the price falls.Figure 59. Prices play a vital role in market economies because they bring markets into equilibrium. Ifthe price is different from its equilibrium level, quantity supplied and quantity demanded are not equal. The resulting surplus or shortage leads suppliers to adjust the price untilequilibrium is restored. Prices thus serve as signals that guide economic decisions andallocate scarce resources.Quick Check Multiple Choice1. b2. b3. d4. b5. a6. cProblems and Applications1. a. Cold weather damages the orange crop, reducing the supply of oranges and raising theprice of oranges. This leads to a decline in the supply of orange juice because orangesare an important input in the production of orange juice. This can be seen in Figure 6 asa shift to the left in the supply curve for orange juice. The new equilibrium price is higherthan the old equilibrium price.Figure 6b. People often travel to the Caribbean from New England to escape cold weather, so thedemand for Caribbean hotel rooms is high in the winter. In the summer, fewer peopletravel to the Caribbean, because northern climates are more pleasant. The result, asshown in Figure 7, is a shift to the left in the demand curve. The equilibrium price ofCaribbean hotel rooms is thus lower in the summer than in the winter, as the figureshows.Figure 7c. When a war breaks out in the Middle East, many markets are affected. Because a largeproportion of oil production takes place there, the war disrupts oil supplies, shifting thesupply curve for gasoline to the left, as shown in Figure 8. The result is a rise in theequilibrium price of gasoline. With a higher price for gasoline, the cost of operating agas-guzzling automobile like a Cadillac will increase. As a result, the demand for usedCadillacs will decline, as people in the market for cars will not find Cadillacs as attractive.In addition, some people who already own Cadillacs will try to sell them. The result isthat the demand curve for used Cadillacs shifts to the left, while the supply curve shifts to the right, as shown in Figure 9. The result is a decline in the equilibrium price of used Cadillacs.Figure 8 Figure 92. The statement is false. As Figure 10 shows, in equilibrium the increase in demand fornotebooks results in an increased quantity demanded and the quantity supplied.Figure 10 Figure 113. a. If people decide to have more children, they will want larger vehicles for hauling theirkids around, so the demand for minivans will increase. Supply will not be affected. The result is a rise in both the price and the quantity sold, as Figure 12 shows.Figure 12 Figure 13b. If a strike by steelworkers raises steel prices, the cost of producing a minivan rises andthe supply of minivans decreases. Demand will not be affected. The result is a rise in the price of minivans and a decline in the quantity sold, as Figure 13 shows.c. The development of new automated machinery for the production of minivans is animprovement in technology. This reduction in firms' costs will result in an increase in supply. Demand is not affected. The result is a decline in the price of minivans and an increase in the quantity sold, as Figure 14 shows.Figure 14d. The rise in the price of sport utility vehicles affects minivan demand because sport utilityvehicles are substitutes for minivans. The result is an increase in demand for minivans.Supply is not affected. The equilibrium price and quantity of minivans both rise, as Figure12 shows.e. The reduction in peoples' wealth caused by a stock-market crash reduces their income,leading to a reduction in the demand for minivans, because minivans are likely a normal good. Supply is not affected. As a result, both the equilibrium price and the equilibrium quantity decline, as Figure 15 shows.Figure 154. a. DVDs and TV screens are likely to be complements because you cannot watch a DVDwithout a television. DVDs and movie tickets are likely to be substitutes because a movie can be watched at a theater or at home. TV screens and movie tickets are likely to besubstitutes for the same reason.b. The technological improvement would reduce the cost of producing a TV screen, shiftingthe supply curve to the right. The demand curve would not be affected. The result is that the equilibrium price will fall, while the equilibrium quantity will rise. This is shown inFigure 16.Figure 16c. The reduction in the price of TV screens would lead to an increase in the demand forDVDs because TV screens and DVDs are complements. The effect of this increase in the demand for DVDs is an increase in both the equilibrium price and quantity, as shown inFigure 17.Figure 17The reduction in the price of TV screens would cause a decline in the demand for movie tickets because TV screens and movie tickets are substitute goods. The decline in thedemand for movie tickets would lead to a decline in the equilibrium price and quantitysold. This is shown in Figure 18.Figure 185. Technological advances that reduce the cost of producing computer chips represent a declinein an input price for producing a computer. The result is a shift to the right in the supply of computers, as shown in Figure 19. The equilibrium price falls and the equilibrium quantity rises, as the figure shows.Figure 19Because computer software is a complement to computers, the lower equilibrium price of computers increases the demand for software. As Figure 20 shows, the result is a rise in both the equilibrium price and quantity of software.Figure 20Because typewriters are substitutes for computers, the lower equilibrium price of computers reduces the demand for typewriters. As Figure 21 shows, the result is a decline in both the equilibrium price and quantity of typewriters.Figure 216. a. When a hurricane in South Carolina damages the cotton crop, it raises input prices forproducing sweatshirts. As a result, the supply of sweatshirts shifts to the left, as shownin Figure 22. The new equilibrium price is higher and the new equilibrium quantity ofsweatshirts is lower.。
曼昆宏观经济学-课后答案-中文版
第一章宏观经济学的课后答案复习题1、由于整个经济的事件产生于许多家庭与许多企业的相互作用，所以微观经济学和宏观经济学必然是相互关联的。
当我们研究整个经济时，我们必须考虑个别经济行为者的决策。
由于总量只是描述许多个别决策的变量的总和，所以宏观经济理论必然依靠微观经济基础。
2、经济学家是用模型来解释世界，但一个经济学家的模型往往是由符号和方程式构成。
经济学家建立模型有助于解释GDP、通货膨胀和失业这类经济变量。
这些模型之所以有用是因为它们有助于我们略去无关的细节而更加明确地集中于重要的联系上。
模型有两种变量：内生变量和外生变量，一个模型的目的是说明外生变量如何影响内生变量。
3、经济学家通常假设，一种物品或劳务的价格迅速变动使得供给量与需求量平衡，即市场走向供求均衡。
这种假设称为市场出清。
在回答大多数问题时，经济学家用市场出清模型。
持续市场出清的假设并不完全现实。
市场要持续出清，价格就必须对供求变动作出迅速调整。
但是，实际上许多工资和价格调整缓慢。
虽然市场出清模型假设所有工资和价格都是有伸缩性的，但在现实世界中一些工资和价格是粘性的。
明显的价格粘性并不一定使市场出清模型无用。
首先偷格并不总是呆滞的，最终价格要根据供求的变动而调整。
市场出清模型并不能描述每一种情况下的经济，但描述了经济缓慢地趋近了均衡。
价格的伸缩性对研究我们在几十年中所观察到的实际GDP增长这类长期问题是一个好的假设。
第二章宏观经济学数据复习题1、GDP既衡量经济中所有人的收入，又衡量对经济物品与劳务的总支出。
GDP能同时衡量这两件事，是因为这两个量实际上是相同的：对整个经济来说，收入必定等于支出。
这个事实又来自于一个更有基本的事实：由于每一次交易都有一个买者和一个卖者，所以，一个买者支出的每一美元必然成为一个卖者的一美元收入。
2、CPI衡量经济中物价总水平。
它表示相对于某个基年一篮子物品与劳务价格的同样一篮子物品与劳务的现期价格。
3、劳工统计局把经济中每个人分为三种类型：就业、失业以及不属于劳动力。
曼昆宏观经济学-课后答案-中文版
(2)隐含的价格平减指数是帕氏指数，因为它是用一篮子可变物品计算的。CPI是拉斯派
尔指数，因为它是用一篮子固定物品计算的。由(1)中计算得2010年隐含的价格平减指数
是1.52，它表示物价从2000年到2010年上涨了5)0，o；而（1PI是1.6，它表示物价从2000年到2010
中交通管制的劳务。所以这些活动属于GDP的部分。转移支付是政府对不用交换物品和劳务的个
人的支付。转移支付是减少家庭可支配收入的税收的对立面，它增加家庭的可支配收入。例如对
老年人的社会保障支付、失业包厢以及退伍军人津贴，它不包括在GDP中。一
6、消费、投资、政府购买决定经济产出的需求，而生产要素与生产函数袂定经济产出的供求。
2000年消费的面包数量多于201 0年，CPI对面包加高其权重。由于面包价格上涨幅度高于
汽车，CPI就显示出物价水平较高的上涨。一
(3)这问题没有清晰的答案。理想的是，能有一个准确衡量生活成本的物价水平的指标。当一
种物品价格相对较昂贵时，人们会少买该种物品而多买其它物品。例子中，消费者少买面包多买
变。如果生产函数是规模报酬不变，经济中竞争性的利润最大化的企业的总收入（等同总产
出）分为劳动报酬（MPLx L）和资本报酬(MPKxK)：F(I<，L)=(MPK×K) - (MPL×L)。+
如果向每种要素支付其边际产量，那这些要素支付的总和等于总产出。换言之，规模收益不
变，利润最大化，以及竞争性共同意味着经济利润为零。一
实际GDP变动百分比-3%-2×失业率的变动，印如果失业率保持不变，实际GDP增长3%
左右。这种正常的增长率是由于人口增长、资本积累和技术进步引起的。失业率每上升一个
曼昆宏观经济学-课后答案-中文版
3、劳工统计局把经济中每个人分为三种类型：就业、失业以及不属于劳动力。一
失业率是失业者在劳动力中所占的百分比，其中劳动力为就业者和失业者之和。一
-I、奥肯定理是指失业与实际GDP之间的这种负相关关系。就业工人有助于生产物品与劳务，
而失业工人并非如此。失业率提高必定与实际GDP的减少相关。舆肯定理可以概括为等式：
济活动不完善的衡量。一旦男管家的工作成为他家务劳动的一部分，他的劳务就不再计入GDP。
这例子说明，GDP不包括任何在家里产出的价值。同样，GDP也不包括耐用品（汽车以及电冰箱
等）的估算租金和非法贸易等物品或劳务。一
_I、政府采购、投资、净出口、消费、投资一
6、(1)2000年名义GDP-10000000，2010年名义GDP-15200000，2010年实际GDP-IOOOOOOO
清模型无用。首先偷格并不总是呆滞的，最终价格要根据供求的变动而调整。市场出清模型
并不能描述每一种情况下的经济，但描述了经济缓慢地趋近了均衡。价格的伸缩性对研究我
们在几十年中所观察到的实际GDP增长这类长期问题是一个好的假设。
第二章宏观经济学数据
复习题
1、GDP既衡量经济中所有人的收入，又衡量对经济物品与劳务的总支出。
2010年GDP隐含的价格平减指数-1. 52，2010年(’PI-1.6一
(2)隐含的价格平减指数是帕氏指数，因为它是用一篮子可变物品计算的。CPI是拉斯派
尔指数，因为它是用一篮子固定物品计算的。由(1)中计算得2010年隐含的价格平减指数
是1.52，它表示物价从2000年到2010年上涨了5)0，o；而（1PI是1.6，它表示物价从2000年到2010
随着劳动力增加而递减。因此，实际工资下降。一
曼昆《经济学原理》答案DOC
曼昆《经济学原理》答案DOC 在当今社会，经济学已经成为了一门至关重要的学科，它影响着我们生活的方方面面，从个人的消费决策到国家的宏观政策。
而曼昆的《经济学原理》作为一本经典的经济学教材，被广泛地应用于教学和学习中。
对于许多学习者来说，寻找《经济学原理》的答案是理解和掌握这门学科的关键。
首先，我们需要明确什么是曼昆《经济学原理》。
这本书分为微观经济学和宏观经济学两个部分。
微观经济学主要研究个体经济单位的行为，如消费者、生产者和市场结构等；宏观经济学则关注整个经济的总体运行，包括经济增长、通货膨胀、失业率等宏观经济变量。
在微观经济学部分，一个重要的概念是供求关系。
供给和需求的相互作用决定了商品和服务的价格。
例如，当某种商品的需求增加而供给不变时，价格会上升；反之，如果供给增加而需求不变，价格则会下降。
这一原理在解释市场中各种商品的价格波动时非常有用。
另一个关键的概念是边际分析。
边际成本和边际收益的比较对于企业的决策至关重要。
如果边际收益大于边际成本，企业通常会选择增加生产或提供服务；反之，如果边际成本大于边际收益，企业可能会减少生产或服务。
消费者行为也是微观经济学的重要内容。
消费者在预算约束下追求效用最大化，他们会根据商品的价格和自身的偏好来做出购买决策。
在宏观经济学部分，经济增长是一个核心问题。
投资、技术进步和劳动力增长等因素都会影响经济的长期增长。
通货膨胀则是另一个重要的宏观经济现象，它会导致货币的购买力下降，对经济产生各种影响。
对于失业率的研究也是宏观经济学的一部分。
失业率的高低反映了经济的健康状况，政府通常会采取各种政策来降低失业率，促进就业。
那么，关于曼昆《经济学原理》的答案，我们可以从以下几个方面来探讨。
在学习过程中，课后的练习题和案例分析是检验对知识理解和掌握程度的重要方式。
对于这些问题的答案，我们需要运用书中所学到的原理和概念，结合实际情况进行分析和推理。
例如，在一道关于市场供求变化的练习题中，如果给出了某种商品的需求曲线和供给曲线的变动情况，我们需要判断价格和数量的变化方向。
曼昆宏观经济学-课后答案-中文版
3、劳工统计局把经济中每个人分为三种类型：就业、失业以及不属于劳动力。一
失业率是失业者在劳动力中所占的百分比，其中劳动力为就业者和失业者之和。一
-I、奥肯定理是指失ห้องสมุดไป่ตู้与实际GDP之间的这种负相关关系。就业工人有助于生产物品与劳务，
而失业工人并非如此。失业率提高必定与实际GDP的减少相关。舆肯定理可以概括为等式：
2010年GDP隐含的价格平减指数-1. 52，2010年(’PI-1.6一
(2)隐含的价格平减指数是帕氏指数，因为它是用一篮子可变物品计算的。CPI是拉斯派
尔指数，因为它是用一篮子固定物品计算的。由(1)中计算得2010年隐含的价格平减指数
是1.52，它表示物价从2000年到2010年上涨了5)0，o；而（1PI是1.6，它表示物价从2000年到2010
济活动不完善的衡量。一旦男管家的工作成为他家务劳动的一部分，他的劳务就不再计入GDP。
这例子说明，GDP不包括任何在家里产出的价值。同样，GDP也不包括耐用品（汽车以及电冰箱
等）的估算租金和非法贸易等物品或劳务。一
_I、政府采购、投资、净出口、消费、投资一
6、(1)2000年名义GDP-10000000，2010年名义GDP-15200000，2010年实际GDP-IOOOOOOO
GDP能同时衡量这两件事，是因为这两个量实际上是相同的：对整个经济来说，收入必
定等于支出。这个事实又来自于一个更有基本的事实：由于每一次交易都有一个买者和一个
卖者，所以，一个买者支出的每一美元必然成为一个卖者的一美元收入。
2、CPI衡量经济中物价总水平。它表示相对于某个基年一篮子物品与劳务价格的同样一篮
济学家建立模型有助于解释GDP、通货膨胀和失业这类经济变量。这些模型之所以有用是
曼昆经济学原理04-供给需求及市场力量
12
A
D1
20
Number of Cigarettes
Smoked per Day
Change in Quantity Demanded versus Change in Demand
Change in Demand
A shift in the demand curve, either to the left or right.
equal.”
The demand curve slopes downward because, ceteris paribus, lower prices
imply a greater quantity demanded!
Market Demand
Market demand refers to the sum of all individual demands for a particular good or service. Graphically, individual demand
Markets
Buyers determine demand.
Sellers determine supply.
Marcompetitive market is a market. . .
with many buyers and sellers.
Price of Ice-Cream Cone
$3.00
2.50
2.00
1.50
1.00
Consumer Income
Normal Good
Increase in demand
An increase in income...
0.50 01
D1
曼昆经济学原理第六版第4章 供给与需求的市场力量课后习题答案
圣才考研网 ——考研考博专业课辅导―中国第一品牌咨询 QQ：1224978229第2篇 第4章市场如何运行供给与需求的市场力量一、概念题 1．市场（market） 答： 市场指某种物品或劳务的买者与卖者组成的一个群体。
买者作为一个群体决定了一 种物品或劳务的需求，而卖者作为一个群体决定了一种物品或劳务的供给。
市场作为商品经济的范畴，具有三层含义：一是指商品交换的场所；二是指由商品供求 双方及其中介人之间， 围绕着体现各自利益的价格而展开激烈竞争所形成的各种经济关系总 和； 三是指调节社会经济运行的一种关系。
贯穿于这三层含义并能统一于市场这一范畴的核 心是商品交换，或者说是商品流通。
2．竞争市场（competitive market） 答： 竞争市场指有许多买者和卖者， 以至于每一个人对市场价格的影响都微不足道的市 场。
竞争市场一般指完全竞争市场。
完全竞争，又称为纯粹竞争，是指不存在任何阻碍和干 扰竞争因素的市场情况， 亦即没有任何垄断因素的市场结构。
完全竞争市场需要具备以下四 个条件：①市场上有大量的买者和卖者；②市场上每一个厂商提供的商品都是同质的；③所 有的资源具有完全的流动性；④信息是完全的。
3．需求量（quantity demanded） 答： 需求量是指消费者在一定时期内， 在各种可能的价格水平下愿意而且能够购买的商 品的数量。
根据定义，如果消费者对某种商品只有购买的欲望而没有购买的能力，就不能算 作是需求。
需求必须是既有购买欲望又有购买能力的有效需求。
影响商品需求的因素有:该 商品的价格、消费者收入、其他相关商品价格、消费者偏好和消费者对未来的预期等。
在其 他影响因素不变的条件下，需求量与价格的关系可用需求曲线来表示。
一般说来，随着商品 价格的提高，消费者消费商品的数量减少。
4．需求定理（law of demand） 答：需求定理是有关物品价格与需求量之间关系的定理。
该定理的内容是：在其他条件 不变的情况下， 某商品的需求量与价格之间成反方向变动， 即需求量随着商品本身价格的上 升而减少，随商品价格的下降而增加。
曼昆宏观经济学-课后答案-中文版
人的支付。转移支付是减少家庭可支配收入的税收的对立面，它增加家庭的可支配收入。例如对
老年人的社会保障支付、失业包厢以及退伍军人津贴，它不包括在GDP中。一
6、消费、投资、Βιβλιοθήκη 府购买决定经济产出的需求，而生产要素与生产函数袂定经济产出的供求。
济活动不完善的衡量。一旦男管家的工作成为他家务劳动的一部分，他的劳务就不再计入GDP。
这例子说明，GDP不包括任何在家里产出的价值。同样，GDP也不包括耐用品（汽车以及电冰箱
等）的估算租金和非法贸易等物品或劳务。一
_I、政府采购、投资、净出口、消费、投资一
6、(1)2000年名义GDP-10000000，2010年名义GDP-15200000，2010年实际GDP-IOOOOOOO
因此，一个竞争性的利润最大化的企业雇佣的劳动要到劳动边际产量等于实际工资时为
止。同样逻辑，企业租用的资本要到资本边际产量等于实际租赁价格为止。+-
3、如果所有生产要素增加相同百分比引起产出增加同样的百分比，生产要素有规模报酬不
变。比如，如果企业把资本和劳动都增加50%，产量也增加5 00.'0．那生产函数是规模报酬不
(5)当企业转变为少生产少排放污染的生产方法时，实际GDP可能下降。然而，经济檑利增加。
现在经济中可衡量的产出更少而清洁空气更多，清洁空气在市场上不可交易，因此无法显示可衡
量的GDP上升，但它是对人们有价值的物品一
(6)由于高中生从事不创造市场的物品与劳务的活动到可创造市场的物品与劳务活动，实际GDP
清模型无用。首先偷格并不总是呆滞的，最终价格要根据供求的变动而调整。市场出清模型
曼昆版经济学原理-参考答案-配插图表格
第一篇导言第一章经济学十大原理复习题1．列举三个你在生活中面临的重要权衡取舍的例子。
答：①大学毕业后，面临着是否继续深造的选择，选择继续上学攻读研究生学位，就意味着在今后三年中放弃参加工作、赚工资和积累社会经验的机会；②在学习内容上也面临着很重要的权衡取舍，如果学习《经济学》，就要减少学习英语或其他专业课的时间；③对于不多的生活费的分配同样面临权衡取舍，要多买书，就要减少在吃饭、买衣服等其他方面的开支。
2．看一场电影的机会成本是什么?答：看一场电影的机会成本是在看电影的时间里做其他事情所能获得的最大收益，例如：看书、打零工。
3．水是生活必需的。
一杯水的边际利益是大还是小呢?答：这要看这杯水是在什么样的情况下喝，如果这是一个人五分钟内喝下的第五杯水，那么他的边际利益很小，有可能为负；如果这是一个极度干渴的人喝下的第一杯水，那么他的边际利益将会极大。
4．为什么决策者应该考虑激励?答：因为人们会对激励做出反应。
如果政策改变了激励，它将使人们改变自己的行为，当决策者未能考虑到行为如何由于政策的原因而变化时，他们的政策往往会产生意想不到的效果。
5．为什么各国之间的贸易不像竞赛一样有赢家和输家呢?答：因为贸易使各国可以专门从事自己最擅长的活动，并从中享有更多的各种各样的物品与劳务。
通过贸易使每个国家可供消费的物质财富增加，经济状况变得更好。
因此，各个贸易国之间既是竞争对手，又是经济合作伙伴。
在公平的贸易中是“双赢”或者“多赢”的结果。
6．市场中的那只“看不见的手”在做什么呢?答：市场中那只“看不见的手”就是商品价格，价格反映商品自身的价值和社会成本，市场中的企业和家庭在作出买卖决策时都要关注价格。
因此，他们也会不自觉地考虑自己行为的(社会)收益和成本。
从而，这只“看不见的手”指引着千百万个体决策者在大多数情况下使社会福利趋向最大化。
7．解释市场失灵的两个主要原因，并各举出一个例子。
答：市场失灵的主要原因是外部性和市场势力。
曼昆《经济学原理》第6版-微观经济学分册-第4章-课后习题答案P92-P94.doc
第二篇市场如何运作第四章供给与需求的市场力量复习题1．什么是竞争市场?简单描述除了完全竞争市场之外的市场类型。
答：竞争市场是有许多买者与卖者，以至于每个人对市场价格的影响都微乎其微的市场。
除了完全竞争市场之外，还有垄断市场。
在这个市场上只有一个卖者，他决定价格。
这个卖者被称为垄断者。
还有寡头市场，在这个市场上有几个并不总是主动竞争的卖者，他们提供相似或相同的产品。
通常情况下，寡头们会尽力联合起来，避免激烈的竞争，收取较高的市场价格。
还有垄断竞争市场，这是一个有许多提供相似但不相同产品的企业的市场结构。
由于各自提供的产品不同，每个企业对产品的价格都有一定的影响力。
2．什么是需求表和需求曲线?它们如何相关联?为什么需求曲线向右下方倾斜?答：需求表是表示一种物品价格与需求量之间关系的表格，需求曲线是表示一种物品价格与需求量之间关系的图形。
需求曲线将需求表用图形的形式表现出来，需求表是需求曲线上若干个点的坐标的数字表格排列。
需求曲线向右下方倾斜是因为在其他条件不变的情况下，随着价格上升，需求量会减少。
3．消费者嗜好的变化引起了沿着需求曲线的变动，还是需求曲线的移动，价格的变化引起了沿着需求曲线的变动，还是需求曲线的移动?答：消费者嗜好的变化引起了需求曲线的移动，价格的变化引起了沿着需求曲线的变动。
4．Popeye的收入减少了，结果他买了更多的菠菜。
菠菜是低档物品，还是正常物品? Popeye菠菜的需求曲线是什么样的?答：菠菜对波匹来说是低档物品。
因为Popeye的收入减少了，他对菠菜的需求量反而增大。
波匹菠菜的需求曲线是向右下方倾斜的。
5．什么是供给表和供给曲线，它们如何关联?为什么供给曲线向石上方倾斜?答：供给表是表示一种物品价格与供给量之间关系的表格，供给曲线是表示一种物品价格与供给量之间关系的图形。
供给曲线是供给表的图形表示，供给表是供给曲线上点的坐标的数字排列。
因为在其他因素不变时，价格上升，供给量上升，所以供给曲线向右上方倾斜。
曼昆_微观经济学_原理_第五版_课后习题答案(修改)
第一章问题与应用4．你在篮球比赛的赌注中赢了100美元。
你可以选择现在花掉它或在利率为55%的银行中存一年。
现在花掉100美元的机会成本是什么呢?答：现在花掉100 美元的机会成本是在一年后得到105 美元的银行支付(利息+本金)。
7．社会保障制度为65岁以上的人提供收入。
如果一个社会保障的领取者决定去工作并赚一些钱，他(或她)所领到的社会保障津贴通常会减少。
A．提供社会保障如何影响人们在工作时的储蓄激励?答：社会保障的提供使人们退休以后仍可以获得收入，以保证生活。
因此，人们不用为不能工作时的生活费而发愁，人们在工作时期的储蓄就会减少。
B．收入提高时津贴减少的政策如何影响65岁以上的人的工作激励??答：这会使65 岁以上的人在工作中不再积极进取。
因为努力工作获得高收入反而会使得到的津贴减少，所以对65 岁以上的人的努力工作的激励减少了。
11．解释下列每一项政府活动的动机是关注平等还是关注效率。
在关注效率的情况下，讨论所涉及的市场失灵的类型。
A．对有线电视频道的价格进行管制。
答：这是关注效率，市场失灵的原因是市场势力的存在。
可能某地只有一家有线电视台，由于没有竞争者，有线电视台会向有线频道的消费者收取高出市场均衡价格的价格，这是垄断。
垄断市场不能使稀缺资源得到最有效的配置。
在这种情况下，规定有线电视频道的价格会提高市场效率。
B．向一些穷人提供可用来购买食物的消费券。
答：这是出于关注平等的动机，政府这样做是想把经济蛋糕更公平地分给每一个人。
C．在公共场所禁止抽烟。
答：这是出于关注效率的动机。
因为公共场所中的吸烟行为会污染空气，影响周围不吸烟者的身体健康，对社会产生了有害的外部性，而外部性正是市场失灵的一种情况，而这也正是政府在公共场所禁止吸烟的原因。
D．把美孚石油公司(它曾拥90%的炼油厂)分拆为几个较小的公司。
答：出于关注效率的动机，市场失灵是由于市场势力。
美孚石油公司在美国石油业中属于规模最大的公司之一，占有相当大的市场份额，很容易形成市场垄断。
曼昆微观经济学答案ch04
The Market Forces of Supply and DemandWHAT’S NEW IN THE THIRD EDITION:This chapter has been completely rearranged and rewritten.LEARNING OBJECTIVES:By the end of this chapter, students should understand:what a competitive market is.what determines the demand for a good in a competitive market.what determines the supply of a good in a competitive market.how supply and demand together set the price of a good and the quantity sold.the key role of prices in allocating scarce resources in market economies.CONTEXT AND PURPOSE:Chapter 4 is the first chapter in a three-chapter sequence that deals with supply and demand and how markets work. Chapter 4 shows how supply and demand for a good determines both the quantityproduced and the price at which the good sells. Chapter 5 will add precision to the discussion of supply and demand by addressing the concept of elasticity —the sensitivity of the quantity supplied and quantity demanded to changes in economic variables. Chapter 6 will address the impact of government policies on prices and quantities in markets.The purpose of Chapter 4 is to establish the model of supply and demand. The model of supply and demand is the foundation for the discussion for the remainder of this text. For this reason, time spent studying the concepts in this chapter will return benefits to your students throughout their study of economics. Many instructors would argue that this chapter is the most important chapter in the text.THE MARKET FORCES OF SUPPLY AND DEMAND52 Chapter 4/The Market Forces of Supply and DemandKEY POINTS:1.Economists use the model of supply and demand to analyze competitive markets. In a competitivemarket, there are many buyers and sellers, each of whom has little or no influence on the market price.2.The demand curve shows how the quantity of a good demanded depends on the price. According tothe law of demand, as the price of a good falls, the quantity demanded rises. Therefore, the demand curve slopes downward.3.In addition to price, other determinants of how much consumers want to buy include income, theprices of substitutes and complements, tastes, expectations, and the number of buyers. If one of these factors changes, the demand curve shifts.4.The supply curve shows how the quantity of a good supplied depends on the price. According to thelaw of supply, as the price of a good rises, the quantity supplied rises. Therefore, the supply curve slopes upward.5.In addition to price, other determinants of how much producers want to sell include input prices,technology, expectations, and the number of sellers. If one of these factors changes, the supply curve shifts.6.The intersection of the supply and demand curves determines the market equilibrium. At theequilibrium price, the quantity demanded equals the quantity supplied.7.The behavior of buyers and sellers naturally drives markets toward their equilibrium. When themarket price is above the equilibrium price, there is a surplus of the good, which causes the market price to fall. When the market price is below the equilibrium price, there is a shortage, which causes the market price to rise.8.To analyze how any event influences a market, we use the supply-and-demand diagram to examinehow the event affects equilibrium price and quantity. To do this we follow three steps. First, we decide whether the event shifts the supply curve or the demand curve (or both). Second, we decide which direction the curve shifts. Third, we compare the new equilibrium with the initial equilibrium.9.In market economies, prices are the signals that guide economic decisions and thereby allocatescarce resources. For every good in the economy, the price ensures that supply and demand are in balance. The equilibrium price then determines how much of the good buyers choose to purchase and how much sellers choose to produce.CHAPTER OUTLINE:I. Markets and CompetitionChapter 4/The Market Forces of Supply and Demand 53A. Definition of market: a group of buyers and sellers of a particular good orservice.B. Definition of competitive market: a market in which there are many buyers andmany sellers so that each has a negligible impact on the market price.C. Competition: Perfect and Otherwise1. Characteristics of a perfectly competitive market:a. The goods being offered for sale are all the same.b. The buyers and sellers are so numerous that none can influence themarket price.2. Because buyers and sellers must accept the market price as given, they are oftencalled "price takers."3. Not all goods are sold in a perfectly competitive market.a. A market with only one seller is called a monopoly market.b. A market with only a few sellers is called an oligopoly.c. A market with a large number of sellers, each selling a product that isslightly different from its competitors‘ products, is called monopolisticcompetition.D. We will start by studying perfect competition.II. DemandA. The Demand Curve: The Relationship between Price and Quantity Demanded1. Definition of quantity demanded: the amount of a good that buyers arewilling and able to purchase.2. One important determinant of quantity demanded is the price of the product.a. Quantity demanded is negatively related to price. This implies that thedemand curve is downward sloping.b. Definition of law of demand: the claim that, other things equal,the quantity demanded of a good falls when the price of thegood rises.54 Chapter 4/The Market Forces of Supply and Demand3. Definition of demand schedule: a table that shows the relationshipbetween the price of a good and the quantity demanded.4. Definition of demand curve: a graph of the relationship between theprice of a good and the quantity demanded. a. Price is generally drawn on the vertical axis.b.Quantity demanded is represented on the horizontal axis.Chapter 4/The Market Forces of Supply and Demand 55B. Market Demand Versus Individual Demand1.The market demand is the sum of all of the individual demands for a particular good or service.2.The demand curves are summed horizontally —meaning that the quantities demanded are added up for each level of price.3.The market demand curve shows how the total quantity demanded of a good varies with the price of the good, holding constant all other factors that affect how much consumers want to buy.C.Shifts in the Demand Curve1. The demand curve shows how much consumers want to buy at any price,holding constant the many other factors that influence buying decisions.2. If any of these other factors change, the demand curve will shift.a. An increase in demand can be represented by a shift of the demandcurve to the right.b.A decrease in demand can be represented by a shift of the demand curve to the left.3.Income56 Chapter 4/The Market Forces of Supply and Demanda.The relationship between income and quantity demanded depends on what type of good the product is.b.Definition of normal good: a good for which, other things equal, an increase in income leads to an increase in demand.c.Definition of inferior good: a good for which, other things equal, an increase in income leads to a decrease in demand.4. Prices of Related Goodsa.Definition of substitutes: two goods for which an increase in theprice of one good leads to an increase in the demand for the other.b.Definition of complements: two goods for which an increase in the price of one good leads to a decrease in the demand for the other.5. Tastes6.Expectationsa. Future Incomeb.Future Prices7. Number of BuyersD.Case Study: Two Ways to Reduce the Quantity of Smoking Demanded1.Public service announcements, mandatory health warnings on cigarette packages, and the prohibition of cigarette advertising on television are policies designed to reduce the demand for cigarettes (and shift the demand curve to the left). 2.Raising the price of cigarettes (through tobacco taxes) lowers the quantity of cigarettes demanded.Chapter 4/The Market Forces of Supply and Demand 57a. The demand curve does not shift in this case, however.b. An increase in the price of cigarettes can be shown by a movementalong the original demand curve.3. Studies have shown that a 10% increase in the price of cigarettes causes a 4%reduction in the quantity of cigarettes demanded. For teens a 10% increase inprice leads to a 12% drop in quantity demanded.4. Studies have also shown that a decrease in the price of cigarettes is associatedwith greater use of marijuana. Thus, it appears that tobacco and marijuana arecomplements.III. SupplyA. The Supply Curve: The Relationship between Price and Quantity Supplied1. Definition of quantity supplied: the amount of a good that sellers arewilling and able to sell.a. Quantity supplied is positively related to price.b. Definition of law of supply: the claim that, other things equal, thequantity supplied of a good rises when the price of the goodrises.2. Definition of supply schedule: a table that shows the relationshipbetween the price of a good and the quantity supplied.3. Definition of supply curve: a graph of the relationship between the priceof a good and the quantity supplied.58 Chapter 4/The Market Forces of Supply and DemandB.Market Supply Versus Individual Supply1. The market supply curve can be found by summing individual supply curves.2. Individual supply curves are summed horizontally at every price.3.The market supply curve shows how the total quantity supplied varies as the price of the good varies.Chapter 4/The Market Forces of Supply and Demand 59C. Shifts in the Supply Curve1. The supply curve shows how much producers offer for sale at any given price, holding constant all other factors that may influence producers‘ decisions about how much to sell.2. When any of these other factors change, the supply curve will shift.a. An increase in supply can be represented by a shift of the supply curve to the right.b.A decrease in supply can be represented by a shift of the supply curve to the left.3. Input Prices4.Technology5. Expectations6. Number of SellersIV. Supply and Demand Together A.Equilibrium 1. The point where the supply and demand curves intersect is called the market‘s equilibrium.2.Definition of equilibrium: a situation in which the price has reached the level where quantity supplied equals quantity demanded.60 Chapter 4/The Market Forces of Supply and DemandDefinition of equilibrium price: the price that balances quantity supplied and quantity demanded.4.The equilibrium price is often called the "market-clearing" price because both buyers and sellers are satisfied at this price.5.Definition of equilibrium quantity: the quantity supplied and the quantity demanded at the equilibrium price.6. If the actual market price is higher than the equilibrium price, there will be asurplus of the good.a. Definition of surplus: a situation in which quantity supplied isgreater than quantity demanded.b.To eliminate the surplus, producers will lower the price until the marketreaches equilibrium.7. If the actual price is lower than the equilibrium price, there will be a shortage ofthe good.a. Definition of shortage: a situation in which quantity demanded isgreater than quantity supplied.b.Sellers will respond to the shortage by raising the price of the good untilthe market reaches equilibrium. Array8. Definition of the law of supply and demand: the claim that the price ofany good adjusts to bring the supply and demand for that good intobalance.B.Three Steps to Analyzing Changes in Equilibrium1. Decide whether the event shifts the supply or demand curve (or perhaps both).2. Decide in which direction the curve shifts.3.Use the supply-and-demand diagram to see how the shift changes the equilibrium price and quantity.A.Example: A Change in Demand — the effect of hot weather on the market for ice cream.ALTERNATIVE CLASSROOM EXAMPLE:Go through these examples of events that would shift either the demand or supply of #2 lead pencils:▪ an increase in the income of consumers▪ an increase in the use of standardized exams (using opscan forms) ▪ a decrease in the price of graphite (used in the production of pencils) ▪ a decrease in the price of ink pens ▪ the start of a school year▪ new technology that lowers the cost of producing pencilsD.Shifts in Curves versus Movements Along Curves 1.A shift in the demand curve is called a "change in demand." A shift in the supply curve is called a "change in supply."2.A movement along a fixed demand curve is called a "change in quantity demanded." A movement along a fixed supply curve is called a "change in quantity supplied."E.Example: A Change in Supply — the effect of a hurricane that destroys part of the sugar-cane crop and drives up the price of sugar.F.In the News: Mother Nature Shifts the Supply Curve1.Newspaper articles about specific industries can give students practice understanding the things that affect supply and demand.2.This is an article from The New York Times that describes the effect of a freeze on the citrus market.G.Example: A Change in Both Supply and Demand —the effect of both hot weather and an earthquake which destroys several ice cream factories on the market for ice cream.H. Summary1. When an event shifts the supply or demand curve, we can examine the effectson the equilibrium price and quantity.2. Table 4 reports the end results of these shifts in supply and demand.V. Conclusion: How Prices Allocate Resources A. The model of supply and demand is a powerful tool for analyzing markets.B.Supply and demand together determine the price of the economy‘s goods and services. 1.These prices serve as signals that guide the allocation of scarce resources in the economy.2.Prices determine who produces each good and how much of each good is produced.SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes 1. A market is a group of buyers (who determine demand) and a group of sellers (who determinesupply) of a particular good or service. A competitive market is one in which there are many buyers and many sellers of an identical product so that each has a negligible impact on the market price.2. Here‘s an example of a demand schedule for pizza:The demand curve is graphed in Figure 1.Figure 1Examples of things that would shift the demand curve include changes in income, prices ofrelated goods like soda or hot dogs, tastes, expectations about future income or prices, and the number of buyers.A change in the price of pizza would not shift this demand curve; it would only lead us to movefrom one point to another along the same demand curve.3. Here is an example of a supply schedule for pizza:The supply curve is graphed in Figure 2.Figure 2Examples of things that would shift the supply curve include changes in prices of inputs liketomato sauce and cheese, changes in technology like more efficient pizza ovens or automaticdough makers, changes in expectations about the future price of pizza, or a change in thenumber of sellers.A change in the price of pizza would not shift this supply curve; it would only move from onepoint to another along the same supply curve.4. If the price of tomatoes rises, the supply curve for pizza shifts to the left because of theincreased price of an input into pizza production, but there is no effect on demand. The shift to the left of the supply curve causes the equilibrium price to rise and the equilibrium quantity todecline, as Figure 3 shows.If the price of hamburgers falls, the demand curve for pizza shifts to the left because the lower price of hamburgers will lead consumers to buy more hamburgers and less pizza, but there is no effect on supply. The shift to the left of the demand curve causes the equilibrium price to falland the equilibrium quantity to decline, as Figure 4 shows.Figure 3Questions for Review1. A competitive market is a market in which there are many buyers and many sellers of an identicalproduct so that each has a negligible impact on the market price. Other types of markets includemonopoly, in which there is only one seller, oligopoly, in which there are a few sellers that do notalways compete aggressively, and monopolistically competitive markets, in which there are many sellers, each offering a slightly different product.2. The quantity of a good that buyers demand is determined by the price of the good, income, theprices of related goods, tastes, expectations, and the number of buyers.3. The demand schedule is a table that shows the relationship between the price of a good and thequantity demanded. The demand curve is the downward-sloping line relating price and quantity demanded. The demand schedule and demand curve are related because the demand curve is simply a graph showing the points in the demand schedule.The demand curve slopes downward because of the law of demand—other things equal, whenthe price of a good rises, the quantity demanded of the good falls. People buy less of a goodwhen its price rises, both because they cannot afford to buy as much and because they switch to purchasing other goods.4. A change in consumers' tastes leads to a shift of the demand curve. A change in price leads to amovement along the demand curve.5. Since Popeye buys more spinach when his income falls, spinach is an inferior good for him.Since he buys more spinach, but the price of spinach is unchanged, his demand curve for spinach shifts out as a result of the decrease in his income.6. The quantity of a good that sellers supply is determined by the price of the good, input prices,technology, expectations, and the number of sellers.7. A supply schedule is a table showing the relationship between the price of a good and thequantity a producer is willing and able to supply. The supply curve is the upward-sloping linerelating price and quantity supplied. The supply schedule and the supply curve are relatedbecause the supply curve is simply a graph showing the points in the supply schedule.The supply curve slopes upward because when the price is high, suppliers' profits increase, sothey supply more output to the market. The result is the law of supply—other things equal,when the price of a good rises, the quantity supplied of the good also rises.8. A change in producers' technology leads to a shift in the supply curve. A change in price leads toa movement along the supply curve.9. The equilibrium of a market is the point at which the quantity demanded is equal to quantitysupplied. If the price is above the equilibrium price, sellers want to sell more than buyers want to buy, so there is a surplus. Sellers try to increase their sales by cutting prices. That continues until they reach the equilibrium price. If the price is below the equilibrium price, buyers want to buy more than sellers want to sell, so there is a shortage. Sellers can raise their price withoutlosing customers. That continues until they reach the equilibrium price.10. When the price of beer rises, the demand for pizza declines, because beer and pizza arecomplements and people want to buy less beer. When we say the demand for pizza declines, we mean that the demand curve for pizza shifts to the left as in Figure 5. The supply curve for pizza is not affected. With a shift to the left in the demand curve, the equilibrium price and quantityboth decline, as the figure shows. Thus the quantity of pizza supplied and demanded both fall.In sum, supply is unchanged, demand is decreased, quantity supplied declines, quantitydemanded declines, and the price falls.Figure 511. Prices play a vital role in market economies because they bring markets into equilibrium. If theprice is different from its equilibrium level, quantity supplied and quantity demanded are notequal. The resulting surplus or shortage leads suppliers to adjust the price until equilibrium is restored. Prices thus serve as signals that guide economic decisions and allocate scarceresources.Problems and Applications1. a. Cold weather damages the orange crop, reducing the supply of oranges. This can beseen in Figure 6 as a shift to the left in the supply curve for oranges. The newequilibrium price is higher than the old equilibrium price.Figure 6b. People often travel to the Caribbean from New England to escape cold weather, sodemand for Caribbean hotel rooms is high in the winter. In the summer, fewer peopletravel to the Caribbean, since northern climes are more pleasant. The result, as shownin Figure 7, is a shift to the left in the demand curve. The equilibrium price of Caribbeanhotel rooms is thus lower in the summer than in the winter, as the figure shows.Figure 7c. When a war breaks out in the Middle East, many markets are affected. Since much oilproduction takes place there, the war disrupts oil supplies, shifting the supply curve forgasoline to the left, as shown in Figure 8. The result is a rise in the equilibrium price ofgasoline. With a higher price for gasoline, the cost of operating a gas-guzzlingautomobile, like a Cadillac, will increase. As a result, the demand for used Cadillacs willdecline, as people in the market for cars will not find Cadillacs as attractive. In addition,some people who already own Cadillacs will try to sell them. The result is that thedemand curve for used Cadillacs shifts to the left, while the supply curve shifts to theright, as shown in Figure 9. The result is a decline in the equilibrium price of usedCadillacs.Figure 8 Figure 92. The statement that "an increase in the demand for notebooks raises the quantity of notebooksdemanded, but not the quantity supplied," in general, is false. As Figure 10 shows, the increase in demand for notebooks results in an increased quantity supplied. The only way the statement would be true is if the supply curve was a vertical line, as shown in Figure 11.Figure 10Figure 113. a. If people decide to have more children (a change in tastes), they will want larger vehiclesfor hauling their kids around, so the demand for minivans will increase. Supply won't beaffected. The result is a rise in both price and quantity, as Figure 12 shows.Figure 12b. If a strike by steelworkers raises steel prices, the cost of producing a minivan rises (a risein input prices), so the supply of minivans decreases. Demand won't be affected. Theresult is a rise in the price of minivans and a decline in the quantity, as Figure 13 shows.Figure 13c. The development of new automated machinery for the production of minivans is animprovement in technology. The reduction in firms' costs results in an increase in supply.Demand isn't affected. The result is a decline in the price of minivans and an increase inthe quantity, as Figure 14 shows.Figure 14d. The rise in the price of sport utility vehicles affects minivan demand because sport utilityvehicles are substitutes for minivans (that is, there is a rise in the price of a related good).The result is an increase in demand for minivans. Supply is not affected. In equilibrium,the price and quantity of minivans both rise, as Figure 12 shows.e. The reduction in peoples' wealth caused by a stock-market crash reduces their income,leading to a reduction in the demand for minivans, since minivans are likely a normalgood. Supply isn‘t affected. As a result, both price and quantity decline, as Figure 15shows.Figure 154. Technological advances that reduce the cost of producing computer chips represent a decline inan input price for producing a computer. The result is a shift to the right in the supply ofcomputers, as shown in Figure 16. The equilibrium price falls and the equilibrium quantity rises, as the figure shows.Figure 16Since computer software is a complement to computers, the lower equilibrium price of computers increases the demand for software. As Figure 17 shows, the result is a rise in both theequilibrium price and quantity of software.Figure 17Since typewriters are substitutes for computers, the lower equilibrium price of computers reduces the demand for typewriters. As Figure 18 shows, the result is a decline in both the equilibriumprice and quantity of typewriters.Figure 185. a. When a hurricane in South Carolina damages the cotton crop, it raises input prices forproducing sweatshirts. As a result, the supply of sweatshirts shifts to the left, as shownin Figure 19. The new equilibrium has a higher price and lower quantity of sweatshirts.Figure 19b. A decline in the price of leather jackets leads more people to buy leather jackets,reducing the demand for sweatshirts. The result, shown in Figure 20, is a decline in both the equilibrium price and quantity of sweatshirts.Figure 20c. The effects of colleges requiring students to engage in morning calisthenics inappropriate attire raises the demand for sweatshirts, as shown in Figure 21. The result is an increase in both the equilibrium price and quantity of sweatshirts.Figure 21d. The invention of new knitting machines increases the supply of sweatshirts. As Figure 22shows, the result is a reduction in the equilibrium price and an increase in the equilibriumquantity of sweatshirts.Figure 226. A temporarily high birth rate in the year 2005 leads to opposite effects on the price of babysittingservices in the years 2010 and 2020. In the year 2010, there are more 5-year olds who needsitters, so the demand for babysitting services rises, as shown in Figure 23. The result is ahigher price for babysitting services in 2010. However, in the year 2020, the increased number of 15-year olds shifts the supply of babysitting services to the right, as shown in Figure 24. The result is a decline in the price of babysitting services.Figure 23 Figure 247. Since ketchup is a complement for hot dogs, when the price of hot dogs rises, the quantitydemanded of hot dogs falls, thus reducing the demand for ketchup, causing both price andquantity of ketchup to fall. Since the quantity of ketchup falls, the demand for tomatoes byketchup producers falls, so both price and quantity of tomatoes fall. When the price of tomatoes falls, producers of tomato juice face lower input prices, so the supply curve for tomato juice shifts out, causing the price of tomato juice to fall and the quantity of tomato juice to rise. The fall in the price of tomato juice causes people to substitute tomato juice for orange juice, so thedemand for orange juice declines, causing the price and quantity of orange juice to fall. Now you can see clearly why a rise in the price of hot dogs leads to a fall in price of orange juice!Figure 258. a. Cigars and chewing tobacco are substitutes for cigarettes, since a higher price forcigarettes would increase the demand for cigars and chewing tobacco.b. An increase in the tax on cigarettes leads to increased demand for cigars and chewingtobacco. The result, as shown in Figure 25 for cigars, is a rise in both the equilibriumprice and quantity of cigars and chewing tobacco.c. The results in part (b) showed that a tax on cigarettes leads people to substitute cigarsand chewing tobacco for cigarettes when the tax on cigarettes rises. To reduce totaltobacco usage, policymakers might also want to increase the tax on cigars and chewingtobacco, or pursue some type of public education program.9. Quantity supplied equals quantity demanded at a price of $6 and quantity of 81 pizzas (Figure26). If price were greater than $6, quantity supplied would exceed quantity demanded, sosuppliers would reduce their price to gain sales. If price were less than $6, quantity demandedwould exceed quantity supplied, so suppliers could raise their price without losing sales. In both cases, the price would continue to adjust until it reached $6, the only price at which there isneither a surplus nor a shortage.。
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Problems and Applications1. a. Cold weather damages the orange crop, reducing the supply of oranges. Thiscan be seen in Figure 4-6 as a shift to the left in the supply curve for oranges.The new equilibrium price is higher than the old equilibrium price.Figure 4-6b. People often travel to the Caribbean from New England to escape cold weather,so demand for Caribbean hotel rooms is high in the winter. In the summer,fewer people travel to the Caribbean, since northern climes are more pleasant.The result, as shown in Figure 4-7, is a shift to the left in the demand curve.The equilibrium price of Caribbean hotel rooms is thus lower in the summerthan in the winter, as the figure shows.Figure 4-7c. When a war breaks out in the Middle East, many markets are affected. Sincemuch oil production takes place there, the war disrupts oil supplies,shifting the supply curve for gasoline to the left, as shown in Figure 4-8.The result is a rise in the equilibrium price of gasoline. With a higherprice for gasoline, the cost of operating a gas-guzzling automobile, likea Cadillac, will increase. As a result, the demand for used Cadillacs willdecline, as people in the market for cars won't find Cadillacs as attractive.In addition, some people who already own Cadillacs will try to sell them.The result is that the demand curve for used Cadillacs shifts to the left,while the supply curve shifts to the right, as shown in Figure 4-9. Theresult is a decline in the equilibrium price of used Cadillacs.Figure 4-8Figure 4-92. The statement that "an increase in the demand for notebooks raises the quantity ofnotebooks demanded, but not the quantity supplied" is false, in general. As Figure 4-10 shows, the increase in demand for notebooks results in an increased quantity supplied. The only way the statement would be true is if the supply curve were perfectly inelastic, as shown in Figure 4-11.Figure 4-10Figure 4-113. a. If people decide to have more children (a change in tastes), they'll wantlarger vehicles for hauling their kids around, so the demand for minivanswill increase. Supply won't be affected. The result is a rise in both priceand quantity, as Figure 4-12 shows.Figure 4-12Figure 4-13b. If a strike by steelworkers raises steel prices, the costs of producing aminivan rise (a rise in input prices), so the supply of minivans decreases.Demand won't be affected. The result is a rise in the price of minivans anda decline in the quantity, as Figure 4-13 shows.c. The development of new automated machinery for the production of minivansis an improvement in technology. The reduction in firms' costs results inan increase in supply. Demand isn't affected. The result is a decline inthe price of minivans and an increase in the quantity, as Figure 4-14 shows.Figure 4-14Figure 4-15d. The rise in the price of station wagons affects minivan demand because stationwagons are substitutes for minivans (that is, there's a rise in the priceof a related good). The result is an increase in demand for minivans.Supply isn't affected. In equilibrium, the price and quantity of minivansboth rise, as Figure 4-12 shows.e. The reduction in peoples' wealth caused by a stock-market crash reduces theirincome, leading to a reduction in the demand for minivans, since minivansare a normal good. Supply isn’t affected. As a result, both price andquantity decline, as Figure 4-15 shows.4. Technological advances that reduce the cost of producing computer chips representa decline in an input price for producing a computer. The result is a shift to theright in the supply of computers, as shown in Figure 4-16. The equilibrium price falls and the equilibrium quantity rises, as the figure shows.Figure 4-16Figure 4-17Since computer software is a complement to computers, the increased equilibrium quantity of computers increases the demand for software. As Figure 4-17 shows, the result is a rise in both the equilibrium price and quantity of software.Since typewriters are substitutes for computers, the increased equilibrium quantity of computers reduces the demand for typewriters. As Figure 4-18 shows, the result is a decline in both the equilibrium price and quantity of typewriters.Figure 4-185. a. When a hurricane in South Carolina damages the cotton crop, it raises inputprices for producing sweatshirts. As a result, the supply of sweatshirtsshifts to the left, as shown in Figure 4-19. The new equilibrium has a higherprice and lower quantity of sweatshirts.Figure 4-19b. A decline in the price of leather jackets leads more people to buy leatherjackets, reducing the demand for sweatshirts. The result, shown in Figure4-20, is a decline in both the equilibrium price and quantity of sweatshirts.Figure 4-20c. The effects of colleges requiring students to engage in morning calisthenicsin appropriate attire raises the demand for sweatshirts, as shown in Figure4-21. The result is an increase in both the equilibrium price and quantityof sweatshirts.Figure 4-21d. The invention of new knitting machines increases the supply of sweatshirts.As Figure 4-22 shows, the result is a reduction in the equilibrium price andan increase in the equilibrium quantity of sweatshirts.Figure 4-226. A temporarily high birth rate in the year 2005 leads to opposite effects on the priceof babysitting services in the years 2010 and 2020. In the year 2010, there are more 5-year olds who need sitters, so the demand for babysitting services rises, as shown in Figure 4-23. The result is a higher price for babysitting services in 2010. However, in the year 2020, the increased number of 15-year olds shifts the supply of babysitting services to the right, as shown in Figure 4-24. The result is a decline in the price of babysitting services.Figure 4-23Figure 4-247. Since ketchup is a complement for hot dogs, when the price of hot dogs rises, thequantity demanded of hot dogs falls, thus reducing the demand for ketchup, causing both price and quantity of ketchup to fall. Since the quantity of ketchup falls, the demand for tomatoes by ketchup producers falls, so both price and quantity of tomatoes fall. When the price of tomatoes falls, producers of tomato juice face lower input prices, so the supply curve for tomato juice shifts down, causing the price of tomato juice to fall and the quantity of tomato juice to rise. The fall in the price of tomato juice causes people to substitute tomato juice for orange juice, so the demand for orange juice declines, causing the price and quantity of orange juice to fall. Now you can see clearly why a rise in the price of hot dogs leads to a fall in price of orange juice!Figure 4-258. a. Cigars and chewing tobacco are substitutes for cigarettes, since a higherprice for cigarettes would increase demand for cigars and chewing tobacco.b. An increase in the tax on cigarettes leads to increased demand for cigarsand chewing tobacco. The result, as shown in Figure 4-25 for cigars, is arise in both the equilibrium price and quantity of cigars and chewing tobacco.c. The results in part (b) showed that a tax on cigarettes leads people tosubstitute cigars and chewing tobacco for cigarettes when the tax oncigarettes rises. To reduce total tobacco usage, policymakers might alsowant to increase the tax on cigars and chewing tobacco, or pursue some typeof public education program.9. Quantity supplied equals quantity demanded at a price of $6 and quantity of 81 pizzas(Figure 4-26). If price were greater than $6, quantity supplied would exceedquantity demanded, so suppliers would reduce their price to gain sales. If pricewere less than $6, quantity demanded would exceed quantity supplied, so supplierscould raise their price without losing sales. In both cases, the price wouldcontinue to adjust until it reached $6, the only price at which there's neithersurplus nor shortage.Figure 4-2610. a. If the price of flour falls, since flour is an ingredient in bagels, the supplycurve for bagels would shift to the right. The result, shown in Figure 4-27,would be a fall in the price of bagels and a rise in the equilibrium quantityof bagels.Since cream cheese is a complement to bagels, the rise in quantity demandedof bagels increases the demand for cream cheese, as shown in Figure 4-28.The result is a rise in both the equilibrium price and quantity of cream cheese.So, a fall in the price of flour indeed raises both the equilibrium priceof cream cheese and the equilibrium quantity of bagels.Figure 4-27Figure 4-28What happens if the price of milk falls? Since milk is an ingredient in cream cheese, the fall in the price of milk leads to an increase in the supply of cream cheese. This leads to a decrease in the price of cream cheese (Figure 4-29), rather than a rise in the price of cream cheese. So a fall in the price of milk couldn't have been responsible for the pattern observed.Figure 4-29Figure 4-30b. In part (a), we found that a fall in the price of flour led to a rise in theprice of cream cheese and a rise in the equilibrium quantity of bagels. Ifthe price of flour rose, the opposite would be true; it would lead to a fallin the price of cream cheese and a fall in the equilibrium quantity of bagels.Since the question says the equilibrium price of cream cheese has risen, itcouldn't have been caused by a rise in the price of flour.What happens if the price of milk rises? From part (a), we found that a fallin the price of milk caused a decline in the price of cream cheese, so a risein the price of milk would cause a rise in the price of cream cheese. Since bagels and cream cheese are complements, the rise in the price of cream cheese would reduce the demand for bagels, as Figure 4-30 shows. The result is a decline in the equilibrium quantity of bagels. So a rise in the price of milk does cause both a rise in the price of cream cheese and a decline in the equilibrium quantity of bagels.11. a. As Figure 4-31 shows, the supply curve is vertical. The constant supplymakes sense because the basketball arena has a fixed number of seats no matterwhat the price.Figure 4-31b. Quantity supplied equals quantity demanded at a price of $8. The equilibriumquantity is 8,000 tickets.c.Price Quantity Demanded Quantity Supplied$ 4 14,0008,0008 11,0008,000128,0008,000165,0008,000202,0008,000The new equilibrium price will be $12, which equates quantity demanded toquantity supplied. The equilibrium quantity is 8,000 tickets.12. The executives are confusing changes in demand with changes in quantity demanded.Figure 4-32 shows the demand curve prior to the marketing campaign (D1), and after the campaign (D2). The marketing campaign increased the demand for champagne, as shown, leading to a higher equilibrium price and quantity. The influence of the higher price on demand is already reflected in the outcome. It's impossible for the scenario outlined by the executives to occur.Figure 4-32（注：可编辑下载，若有不当之处，请指正，谢谢!）。