中级微观经济学——理论与应用（第10版）（经济学经典教材·双语教学用书） 教学课件 ppt 作者 尼克尔森等 著 0324319681_67673

1、Chapter 11, 2006 Thomson Learning/South-Western,Applying the Competitive Model,2,Consumer Surplus,In Figure 11-1, the equilibrium price and quantity are P* and Q*. The demand curve, D, shows what people are willing to pay for the good. The total value of the good to buyers is given by the area below the demand curve from Q = 0 to Q = Q* (AEQ*0).,3,Price,P*,S,D,E,A,B,Quantity per period,Q*,0,FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus,4,Consumer Surplus,Consumers expenditur

2、es for Q* are given by the area P*EQ*0. Consumers receive a “surplus” (total value less what they pay) equal to the area AEP*, which is shaded gray in Figure 11-1.,5,Price,P*,S,D,E,A,B,Quantity per period,Q*,0,FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus,6,Producer Surplus,At the equilibrium shown in Figure 11-1, producers receive total revenue equal to the area P*EQ*0. If producers sold one unit at a time at the lowest possible price, producers would have been willing to p

3、roduce Q* for the payment of BEQ*0. Thus, producer surplus the the area P*EB shaded in green in Figure 11-1.,7,Price,P*,S,D,E,A,B,Quantity per period,Q*,0,FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus,8,Short-Run Producer Surplus,The positive slope of the short-run supply curve, S, in Figure 11-1 results from the diminishing returns to variable inputs that are encountered as output is increased. For production up to Q*, price exceeds marginal cost, so total short-run profits

4、 equal the area P*EB less fixed costs,9,Short-Run Producer Surplus,Producer surplus, the area P*EB, reflects the sum of total short-run profits and short-run fixed costs. Short-run producer surplus is the part of total profits that is in excess of the profits firms would have if they chose to produce nothing at all. As such, it is similar to consumer surplus.,10,Long-Run Producer Surplus,Consider the area P*EB in Figure 11-1 as long-run producer surplus. It measures all of the increased payments

5、 relative to the situation in which the industry produces no output. The inputs would have received lower prices if this industry had not produced output.,11,Ricardian Rent,The market equilibrium price and quantity, P*, Q*, are shown in Figure 11-2 (d). Low-cost farms, Figure 11-2 (a) and medium-cost farms, Figure 11-2 (b), earn long-run economic profits. Marginal farms, Figure 11-2 (c) earn zero economic profits,12,FIGURE 11-2 (d): The Market,Price,P*,B,E,S,D,Q per,period,Q*,13,FIGURE 11-2 (a):

6、 Low-Cost Farm,Price,P*,MC,AC,q per period,q*,14,FIGURE 11-2 (b): Medium-Cost Farm,Price,P*,MC,AC,q per period,q*,15,FIGURE 11-2 (c): Marginal Farm,q per period,Price,P*,q*,MC,AC,16,Price,P*,MC,AC,q per,period,q*,(a) Low-Cost Farm,Price,P*,MC,AC,q per,period,q*,(b) Medium-Cost Farm,Price,P*,MC,AC,q per,period,q*,(c) Marginal Farm,Price,P*,B,E,S,D,Q per,period,Q*,(d) The Market,FIGURE 11-2: Ricardian Rent,17,Ricardian Rent,Profits earned by the intramarginal farms can persist in the long run beca

7、use they reflect the returns to a scarce resource, low-cost land. Entry can not erode these profits because of the scarcity of the low-cost land. The sum of these long run profits (P*EB) is the producer surplus ( Ricardian rent).,18,Economic Efficiency,The competitive equilibrium is efficient in that it produces the largest surplus equal to the sum of producer and consumer surplus. In Figure 11-1, an output level of Q1 results in a loss of surplus equal to the area FEG. Consumers would be willin

8、g to pay P1 for a good that producers are willing to produce for P2, so mutually beneficial transactions exit.,19,Price,P2,P*,S,D,E,F,G,P1,A,B,Quantity per period,Q*,Q1,0,FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus,20,A Numerical Example,The market equilibrium is P* = $6 and Q* = 4. The equilibrium is shown as point E in Figure 11-3. At point E consumers are spending $24 ($64).,21,A Numerical Example,At point E in Figure 11-3, consumer surplus is $8 (= $44). Producers also

9、 gain a producer surplus of $8 at point E. Total consumer and producer surplus is $16. If price stays at $6 but output falls to 3, total surplus falls to $15.,22,Price,S,D,E,6,10,2,Tapes,per period,4,3,5,1,2,FIGURE 11-3: Efficiency in CD Sales,23,Price Controls and Shortages,In Figure 11-4 the market initially is in equilibrium at P1, Q1 (point E). Then demand increases from D to D. This would cause price to rise to P2 encouraging entry in the short-run. Eventually entry would bring the price down to P3 and the market would be in long-run equilibrium.,24,Price,P,1,P,3,SS,E,E,LS,P,2,Quantity,per period,Q,1,Q,3,D,D,Q,2,FIGURE 11-4: Price Controls and Shortages,25,Price Controls and Shortages,Suppose the government imposed a price control at the below equilibrium price of P1 when demand increased. Firms would only supply Q1 and no entry would take place. Since custom

《中级微观经济学——理论与应用（第10版）（经济学经典教材·双语教学用书） 教学课件 ppt 作者 尼克尔森等 著 0324319681_67673》由会员E****分享，可在线阅读，更多相关《中级微观经济学——理论与应用（第10版）（经济学经典教材·双语教学用书） 教学课件 ppt 作者 尼克尔森等 著 0324319681_67673》请在金锄头文库上搜索。