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）尼克尔森等著0324319681_67673上课用课件.ppt

Chapter 11 Applying the Competitive Model 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). FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus Consumer Surplus Consumers expenditures 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. FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus 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 produce Q* for the payment of BEQ*0. Thus, producer surplus the the area P*EB shaded in green in Figure 11-1. FIGURE 11-1: Competitive Equilibrium and Consumer/Producer Surplus 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 equal the area P*EB less fixed costs 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. 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 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. Ricardian Rent The market equili