《西方经济学》课程习题解答（微观经济学）CHAPTER 1 PRELIMINARIES.doc_大学文库

CHAPTER 1 PRELIMINARIES 一、QUESTIONS FOR REVIEW 1.It is often said that a good theory is one that can be refuted by an empirical data-oriented study. Explain why a theory that cannot be evaluated empi is not a good theory. There are two steps to consider when evaluating a theory:first,you should examine the reasonability of the theory's assumptions second,you should test the theory's predictions by comparing them with facts.If a theory cannot be tested,it cannot be accepted or rejected Therefore,it contributes little to our understanding of reality. 2.Which of the following two atements involves positive onomic analysis and which normative?How do the two kinds ofanalysis differ? a.Gasoline rationing(allocating to each individual a maximum amount of gasoline that can be purchased each year)is a poor social policy because it interferes with the workings of the competitive market system. Positive econmic analysis describes what is.Normative conomic analysis describes what ought to be.Statement (a)merges both types of analysis.First,statement (a)makes a positive statement that gasoline rationing"interferes with the workings of the competitive market system."We knowfromm analysis that a constraint placed on supply wil change the market equilibrium.Second,statement(a)makes the normative statement (i.e.a value judgment)that gasoline rationing is a poor social policy."Thus,statement(a) makes a normative comment based on a conclusion derived from positive economic analysis of the policy. b.Gasoline rationing is a policy under which more people are made worse off than are made better off. Statement (b)is itive becaus it states what the effect of gasoline rationing is without makingavalue judgment about the desirability of the rationing poliey. 3.Suppose the price of unleaded regular octane gasoline were 20 cents per gallon higher in New Jersey than in Oklahoma.Do you think there would be an opportunity for arbitrage (ie.,that firms could buy gas in Oklahoma and then sell it at a profit in New Jersey)?Why or why not?

CHAPTER 1 PRELIMINARIES 一、QUESTIONS FOR REVIEW 1. It is often said that a good theory is one that can be refuted by an empirical, data-oriented study. Explain why a theory that cannot be evaluated empirically is not a good theory. There are two steps to consider when evaluating a theory: first, you should examine the reasonability of the theory’s assumptions; second, you should test the theory’s predictions by comparing them with facts. If a theory cannot be tested, it cannot be accepted or rejected. Therefore, it contributes little to our understanding of reality. 2. Which of the following two statements involves positive economic analysis and which normative? How do the two kinds of analysis differ? a. Gasoline rationing(allocating to each individual a maximum amount of gasoline that can be purchased each year) is a poor social policy because it interferes with the workings of the competitive market system. Positive economic analysis describes what is. Normative economic analysis describes what ought to be. Statement (a) merges both types of analysis. First, statement (a) makes a positive statement that gasoline rationing “interferes with the workings of the competitive market system.” We know from economic analysis that a constraint placed on supply will change the market equilibrium. Second, statement (a) makes the normative statement (i.e., a value judgment) that gasoline rationing is a “poor social policy.” Thus, statement (a) makes a normative comment based on a conclusion derived from positive economic analysis of the policy. b. Gasoline rationing is a policy under which more people are made worse off than are made better off. Statement (b) is positive because it states what the effect of gasoline rationing is without making a value judgment about the desirability of the rationing policy. 3. Suppose the price of unleaded regular octane gasoline were 20 cents per gallon higher in New Jersey than in Oklahoma. Do you think there would be an opportunity for arbitrage (i.e., that firms could buy gas in Oklahoma and then sell it at a profit in New Jersey)? Why or why not?

Oklahoma and New Jersey represent separate geographic marketsfor gasolinebecause of high transportation costs If transportation ere,aprice nrease in would prompt arbitrageurs to buy gasoline in Oklahoma and sell it in New Jersey.It i unlikely in this case that the 20 cents per gallon difference in costs would be high enough to create a profitable opportunity for arbitrage.given both transactions costs and transportation costs. 4.In Example 1.3,what economic forces explain why the real price of eggs has fallen while the real price of a college education has increased?How have thes changes affected consumer choices? The price and quantity of gods e.g.eggs)and services (e.g.a oollege education)are determined by the interaction of supply and demand.The real price of eggs fell from 1970 to 1985 because of either a reduction in demand (consumers switched to lower-cholesterol food),areductionin production costs (improvements inegg production technology)or both. toother foods dec ed.The real price ofa col education because of either an increase in demand (e.g more people recognized the value of an education),an increase in the cost ofeducation (e.g,increase in staff salaries),or both. 5.Suppose that the Japanese ven rises against the U.s.dollar-that is.it will take more dollars to buy any given amount of Japanese yen.Explain why this increase simultaneously increases the real price of Japanese cars for U.S. con sumers and lowers the real price of U.S.automobiles for Japanese consumers As the value of the yen grows relative to the dollar,more dollars exchange for fewer yen Assume that the costs of production for both Japanese and U.S.automobiles remain unchanged.Then using the new exchange rate,the purchase of a Japanese automobile priced in yen requires more dollars.Similarly,the purchase of a U.S.automobile priced in dollars requires fewer yen. 6.The price of long-distance telephone service fell from 40 cents per minute in Coasumer Price Index increased by 0-percent over this period.wh 5-percent (18 cents/ cents) ecrea happened to the real price oftelephone service? Let the CPI for 1996 equal 1 and the CPI for 1999 equal 1.1,which reflects a 10% increase in the overallprice level.To find the real price oftelephone service ineach period. divide the nominal price by the CPI for that year.For 1996,we have 40/1 or 40 cents,and for 1999.we have 22/1.1 or 20 cents.The real price therefore fell from 40 to 20 cents a 50% decline. 二、EXERCISES 1.Decide whether each of the following statements is true or false and explair why: a.Fast food chains like MeDonald's,Burger King,and Wendy's operate all over the United States.Therefore the market for fast food is a national market

Oklahoma and New Jersey represent separate geographic markets for gasoline because of high transportation costs. If transportation costs were zero, a price increase in New Jersey would prompt arbitrageurs to buy gasoline in Oklahoma and sell it in New Jersey. It is unlikely in this case that the 20 cents per gallon difference in costs would be high enough to create a profitable opportunity for arbitrage, given both transactions costs and transportation costs. 4. In Example 1.3, what economic forces explain why the real price of eggs has fallen while the real price of a college education has increased? How have these changes affected consumer choices? The price and quantity of goods (e.g., eggs) and services (e.g., a college education) are determined by the interaction of supply and demand. The real price of eggs fell from 1970 to 1985 because of either a reduction in demand (consumers switched to lower-cholesterol food), a reduction in production costs (improvements in egg production technology), or both. In response, the price of eggs relative to other foods decreased. The real price of a college education rose because of either an increase in demand (e.g., more people recognized the value of an education), an increase in the cost of education (e.g., increase in staff salaries), or both. 5. Suppose that the Japanese yen rises against the U.S. dollar- that is, it will take more dollars to buy any given amount of Japanese yen. Explain why this increase simultaneously increases the real price of Japanese cars for U.S. consumers and lowers the real price of U.S. automobiles for Japanese consumers. As the value of the yen grows relative to the dollar, more dollars exchange for fewer yen. Assume that the costs of production for both Japanese and U.S. automobiles remain unchanged. Then using the new exchange rate, the purchase of a Japanese automobile priced in yen requires more dollars. Similarly, the purchase of a U.S. automobile priced in dollars requires fewer yen. 6. The price of long-distance telephone service fell from 40 cents per minute in 1996 to 22 cents per minute in 1999, a 45-percent (18 cents/40 cents) decrease. The Consumer Price Index increased by 10-percent over this period. What happened to the real price of telephone service? Let the CPI for 1996 equal 1 and the CPI for 1999 equal 1.1, which reflects a 10% increase in the overall price level. To find the real price of telephone service in each period, divide the nominal price by the CPI for that year. For 1996, we have 40/1 or 40 cents, and for 1999, we have 22/1.1 or 20 cents. The real price therefore fell from 40 to 20 cents, a 50% decline. 二、EXERCISES 1. Decide whether each of the following statements is true or false and explain why: a. Fast food chains like McDonald’s, Burger King, and Wendy’s operate all over the United States. Therefore the market for fast food is a national market

This statement is false. People generally buy fast food within their current location and do not travel large distances across the United States just to buy a cheaper fast food meal. Given there is little potential for arbitrage between fast food restaurants that are located some distance from each other, there are likely to be multiple fast food markets across the country. b. People generally buy clothing in the city in which they live. Therefore there is a clothing market in, say, Atlanta that is distinct from the clothing market in Los Angeles. This statement is false. Although consumers are unlikely to travel across the country to buy clothing, suppliers can easily move clothing from one part of the country to another. Thus, if clothing is more expensive in Atlanta than Los Angeles, clothing companies could shift supplies to Atlanta, which would reduce the price in Atlanta. Occasionally, there may be a market for a specific clothing item in a faraway market that results in a great opportunity for arbitrage, such as the market for blue jeans in the old Soviet Union. c. Some consumers strongly prefer Pepsi and some strongly prefer Coke. Therefore there is no single market for colas. This statement is false. Although some people have strong preferences for a particular brand of cola, the different brands are similar enough that they constitute one market. There are consumers who do not have strong preferences for one type of cola, and there are consumers who may have a preference, but who will also be influenced by price. Given these possibilities, the price of cola drinks will not tend to differ by very much, particularly for Coke and Pepsi. 2. The following table shows the average retail price of butter and the Consumer Price Index from 1980 to 2001. ˇ 1980 1985 1990 1995 2000 2001 CPI 100 130.58 158.62 184.95 208.98 214.93 Retail Price of butter $1.88 $2.12 $1.99 $1.61 $2.52 $3.30 (salted, grade AA, per lb.) a. Calculate the real price of butter in 1980 dollars. Has the real price increased/decreased/stayed the same since 1980? Real price of butter in year X =  CPI1980 CPIyear X * nominal price in year X . 1980 1985 1990 1995 2000 2001 $1.88 $1.62 $1.25 $0.87 $1.21 $1.54 Since 1980 the real price of butter has decreased