曼昆微观经济学第四章课后答案
微观经济学原理曼昆英文第四章
Markets and Competition
▪ A market is a group of buyers and sellers of a
particular product.
▪ A competitive market is one with many buyers
and sellers, each has a negligible effect on price.
quantities demanded by all buyers at each price.
▪ Suppose Helen and Ken are the only two buyers in
the Latte market. (Qd = quantity demanded)
Price Helen’s Qd Ken’s Qd
14
Demand Curve Shifters: Expectations ▪ Expectations affect consumers’ buying decisions. ▪ Examples:
▪ If people expect their incomes to rise,
their demand for meals at expensive restaurants may increase now.
11
Demand Curve Shifters: Prices of Related Goods
▪ Two goods are substitutes if
an increase in the price of one causes an increase in demand for the other.
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。
微观经济学第四章习题答案完整版
微观经济学第四章习题答案HEN system office room 【HEN16H-HENS2AHENS8Q8-HENH1688】第四章生产论1. 下面(表4—1)是一张一种可变生产要素的短期生产函数的产量表：可变要素的数量可变要素的总产量可变要素的平均产量可变要素的边际产量122103244125606677080963(2)该生产函数是否表现出边际报酬递减如果是，是从第几单位的可变要素投入量开始的解答：(1)利用短期生产的总产量(TP)、平均产量(AP)和边际产量(MP)之间的关系，可以完成对该表的填空，其结果如表4—2所示：可变要素的数量可变要素的总产量可变要素的平均产量可变要素的边际产量1222212610324812448122456012126661167701048708\f(34)09637－7高点以后开始逐步下降的这样一种普遍的生产现象。
本题的生产函数表现出边际报酬递减的现象，具体地说，由表4—2可见，当可变要素的投入量从第4单位增加到第5单位时，该要素的边际产量由原来的24下降为12。
2. 用图说明短期生产函数Q＝f(L，eq \o(K,\s\up6(－)))的TPL曲线、APL 曲线和MPL曲线的特征及其相互之间的关系。
解答：短期生产函数的TPL曲线、APL曲线和MPL曲线的综合图如图4—1所示。
图4—1由图4—1可见，在短期生产的边际报酬递减规律的作用下，MPL曲线呈现出先上升达到最高点A以后又下降的趋势。
从边际报酬递减规律决定的MPL曲线出发，可以方便地推导出TPL 曲线和APL曲线，并掌握它们各自的特征及相互之间的关系。
关于TPL 曲线。
由于MPL＝eq \f(d TP L,d L)，所以，当MP L＞0时，TP L曲线是上升的；当MPL ＜0时，TPL曲线是下降的；而当MPL＝0时，TPL曲线达最高点。
换言之，在L＝L3时，MPL曲线达到零值的B点与TPL曲线达到最大值的B′点是相互对应的。
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.。
微观经济学原理曼昆英文第四章讲解学习
?Suppose Helen and Ken are the only two buyers in
the Latte market. (Qd = quantity demanded)
Price Helen's Qd Ken's Qd
?In a perfectly competitive market: ?All goods exactly the same ?Buyers & sellers so numerous that no one can
affect market price – each is a “price taker ”
0
Q
5 10 15 20 25
P
$0.00 1.00 2.00 3.00 4.00 5.00 6.00
Qd (Market)
24 21 18 15 12 9 6
THE MARKET FORCES OF SUPPLY AND DEMAND
7
Demand Curve Shifters
?The demand curve shows how price affects
a good and the quantity sold?
?How do changes in the factors that affect demand
or supply affect the market price and quantity of a good?
?How do markets allocate resources?
THE MARKET FORCES OF SUPPLY AND DEMAND
曼昆微观经济学原理第五版课后习题答案
问题与应用1．描写下列每种情况所面临的权衡取舍：A．一个家庭决定是否买一辆新车。
答：如果买新车就要减少家庭其他方面的开支，如：外出旅行，购置新家具；如果不买新车就享受不到驾驶新车外出的方便和舒适。
B．国会议员决定对国家公园支出多少。
答：对国家公园的支出数额大，国家公园的条件可以得到改善，环境会得到更好的保护。
但同时，政府可用于交通、邮电等其他公共事业的支出就会减少。
C．一个公司总裁决定是否新开一家工厂。
答：开一家新厂可以扩大企业规模，生产更多的产品。
但可能用于企业研发的资金就少了。
这样，企业开发新产品、利用新技术的进度可能会减慢。
D．一个教授决定用多少时间备课。
0答：教授若将大部分时间用于自己研究，可能会出更多成果，但备课时间减少影响学生授课质量。
E．一个刚大学毕业的学生决定是否去读研究生。
答：毕业后参加工作，可即刻获取工资收入；但继续读研究生，能接受更多知识和未来更高收益。
2．你正想决定是否去度假。
度假的大部分成本((机票、旅馆、放弃的工资))都用美元来衡量，但度假的收益是心理的。
你将如何比较收益与成本呢??答：这种心理上的收益可以用是否达到既定目标来衡量。
对于这个行动前就会作出的既定目标，我们一定有一个为实现目标而愿意承担的成本范围。
在这个可以承受的成本范围内，度假如果满足了既定目标，如：放松身心、恢复体力等等，那么，就可以说这次度假的收益至少不小于它的成本。
3．你正计划用星期六去从事业余工作，但一个朋友请你去滑雪。
去滑雪的真实成本是什么？现在假设你已计划这天在图书馆学习，这种情况下去滑雪的成本是什么？请解释之。
答：去滑雪的真实成本是周六打工所能赚到的工资，我本可以利用这段时间去工作。
如果我本计划这天在图书馆学习，那么去滑雪的成本是在这段时间里我可以获得的知识。
微观经济学第四章课后练习答案
1、什么是欲望和效用？马斯洛把人的欲望分为哪五个层次？效用和使用价值的关系.答：1）欲望是一种缺乏的感觉与求得满足的愿望。
这也就是说,欲望是不足之感与求足之愿的统一,两者缺一都不能称为欲望。
2)效用是从消费某种物品中所得到的满足程度.3)马斯洛把人的欲望分为五个层次：第一,基本生理的需要,这是人类最基本的欲望；第二，安全的需要;第三，归属和爱的需要；第四，尊重的需要,这是人更高层次的社会需要；第五，自我实现的需要，这是人最高层次的欲望。
2、基数效用论和序数效用论的基本观点是什么？它们各采用何种分析方法？答：1）基数效用论基本观点是：效用是可以用计量并加总求和的，效用的大小是可以用基数（1，2，3…）来表示，正如长度单位可以用米来表示一样.2）序数效用论是为了弥补基数效用论的缺点而提出来的另一种研究消费者行为的理论。
其基本观点是：效用作为一种心理现象无法计量,也不能加总求和，只能表示出满足程度的高低与顺序，因此，效用只能用序数(第一、第二、第三…）来表示。
3）基数效用论采用的是边际效用分析法；序数效用论采用的是无差异曲线分析法。
3、什么叫“边际"?总效用和边际效用的关系如何？答：1)边际的含义是增量，指自变量增加1单位所引起的因变量的增加量。
2）总效用是指从消费一定量某种物品中所得到的总满足程度;边际效用是指某种物品的消费量每增加1单位所增加的满足程度.消费量变动做引起的效用的变动即位边际效用。
当边际效用为正数时，总效用是增加的；但边际效用为零时，总效用达到最大；当边际效用为负数时,总效用减少。
4、什么是边际效用递减规律？边际效用为什么递减？答：1）随着消费者对某种物品消费量的增加，他从该物品连续增加的消费单位中所得到的边际效用是递减的，这就被称为边际效用递减规律。
2）认为边际效用递减规律成立的学派，用两个理由来支持他们的论断.一是从人的生理和心理的角度来进行解释，认为随着相同消费品的连续增加，从每一单位消费品中所感受到的满足程度和对重复刺激的反应程度是递减的.二是从商品的多用途的角度来进行解释,认为消费者总是将第一单位的消费品用在最重要的用途上,第二单位的消费品用在次重要的用途上，如此等等.这样，消费品的边际效用，就随消费品的用途重要性的递减而递减。
微观经济学课后答案第四章
， 因此， 当 1 ， ，生产函数为规
生产函数为规模报酬递增；当 模报酬不变；当
1
1
，生产函数为规模报酬递减。
9、已知生产函数为Q=AL1/3K2/3 (1)在长期的生产中，该生产函数的规模报酬属于哪一类型？ (2)在短期生产中，该生产函数是否受边际报酬递减规律的支配
解：(1)
f ( L , K ) 0 1 ( L K )
1/2
2 K 3 L
该生产函数表现出规模报酬不变的特征当且仅当
f ( L , K ) f ( L , K )
对于任意的 1 。 2 1/2 即 0 1 ( L K ) 2 K 3 L
0 1 ( L K ) 0 0
1/2 故当且仅当 0 0 ，即 f ( L , K ) 1 ( L K ) 2 K 3 L 时，该生产函数 表现出规模报酬不变的特征。
1/2
2 K 3 L
注：本题去掉“规模报酬不变的情况下”，结论仍然成立。
6、假设某厂商的短期生产函数为 Q
35 L 8 L L
2
3
。
求：(1)该企业的平均产量函数和边际产量函数。 (2)如果企业使用的生产要素的数量 L=6， 是否处于短期生产的合理区间？ 为什么？ 解： (1)平均产量函数 A P
L
Q / L 35 8 L L
2
，
2
边际产量函数 M P (2)当 A P
K
2/3
Q L
2
AL
5 / 3
K
2/3
0
因此，该生产函数受边际报酬递减规律的支配。
曼昆《经济学原理(微观经济学分册)》(第6版)课后习题详解(第4章--供给与需求的市场力量)
曼昆《经济学原理（微观经济学分册）》（第6版）第2篇市场如何运行第4章供给与需求的市场力量课后习题详解跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。
以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。
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。
经济学基础曼昆课后习题答案
经济学基础曼昆课后习题答案The pony was revised in January 2021第一章经济学十大原理一、为每个关键术语选择一个定义关键术语定义--------------稀缺性 1、在社会成员中平等地分配利益的特征--------------经济学 2、市场不能有效的配置资源的状况--------------效率 3、有限的资源和无限的欲望--------------平等 4、一个工人一小时所生产的物品与劳务量--------------理性 5、市场上只有一个买者的情况--------------机会成本 6、利己的市场参与者可以不知不觉的使整体社会福利最大化的原理--------------边际变动 7、社会从其稀缺资源中得到最多东西的特性--------------激励 8、社会和企业在市场上的相互交易决定资源配置的经济--------------市场经济 9、经济活动的波动--------------产权 10、当一个人的行为对旁观者有影响时的情况--------------“看不见的手” 11、物价总水平的上升--------------市场失灵 12、对现行计划的增量调整--------------外部性 13、研究社会如何管理其稀缺资源--------------市场势力 14、得到某种东西所放弃的东西--------------垄断 15、一个人或一群人不适当的影响市场价格的能力--------------生产率 16、某种引起人行动的东西--------------通货膨胀 17、一个人拥有并使用稀缺资源的能力--------------经济周期 18、为了达到目标而尽可能系统性的做到最好二、判断正误--------------1、当政府用税收和福利再分配收入时，经济变得更有效率。
-------------2、当经济学家说“天下没有免费的午餐”时，他们是指所有经济决策都涉及权衡取舍。
曼昆微观经济学答案
第四章复习题1．在索洛模型中，更高的储蓄率将导致在稳定状态时有更高的资本存量，从而导致更高的经济产出。
反之，亦然。
如果增加储蓄率将增加稳定状态时的资本存量，增加新的稳定状态的经济产出，从而导致经济增长。
但是，达到稳定状态后，经济将不再增长。
2．这个问题的前提在于经济决策者更关心的整个社会的福利水平，而不是关注最终的产出水平。
因为，在尽可能简单的情况下，社会福利水平与消费量相关，所以，最大化社会福利水平问题就转化为一个消费量最大化问题。
而在黄金规则下，意味着达到稳定状态时，有最大的消费量。
因此，决策者会选择黄金规则的资本水平。
3．应该说，决策者对这两种情况都可能选择，只是看本国情况的不同而定。
因为：无论经济从高于还是低于黄金规则资本存量开始，则达到的新稳定状态的消费水平都将高于最初的稳定状态。
但如果经济从高于黄金规则资本存量开始，则意味着当期的消费水平会上升，此后逐步下降；而如果经济从低于黄金规则资本存量开始，则意味着可能要减少当期的消费水平以获得远期更高的消费水平。
如此看来，如果不选择黄金规则资本存量，则各期的消费水平会有所不同，也就可能造成不同世代的人的福利水平不同。
4．在一定的储蓄率下，人口增长率越高，则稳定状态资本越低，导致的产出水平也越低；反之，稳定状态资本越高，产出水平也就越高。
因此，人口增长率将影响稳定状态产出水平的高低，从而影响经济增长率。
可以通过改变储蓄率来改变经济增长率。
比如：要达到一定的经济增长率，如果人口增长率高，则要求更高的储蓄率；人口增长率低，储蓄率则较低。
问题与应用1．a）Y = F(K, L) = K1/2L1/2，将投入要素都变成原来的z倍，上式变为：Y = F(z K, z L) = z K1/2L1/2，因此，该生产函数的规模收益不变。
b）Y = F(K, L) = K1/2L1/2Y/L = F(K, L)/L = K1/2L1/2/L=(K/L)1/2即：y = f (k) = k1/2c) 在稳定状态下，资本存量不再发生变动。
微观经济学原理曼昆英文第四章
affect market price – each is a “price taker”
▪ Law of demand: the claim that the quantity
demanded of a good falls when the price of the good rises, other things equal
3
The Demand Schedule
▪ Demand schedule:
8
Demand Curve Shifters: # of Buyers ▪ Increase in # of buyers
0
Price Quantity of of lattes
lattes demanded
$0.00 16
1.00
14
2.00
12
3.00
10
4.00
8
5.00
6
6.00
4
Quantity
5
10
15 of Lattes
5
Market Demand versus Individual Demand ▪ The quantity demanded in the market is the sum of the
▪ These “other things” are non-price determinants
of demand (i.e., things that determine buyers’ demand for a good, other than the good’s price).
微观经济学第四章课后习题答案
JIUJIANG UNIVERSITY《微观经济学》2011-2012学年第二学期期中考试类别习题分析英文题目REVIEW QUESTIONS ANDPROBLES院系商学院专业金融学姓名邹俊倩班级 A1143学号 ***********演讲日期：第 7 周星期二Chapter 4 ElasticityREVIEW QUESTIONS1.Why does a consumer’s price elasticity of demand for a gooddepend on the fraction of the consumer’s income spent on that good ?The budget share is one of the determinnation of price elasticity of demand .Because the lager the share of your budget get an item accounts for,the greater is your incentive to look for substitues when the price of the item rises,and if the smaller the share of your budegt get an item accounts for ,the smaller is your incentive to find out substitues when the price of the item down .So a consumer’s price elasticity of demand for a good depend on the fraction of the consumer’s income spent on that good.2.Why does the price elasticity of demand for a good decline aswe move down along a straight-line demand curve ?As we move down along a straight-line demand curve ,the price is move down,then the quantity also move down with the price .According the formula ofpice elasticity of demand is (P/Q)×(1/Slope),the price elasticity of demand for a good decline as we move down along a straight-line demand curve.3.Under what conditions will an increase in the price of aproduct lead to a reduction in total spending for that product ? When the elastic﹥1,and the quantity of the demand go down,there are will an increase in the price of a product lead to a reduction in total spending for that product.4.Why do economists pay little attention to the algebraic signof the elasticity of demand for a good with respect to its own price ,yet pay careful attention to the algebraic sign of the elasticity of demand for a good with respect to another good’s price ?For own price of goods,because price changes are always in the opposite direction from changes in quantity demanded,so for convenience,the economists dorp the nagetive sign and speak of price elasticities in terms of absolute value.For another good’s price,when the cross-priceelasticity of demand for one good with respect to the price of another good is positive ,the two goods are substitutes;when the cross-price elasticity of demand is negative,the two goods are complements.So it is important to note their algebraic sign carefully.5.Why is supply elasticity higher in the long run than in theshort run ?Because it takes time for producters to switch from one activity to another,and because it takes time to build new machines and factories and train additional skilled workers,the price elasticity of supply will higher for most goods in the long run than in the short run.PROBLENMS1.Calculate the price elasticity of demand at points A,B,C,D,and E on the demand curve below.1/slope=100/100=1;Point A:ε=(P/Q)×(1/slope)=∞the quantity of demand infinitely close to zero,so A is perfectly elastic.Point B:ε= (P/Q)×(1/slope)= (75/25)×1=3;Point C:ε=(P/Q)×(1/slope)= (50/50)×1=1;Point D:ε=(P/Q)×(1/slope)= (25/75)×1=1/3;Point E:ε=(P/Q)×(1/slope)=(0/100)×1=0,so the point E is perferctly inelastic.2. The schedule below shows the number of packs of bagelsbought in Davis, California, each day at a variety of prices.ABCDE100 7550250 25 5075 100 PriceQuantitya.Graph the daily demand curve for packs of bagels inDavis.b. Calculate the price elasticity of demande at the point on the demand curve at which the price of bagels is $3 per pack.Slope=6/18000=1/3000ε= (P/Q)×(1/slope)= (3/9000)×3000=1so the price elasticity of demand is 1.c. If all bagel shops increase the price of bagels from $3 per pack to $4 per pack, what would happen to total revenus? The initial total revenue:TR 1=P*Q=3×9000=27000 After change total revenue:TR 2=P*Q=4×Price of bagels($/pack) 0 Number of packs purchased per day1234563000 6000 9000 12000 15000 180006000=24000TR2－TR1 =24000－27000=﹣3000So total revenus will decrease 3000$.d.Calculate the price elasticity of demande at the point onthe demand curve where the price of bagels is $2 per pack.Slope=6/18000=1/3000ε= (P/Q)×(1/slope)= (2/12000)×3000=1/2so the price elasticity of demand is 1/2.e.If bagel shops increase the price of bagels from $2 perpack to $3 per pack, what would happen to total revenus?The initial total revenue:TR1=P*Q=2×12000=24000After change total revenue:TR2=P*Q=3×9000=27000TR2－TR1=27000－24000=3000So total revenus will increase 3000$.3.Suppose,whlie rummaging through your uncle’s closet, you found the original painting of Dogs Playing Poker,a valuable piece of art.You decide to set up a display in your uncle’sgarage.The demand curve to see this valuable piece of art is as shown in the diagram. What price should you charge if your goal is to maximize your revenues from tickets sold? On a graph,show the inelastic and elastic regions of the demand curve.For a good whose demand curve is a straight line,total expenditure reaches a maximum at the price corresponding to the midpoint of the demand curve .So when the price is 6$,and the quantity is 3, the total revenues can reaches a maxmum.Slope=12/6=2ε= (P/Q)×(1/slope)= (6/3)×(1/2)=1 so to achieve total revenues maxmum we should make 126Price($/visit)Quantity(visitors/day)the price is 6$.And demand is elastic on the top half,unit elastic at the midpoint A,and inelastic on the bottom half of a straight-line demand curve.(As shown in graph)4.Is the demand for a particular brand of car, like a Chevrolet, likely to be more or less price-elastic then the demand for all cars? Explain.The larger the share of your budget an item accounts for,the greater is your incentive to look for substitutes when the price of the item rises.So the high price goods tend to have higher price elasticities of demand.(1).when the price of the particular brand car higer than other cars ,there are more price-elastic; 126Price($/visit) Quantity(visitors/day) 3(2) when the price of the particular brand car lower than other cars,there are less price-elastic;(3) when the price of the particular brand car is similar with other cars,there are same price-elastic.5.Among the following groups—senior executives, junior executives, and students—which is likely to have the most and which is likely to have the least price-elastic demand for membership in the Association of Business Professionals ? The different group express different education level,and with the increasing of level,the number of the people would decreasing,and the quantity of the substitute is less ,because the demand will tend to be less elastic if the substitute not easy be found, so the senior executives is likely to have the least price-elastic demand for membership in the Association of Business Professionals.6.A 2 percent increase in the price of milk causes a 4 percent reduction in the quantity demanded of chocolate syrup . What is the cross-price elasticiy of demand for chocolate syrup with respect of the price of milk? Are the two goods complementsor substitutes?ε=△Q%/△P%=-4%/2%= -2,For another good ’s price, when the cross-price elasticity of demand is negative,the two goods are complements.7.What are the respective price elasticities of supply at A and B on the supply curve shown in the accompanying figure?Slope=△P/△Q=(6-4)/(12-9)=2/3;Point A:ε= (P/Q)×(1/slope)= (4/9)×(3/2)= 2/3;Point B:ε= (P/Q)×(1/slope)= (6/12)×(3/2)=3/4;So the price elasticity of supply is 2/3 at point A, 6 4 9 12 ABSΔP△Q Price Quantityand the price elasticity of supply is 3/4 at point B.8.Suppose that the ingredients required to bring a slice of pizza to market and their respective costs are as listed in the table:If these proportions remain the same no matter how many slices are made, and the inputs can be purchased in any quantities at the stated prices, draw the supply curve of pizza slices and compute its price elasticity.Because these proportions remain the same no matter Quanttity 120 pricehow many slices are made, and the inputs can be purchased in any quantities at the stated prices,so the price of the producter sold the goods have no change,then it is perfectly elastic supply.9.At point A on the demand curve shown, by what percentage will a 1 percent increase in the price of the product affect total expenditure on the product?Slope=6/18=1/3,price elasticity of demand at point A:ε= (P/Q)×(1/slope)= (4/6)×3=2;ε=(△Q%/△P%)=2,ε=x/1%=2 , x=2%,64618A0 P($/unit) Q(units/week)TR=TE,after change:TR2=4×(1+1%)×[6×(1-2%)]=23.7552, before change: TR1 =4×6=24,TR2－TR1=24-23.7552=0.6448The changed percentage of TR=0.6448/24≈3%. when elastic﹥1,if the price increase 1%,the total revenue would decrease 3%,and the total expenditure would decrease 3%.10.Suppose that ,in an attempt to induce citizens to conserve energy, the government enacted regulations requiring that all air conditioners be more efficient in their use of electricity. After this regulation was implemented, government officials were then surprised to discover that people used even more electricity than before. Using the concept of price elasticity, explain how this increase might have occurred.After the government enacted regulations,the power efficiency will improve,then the cost of using electricity relatively go down than before.According price-elastic ,when the price go down,the quantity would increase.Because the quantity increase,it means the quantity of using electricity go up.Sopeople used even more electricity than before.。
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.。
微观经济学第四章 习题答案
第四章生产论1、下面(表4—1)就是一张一种可变生产要素得短期生产函数得产量表:可变要素得数量可变要素得总产量可变要素得平均产量可变要素得边际产量1 22 103 244 125 606 67 708 09 63(2)该生产函数就是否表现出边际报酬递减？如果就是,就是从第几单位得可变要素投入量开始得？解答:(1)利用短期生产得总产量(TP)、平均产量(AP)与边际产量(MP)之间得关系,可以完成对该表得填空,其结果如表4—2所示:可变要素得数量可变要素得总产量可变要素得平均产量可变要素得边际产量1 2 2 22 12 6 103 24 8 124 48 12 245 60 12 126 66 11 67 70 10 48 70 8\f(3 4) 09 63 7 －7后开始逐步下降得这样一种普遍得生产现象。
本题得生产函数表现出边际报酬递减得现象,具体地说,由表4—2可见,当可变要素得投入量从第4单位增加到第5单位时,该要素得边际产量由原来得24下降为12。
2、用图说明短期生产函数Q＝f(L, eq \o(K,\s\up6(－)))得TP L曲线、AP L曲线与MP L曲线得特征及其相互之间得关系。
解答:短期生产函数得TP L曲线、AP L曲线与MP L曲线得综合图如图4—1所示。
图4—1由图4—1可见,在短期生产得边际报酬递减规律得作用下,MP L曲线呈现出先上升达到最高点A以后又下降得趋势。
从边际报酬递减规律决定得MP L曲线出发,可以方便地推导出TP L曲线与AP L曲线,并掌握它们各自得特征及相互之间得关系。
关于TP L曲线。
由于MP L＝eq \f(d TP L,d L),所以,当MP L＞0时,TP L曲线就是上升得;当MP L＜0时,TP L曲线就是下降得;而当MP L＝0时,TP L曲线达最高点。
换言之,在L＝L3时,MP L曲线达到零值得B点与TP L曲线达到最大值得B′点就是相互对应得。
微观 曼昆经济学原理-课后答案
第一章经济学十大原理复习题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。
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。
外部性是一个人的行为对旁观者福利的影响。
当一个人不完全承担(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。
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，由此产生经济生活中价格总水平上升。
货币量增长引起了通货膨胀。
10．短期中通货膨胀与失业如何相关?答：短期中通货膨胀与失业之间存在着权衡取舍，这是由于某些价格调整缓慢造成的。
政府为了抑制通货膨胀会减少流通中的货币量，人们可用于支出的货币数量减少了，但是商品价格在短期内是粘性的，仍居高不下，于是社会消费的商品和劳务量减少，消费量减少又引起企业解雇工人。
在短期内，对通货膨胀的抑制增加了失业量。
问题与应用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。
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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。
8
．生产者技术的变动引起了沿着供给曲线的变动，还是供给曲线的移动？价格的变化引起了沿着供给曲线
17
5
．考虑DVD
、电视和电影院门票市场。
A
．对每一对物品，确定它们是互补品还是替代品
·DVD
和电视
·DVD
和电影票
·电视和电影票
答：DVD 和电视机是互补品，因为不可能在没有电视的情况下看DVD。DVD 和电影票是替代品，因为一
部电影即可以在电影院看，也可以在家看。电视和电影
的变动，还是供给曲线的移动?
答：生产者技术的变动引起了供给曲线的移动，价格变化引起了沿着供给曲线的变动。
9
．给市场均衡下定义，描述使市场向均衡变动的力量。
答：当供给与需求达到了平衡的状态，即需求曲线与供给曲线相交于一点时，这一点叫做市场的均衡。使市
场达到均衡的力量是价格。当价格低于均衡价格时，市场上求大于供，供给者发现提高价格也不会减少销售量，
20
图4—16 自由体操着装的规定对运动衫市场的影响
D
．发明了新织布机。
答：新织布机的发明使运动衫
生产的技术水平提高，使运动衫的供给曲线向右下方移动，运动衫的价格下降，
均衡数量增加。
图4—17 新织布机的发明对运动衫市场影响
8
．调查表明，年轻人吸食的毒品增加了。在随后的争论中，
C
．工程师开发出用于家用旅行车生产的新的自动化机器。
答：决定供给的技术因素受影响，生产技术提高，会使家用旅行车的供给增加。
图4-6 工程师发明自动化机器的影响
D
．运动型多功能车价格上升。
答：决定需求的相关物品价格因素受到影响，由于运动型多功能车是家用旅行车的替代品，所以家用旅行车
．考虑家用旅行车市场。根据下面所列的每一个事件，分别指出哪一种需求或供给的决定因素将受到影响。
同时还要指出，需求或供给是增加了，还是减少了。然后画图说明该事件对家用旅行车价格和数量的影响。
A
．人们决定多生孩子。
答：决定需求和供给的预期因素都受到影响。人们预期孩子多了，家庭开支会增大，家用旅行车的需求会减
·警力的削减增加了在大街上得到毒品的可能性。
·教育投入的削减降低了人们对吸毒危险性的认识。
A
．用供求图分别说明这两种假设会如何引起毒品消费量的增加。
答：警力的减少将导致毒品的供给增加。如图1 所示，这会导致毒品的均衡价格下跌，均衡数量上升。
另一方面，教育投入的削减将导致对毒品的需求上升。这将推动均衡价格和数量上升，如图2 所示。
曲线没有改变。于是，软件市场的均衡价格上升，均衡数量增加。
图4—12 电脑软件市场供求图
由于打字机也可以用来打字，它和电脑是替代品。电脑芯片成本降低使电脑价格降低，销售量上升，人们对
打字机的需求会下降。打字机的价格下降，销售量下降。
19
图4—13 打字机市场供求图
7
．运用供求图，说明下列事件对运动衫市场的影响。
的需求会增加。如图4-4 所示。
E
．股市崩溃减少了人们的财产。
答：股市崩溃减少了人们的财产，收入的减少会使得对家用旅行车的需求下降（家用旅行车是正常物品），
供给不受影响。如图4-7 所示，家用旅行车的价格和数量均下降。
图4-7 股市崩溃的影响
4
．找出以下分析的漏洞：“如果更多的美国人进行低糖饮食，对面包的需求将会下降。面包的需求下降将
视机的均衡价格下降，均衡数量上升，如图4—8 所示。
图4—8 电视机的均衡价格下降，均衡价格上升
C
．再画两个图说明电视机市场的变动如何影响DVD
市场和电影票市场。
答：由于电视机和DVD 是互补品，电视机价格的下降使DVD 的需求增加。需求增加引起DVD 均衡价格上
升，均衡数量增加，如图4—9 所示。
答：
15
图4—2 加勒比地区旅馆房间的供求图
C．“当中东爆发战争时，汽油价格上升，而二手凯迪拉克车的价格下降。”
答：
图4—3 中东战争对凯迪拉车二手车的影响
2
．“练习本需求增加提高了练习本的需求量，但没有增加练习本的供给量。”这句话对还是错？解释原因。
答：这句话错，应该是“练习本需求增加提高了练习本的需求量，但没有增加练习本的供给。”因为只是某
引起面包的价格下降。然而，价格下降又将使需求增加。最后，在新的均衡，美国人所消费的面包数量可能比
最初还多”
答：如果对面包的需求下降，面包的均衡价格确实会下降。而价格下降会导致面包的需求量上升，但低糖饮
食不影响供给，因此，需求曲线仅沿着供给曲线在A 点—B 点间移动，新的均衡量和均衡价格均难超初始值。
格既反映了一种物品的社会价格，也反映了生产该物品的社会成本，它指引着个别决策者在大多数情况下实现了
整个社会福利最大化的结果。
问题与应用
1
．用供求图分别解释以下表述：
A
．“当寒流袭击佛罗里达时，全国超市中橘子汁的价格上升。”
答：
图4—1 全国超市中橘子汁的供求图
B
．“当每年夏天新英格兰地区天气变暖时，加勒比地区旅馆房间的价格直线下跌。”
答：物品的价格、买者的收入水平、相关物品的价格、买者的偏好和对物品的价格预期。
3
．什么是需求表和需求曲线？它们之间是什么关系？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。
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
的菠菜需求
14
曲线会发生什么变化?
答：根据低档物品的定义，菠菜对Popeye 来说是低档物品。因为Popeye 的收入减少了，他对菠菜的需求量
反而增大了。
对于低档物品来说，需求曲线是向右下方倾斜的，收入增加会引起需求曲线向外移动。菠菜的价格没变，但
答：因为啤酒和比萨饼是互补品，所以当啤酒价格上升而其他条件不变时，啤酒的需求会下降，比萨饼的需
求也下降。而比萨饼的供给并没有什么原因使它变动，这样，比萨饼的需求曲线会向左移动，而供给曲线不变。
达到市场均衡时的供给量、需求量、均衡价格都会下降。
11
．描述市场经济中价格的作用。
答：市场经济中价格是推动物品与劳务的需求量与供给量达到均衡状态的力量，是指导资源配置的信号。价
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。
4
．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。
5
．Popeye
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？简单描述一种不是完全竞争的市场。
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
．什么因素决定买者对一种物品的需求量?
6
．过去20
年间，技术进步降低了电脑芯片的成本。你认为这会对电脑市场产生怎样的影响？对电脑软件
呢？对打字机呢?
答：技术突破降低芯片成本，使电脑投入价格降低，电脑供给曲线向右下方移动，电脑的需求曲线并未改变。
于是电脑市场的均衡价格下降，均衡数量增加。
图4—11 电脑市场供求图
电脑与电脑软件是互补品。电脑市场均衡数量上升，软件的需求也会上升，需求曲线向右上方移动，而供给
A
．南卡罗莱纳的飓风损害了棉花作物
答：南卡罗莱纳的飓风减少了棉花的产量，使运动衫的投入价格上升，运动衫的供给曲线向左上方移动，运
动衫的价格上升，均衡数量减少。
图4—14 飓风损害了棉花作物对运动衫市场的影响
B．皮夹克价格下降。
答：皮夹克价格下降导致更多的人买皮夹克，使运动衫需求减少，结果是运动衫的需求曲线向左下方移动，
种因素影响了练习本的需求，使需求曲线移动或均衡点沿着需求曲线变动。没有什么因素
改变练习本的供给，即
练习本的供给曲线不会发生移动。但是一般说来，在其他
因素不变时，需求量的增大会引起供给量的增大。
3
波匹对菠菜的需求量增大了，所以Popeye 对菠菜的需求曲线是向外移动了。
6
．什么因素决定了卖者对一种物品的供给量?
答：价格、投入价格、技术、预期决定了卖者对一种物品的供给量。
7
．什么是供给表和供给曲线，它们之间是什么关系？为什么供给曲线向右上方倾斜?
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