曼昆-经济学原理-复习资料整理

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Q4Why should policy makers think about incentives?

Policymakers need to think about incentives so they can understand how people will respond to the policies they put in place. The text's example of seat belts shows that policy actions can have quite unintended consequences. If incentives matter a lot, they may lead to a very different type of policy; for example, some economists have suggested putting knives in steering columns so that people will drive much more carefully! While this suggestion is silly, it highlights the importance of incentives.

Q6what does the invisible hand of the marketplace do?

The "invisible hand" of the marketplace represents the idea that even though individuals and firms are all acting in their own self-interest, prices and the marketplace guide them to do what is good for society as a whole.

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Q1How is economics like a science?

Economics is like a science because economists use the scientific method. They devise theories, collect data, and then analyze these data in an attempt to verify or refute their theories about how the world works. Economists use theory and observation like other scientists, but they are limited in their ability to run controlled experiments. Instead, they must rely on natural experiments.

Q5 Use a production possibilities frontier to describe the idea of “efficiency”?

The idea of efficiency is that an outcome is efficient if the economy is getting all it can from the scarce resources it has available. In terms of the production possibilities frontier, an efficient point is a point on the frontier, such as point A in Figure 4. A point inside the frontier, such as point B, is inefficient since more of one good could be produced without reducing the production of another good.

Q7What is the difference between a positive and a normative statement? Give an example of that.

Positive statements are descriptive and make a claim about how the world is, while normative statements are prescriptive and make a claim about how the world ought to be. Here is an example. Positive: A rapid growth rate of money is the cause of inflation. Normative: The government should keep the growth rate of money low.

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Q1 Explain how absolute advantage and comparative advantage differ.

Absolute advantage reflects a comparison of the productivity of one person, firm, or nation to that of another, while comparative advantage is based on the relative opportunity costs of the persons, firms, or nations. While a person, firm, or nation may have an absolute advantage in producing every good, they can't have a comparative advantage in every good.

Q4Will a nation tend to export or import goods to Question2.

A nation will export goods for which it has a comparative advantage because it has a smaller opportunity cost of producing those goods. As a result, citizens of all nations are able to consume quantities of goods that are outside their production possibilities frontiers.

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Q5Propeye’s income declines, and as a result, he buys more spinach. Is spinach an inferior or a normal goods? What happens to Popeye’s demand curve for spinach?

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.

Q8 Dose a change in producers’ technology lead to a movement along the supply curve? Does a change in price lead to a movement along the supply curve or a shift in the supply curve?

A change in producers' technology leads to a shift in the supply curve. A change in price leads to a movement along the supply curve.

Q9 Define the equilibrium of a market. Describe the forces that move a market towards its equilibrium.

The equilibrium of a market is the point at which the quantity demanded is equal to quantity supplied. 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