平狄克《微观经济学》(第七版)08.ppt

1、Fernando&Yvonn QuijanoPrepared by:ProfitMaximizationand CompetitiveSupply8C H A P T E RCopyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.Chapter 8:Profit Maximization and Competitive Supply2 of 36Copyright 2009 Pearson Education,Inc.Publishing as Pr

2、entice Hall Microeconomics Pindyck/Rubinfeld,7e.CHAPTER 8 OUTLINE8.1Perfectly Competitive Markets8.2Profit Maximization8.3Marginal Revenue,Marginal Cost,and Profit Maximization8.4Choosing Output in the Short Run8.5The Competitive Firms Short-Run Supply Curve8.6The Short-Run Market Supply Curve8.7Cho

3、osing Output in the Long Run8.8The Industrys Long-Run Supply CurveChapter 8:Profit Maximization and Competitive Supply3 of 36Copyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.PERFECTLY COMPETITIVE MARKETS8.1The model of perfect competition rests on

4、three basic assumptions:(1)price taking,(2)product homogeneity,and(3)free entry and exit.Price TakingBecause each individual firm sells a sufficiently small proportion of total market output,its decisions have no impact on market price.price taker Firm that has no influence over market price and thu

5、s takes the price as given.Product HomogeneityWhen the products of all of the firms in a market are perfectly substitutable with one anotherthat is,when they are homogeneousno firm can raise the price of its product above the price of other firms without losing most or all of its business.Chapter 8:

6、Profit Maximization and Competitive Supply4 of 36Copyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.PERFECTLY COMPETITIVE MARKETS8.1Free Entry and Exit free entry(or exit)Condition under which there are no special costs that make it difficult for a f

7、irm to enter(or exit)an industry.When Is a Market Highly Competitive?Because firms can implicitly or explicitly collude in setting prices,the presence of many firms is not sufficient for an industry to approximate perfect competition.Conversely,the presence of only a few firms in a market does not r

8、ule out competitive behavior.Chapter 8:Profit Maximization and Competitive Supply5 of 36Copyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.PROFIT MAXIMIZATION8.2Do Firms Maximize Profit?The assumption of profit maximization is frequently used in micr

9、oeconomics because it predicts business behavior reasonably accurately and avoids unnecessary analytical complications.For smaller firms managed by their owners,profit is likely to dominate almost all decisions.In larger firms,however,managers who make day-to-day decisions usually have little contac

10、t with the owners(i.e.the stockholders).In any case,firms that do not come close to maximizing profit are not likely to survive.Firms that do survive in competitive industries make long-run profit maximization one of their highest priorities.Alternative Forms of Organization cooperative Association

11、of businesses or people jointly owned and operated by members for mutual benefit.Chapter 8:Profit Maximization and Competitive Supply6 of 36Copyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.PROFIT MAXIMIZATION8.2Nationwide,condos are a far more comm

12、on than co-ops,outnumbering them by a factor of nearly 10 to 1.In this regard,New York City is very different from the rest of the nationco-ops are more popular,and outnumber condos by a factor of about 4 to 1.What accounts for the relative popularity of housing cooperatives in New York City?Part of

13、 the answer is historical.Housing cooperatives are a much older form of organization in the U.S.The building restrictions in New York have long disappeared,and yet the conversion of apartments from co-ops to condos has been relatively slow.The typical condominium apartment is worth about 15.5 percen

14、t more than a equivalent apartment held in the form of a co-op.It appears that in New York,many owners have been willing to forgo substantial amounts of money in order to achieve non-monetary benefits.Chapter 8:Profit Maximization and Competitive Supply7 of 36Copyright 2009 Pearson Education,Inc.Pub

15、lishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.MARGINAL REVENUE,MARGINAL COST,AND PROFIT MAXIMIZATION8.3 profit Difference between total revenue and total cost.(q)=R(q)C(q)marginal revenue Change in revenue resulting from a one-unit increase in output.Profit Maximization in the Short R

16、unFigure 8.1A firm chooses output q*,so that profit,the difference AB between revenue R and cost C,is maximized.At that output,marginal revenue(the slope of the revenue curve)is equal to marginal cost(the slope of the cost curve)./q=R/q C/q=0MR(q)=MC(q)Chapter 8:Profit Maximization and Competitive Supply8 of 36Copyright 2009 Pearson Education,Inc.Publishing as Prentice Hall Microeconomics Pindyck/Rubinfeld,7e.MARGINAL REVENUE,MARGINAL COST,AND PROFIT MAXIMIZATION8.3Demand and Marginal Revenue fo