1. Evaluating Impacts of Market Intervention In this lecture, we analyze the welfare effects of government policies to “intervene” the competitive markets (disturbances from market equilibrium). The tools we have learned are now very useful. Welfare effects: measured by consumer surplus and producer surplus (you should be familiar with them now). Elasticity: Measuring response to price changes.

2. Welfare in Competitive Equilibrium Between 0 and Q 0 producers receive a net gain from selling each product-- producer surplus. Consumer Surplus Quantity Price S D Q0Q0 5 9 Between 0 and Q 0 consumers receive a net gain from buying the product-- consumer surplus Producer Surplus 3 QDQD QSQS

3. Welfare in Competitive Equilibrium Without intervention, at the competitive market equilibrium, the total welfare is given by CS+PS. Producers receive PQ but area below S curve represents the resource cost, not gain.

4. Government Intervention The government may disturb the market outcomes because: -For achieving some objectives, it has to impose taxes. -It may consider the market price not consistent with some social objectives (equity, distribution, please political parties) Whatever the goals, we need to know the welfare cost/loss of policies.

5. Welfare Effects of a Price Ceiling The loss to producers is the sum of rectangle A and triangle C. B A C Consumers that can buy the good gain A Quantity Price S D P0P0 Q0Q0 P max Q1Q1 Q2Q2 Consumers that cannot buy, lose B Triangles B and C are losses to society – dead weight loss

6. Welfare Effects of a Price Ceiling Price is regulated to be lower than equilibrium level. Someone gain: Consumers who can still purchase the goods. Someone lose: Consumers who can’t purchase the goods due to smaller supply. Producers have to sell at lower price. Some producers quit due to lower price (< their costs). On the whole, gain < loss → net loss.

7. Welfare Costs of Intervention Net loss = B + C = +ΔCS – ΔCS – ΔPS The welfare loss is called deadweight loss. This is an efficiency loss. The fundamental reason of the existence of this loss is: Competitive market is the most efficient state. Disturbance from it (due to intervention) can only reduce the welfare. Government wants to achieve some goals (political favouritism, equity, etc). The cost is efficiency loss.

8. Welfare Effects of Price Floor B A C Quantity Price S D P0P0 Q0Q0 P min Q1Q1 Q2Q2 When price is regulated to be no lower than P min, the deadweight loss given by triangles B and C results.

9. Minimum Wage B The deadweight loss is given by triangles B and C. C A L1L1 L2L2 Unemployment w min Firms are not allowed to pay less than w min. This results in unemployment. S D w0w0 L0L0 L w A is gain to workers who find jobs at higher wage

10. Tax on Goods $t per unit of quantity is imposed on a good (paid by consumers or producers). The tax generates a difference between the price paid by consumers and the price received by producers. Consumers are concerned only with the price inclusive of tax (price paid by consumers). Buyers’ price P b on the D curve Producers are concerned only with the price exclusive of tax (price received by sellers). Sellers’ price P s on S curve. Equilibrium conditions: P b -P s = t in addition to Q d = Q s.

11. Tax on Goods Suppose suppliers are required to pay t per unit of the good sold. Without tax, they require P1 to supply Q1. With tax, they require P2, because they receive, excluding tax, only P1. Quantity Price Q1Q1 P 1 P 2 S’ S t

12. Tax on Goods With tax, new supply is S’. Equilibrium price for consumer is Pb. Suppliers receive only Ps = Pb – t. Quantity decreases to Q1. D S Quantity Price P0P0 Q0Q0 Q1Q1 P S price producers get P b price buyers pay Tax = $1.00 Without tax, equilibrium price is P0, quantity is Q0. S’

13. Tax on Goods Suppose consumers are required to pay the tax. Each unit of the good bought, t is required. They need to pay the price to the suppliers. Separately, they need to send $tQ to the government. Quantity Price Q1Q1 P 1 P 2 D’ D Without tax, they are willing to pay P2 to the suppliers for Q1. With tax, they are willing to pay only P1 because they need to pay an additional t to the government. t

14. Tax on Goods With tax, buyers will pay a total Pb for Q1. D S Quantity Price P0P0 Q0Q0 Q1Q1 P S price producers get P b price buyers pay Tax = $1.00 t will be sent directly to the government. But only Ps will be paid to sellers. Tax on sellers generates the same result as tax on buyers. Without tax, equilibrium price is P0 and quantity is Q0. D’

15. Tax on Goods Buyers lose A + B D S B D A C Quantity Price P0P0 Q0Q0 Q1Q1 P S price producers get P b price buyers pay Tax = $1.00 Government gains A + D in tax revenue. Sellers lose D + C The deadweight loss is B + C. Buyers’ tax burden A Sellers’ tax burden B

16. Tax Burdens Quantity Price S D S D Q0Q0 P0P0 P0P0 Q0Q0 Q1Q1 PbPb PSPS t Q1Q1 PbPb PSPS t Burden on Buyer Burden on Seller

17. Tax Burdens Relative tax burdens of consumers and producers depend on the relative elasticity of D and S. The fraction of tax borne by buyers is given by the “pass-through” formula: Es/(Es-Ed). (What happen if Ed = 0 or Es = 0 and diagrams?) The fraction of tax borne by sellers is given by : -Ed/(Es-Ed).

18. Subsidy $s per unit of quantity is given to the consumers (or producers). Consumers are willing to pay $s more to the sellers than before due to subsidy for the same Q. (or producers are willing to receive $s less than before from the consumers to supply the same Q) The benefit goes mostly to consumers if Ed/Es is small. The benefit goes mostly to sellers if Ed/Es is large.

19. Subsidy D S Quantity Price P0P0 Q0Q0 Q1Q1 PSPS PbPb Like a tax, the benefit of a subsidy is split between buyers and sellers, depending upon the elasticities of supply and demand. Producer receive P s while consumers pay P b. In new equilibrium, we have P s -P b =s. Subsidy

20. Price Supports Instead of regulating the price level to an above-equilibrium level, government may achieve this target by purchasing the goods at the free market. E.g. agricultural products. It promotes production. (Greater q effect than price floor.)

21. Price Supports B D A To maintain a price P s the government buys quantity Q g. CS down by A+B PS up by A+B+D Cost to gov’t E D + Q g QgQg Quantity Price S D P0P0 Q0Q0 PsPs Q2Q2 Q1Q1 E Net Loss to society is E – D

22. Import Quotas vs Tariffs Lobbied by exporters, many government imposes trade restriction, limiting imported goods. Two methods to restrict imports: quotas (quantity restriction), tariff (tax on imported goods) Even though WTO (GAAT) don’t endorse quotas, bilateral agreements on quotas are implemented outside WTO.

23. Tariffs World price P w → Import = Q D -Q S. Tariff → Import price rises to P* → Import down to Q D ’-Q S ’. Gain in PS: A Loss in CS: A+B+D+C Tariff revenue to gov’t: D Net welfare loss: B+C D CB QSQS QDQD Q’ S Q’ D A P* PwPw Q P D S

24. Import Quotas Quota: Q D ’-Q S ’. Push import price to P* Loss in CS: A+B+D+C Gain in PS (for domestic producers): A D → foreign producers’ profit (due to higher price) Net loss to the domestic sector: B+C+D D CB QSQS QDQD Q’ S Q’ D A P* PwPw Q P D S