Efficiency and Exchange 1
Market Equilibrium and Efficiency n A market equilibrium is efficient… l …if price and quantity take any other than their equilibrium values, a transaction that will make at least some people better off without harming others can always be found. Slide 2
A Market in Which Price Is Below the Equilibrium Level S Price ($/gallon) 2. 50 2. 00 1. 50 1. 00. 50 D 1 2 3 4 5 Quantity (1, 000 s of gallons/day) Slide 3
How Excess Demand Creates an Opportunity for a Surplus-Enhancing Transaction S Price ($/gallon) 2. 50 • If P = $1 then QS = 2, 000 gallons/day • At 2, 000 gallons the consumer is willing to pay $2 and the MC = $1 • If the buyer pays $1. 25 for an extra gallon, producer is $. 25 better off, and the consumer is $. 75 better off, or economic surplus increases by $1. 00 • At $1, the market is not efficient 2. 00 1. 50 1. 25 1. 00. 50 D 1 2 3 4 5 Quantity (1, 000 s of gallons/day) Slide 4
How Excess Supply Creates an Opportunity for a Surplus-Enhancing Transaction S Price ($/gallon) 2. 50 • If P = $2 then QD = 2, 000 gallons/day • Additional output costs only $1 • This is $1 less than a buyer would pay • If the buyer pays the seller $1. 75, the buyer gains an economic surplus of $0. 25 then the seller gains an economic surplus of $0. 75 2. 00 1. 75 1. 50 1. 00. 50 D 1 2 3 4 5 Quantity (1, 000 s of gallons/day) Slide 5
Market Equilibrium and Efficiency n n n When price is above or below the equilibrium, the quantity exchanged will be below the equilibrium. The vertical value on the demand curve (marginal benefit) is greater than the vertical value on the supply curve (MC). Only the equilibrium will maximize economic surplus. Slide 6
Cash on the Table n n n When any “frictions” (typically government regulation) prevents the market price from reaching its equilibrium level, the total economic surplus (economic benefits less opportunity costs) available for buyers and sellers is diminished. Mutually beneficial exchanges are always possible when a market is out of equilibrium. When people have failed to take advantage of all mutually beneficial exchanges, there is "cash on the table. ” 7
Social optimality n n n The socially optimal quantity of any good is the quantity that maximizes the total economic surplus that results from producing and consuming the good. Cost-benefit principle l keep expanding production of the good as long as its marginal benefit is at least as great as its marginal cost. Socially optimal quantity is that level for which the marginal cost and marginal benefit of the good are the same. 8
The Cost of Preventing Price Adjustments n Price Ceilings: Do They Help the Poor? A Price Ceiling for Housing Space l Also known as rent control l Slide 9
Economic Surplus in an Unregulated Market for Housing Space 2. 00 Consumer surplus = $900/day 1. 80 S 1. 60 1. 40 Producer surplus = $900/day Price ($) 1. 20 1. 00 Without price controls: • Equilibrium Price = $1. 40 • Consumer surplus = (1/2)(3, 000)(. 60) = $900/day • Producer surplus = (1/2)(3, 000)(. 6) = 900/day • Economic surplus = $1, 800/day D . 80 1 2 3 4 5 8 Quantity of Housing /day Slide 10
The Waste Caused by Price Controls S 2. 00 Price Ceiling set at $1. 00 Consumer surplus = $900/day 1. 80 1. 60 Lost economic surplus = $800/day 1. 40 Price ($) 1. 20 1. 00 Producer surplus = $100/day D . 80 With price controls: • Producer surplus = (1/2)(1, 000)(. 20) = $100/day or a loss of $800/day • Economic surplus = $1, 000 or a loss of $800/day 1 2 3 4 5 8 Quantity of Housing /day Slide 11
The Cost of Preventing Price Adjustments n The reduction in economic surplus from a price ceiling will be underestimated when The consumers who receive the product are not the consumers who value it the most. l Consumers take costly actions to enhance their chances of being served. u. Non-price competition l Slide 12
Non-price Competition n If sub-lease is allowed, existing tenants may sub-lease part of their spaces to those tenants that are willing to pay more than the price ceiling. If sub-lease is not allowed, shortage and non-price competition will develop. Discrimination based on non-money considerations such as race, gender, marital status, pet ownership, and personalities l Dissipation of rent
Rent Control in the Long Run n If costs of maintaining and producing housing has increased, esp. during high inflation situation l Quality of housing deteriorates u. Reduce l excess demand or “shortage” Amount supplied would decrease in time as residential space (under rent control) will be converted to other uses, e. g. , office space u. E. g. Housing in New York City and Los Angeles
The Cost of Preventing Price Adjustments n Question l What program could be used to help the poor get housing spaces that would be more efficient than a price ceiling? Slide 15
When the Pie Is Larger, Everyone Can Have a Bigger Slice Surplus with price controls R Surplus with income transfers and no price controls R P P With price controls set at $1. 00 the economic surplus is $1, 000/day *R = economic surplus received by rich people *P = economic surplus received by poor people Without price controls & with income transfers economic surplus is $1, 800/day *R & P have the same share and a much larger economic surplus Slide 16
The Cost of Preventing Price Adjustments n Question l What would be a potential cost of income transfers? Slide 17
The Cost of Preventing Price Adjustments n Price Subsidies: Do They Help the Poor? By how much do subsidies reduce total economic surplus in the market for bread? l Assume a small nation imports all its bread at the world price of $2. 00 l Slide 18
Price of bread ($/loaf) Economic Surplus in a Bread Market Without Subsidy Economic surplus maximized where MC($2) = MB($2) at 4 million loaves 5. 00 4. 00 Consumer surplus = $4, 000/month 3. 00 S World price = $2. 00 1. 00 D 2 4 6 8 Quantity (millions of loaves/month) Slide 19
The Reduction in Economic Surplus from a Subsidy n Assume a $1/loaf subsidy Consumers buy 6 million loaves l Consumer surplus will increase to $9 million l Economic surplus will fall by $1 million l Slide 20
Price of bread ($/loaf) The Reduction in Economic Surplus from a Subsidy 5. 00 • The cost of the subsidy = $6 million/month • The benefit of the subsidy = $5 million/month • Loss of economic surplus = $1 million /month Consumer surplus = $4, 000/month Reduction in total economic surplus = $1, 000/month 4. 00 3. 00 S World price = $2. 00 Domestic price with subsidy 1. 00 D 2 4 6 8 Quantity (millions of loaves/month) Slide 21
The Cost of Preventing Price Adjustments n Price Subsidies l How could we provide assistance to low income consumers more efficiently? Slide 22
The Cost of Preventing Price Adjustments n Economic Naturalist l First-Come, First-Served Policies u Why does no one complain any longer about being bumped from an overbooked flight? Slide 23
Equilibrium in the Market for Seats on Oversold Flights Demand for remaining on the flight Supply of seats Price ($/seat) 60 24 33 37 Seats Slide 24
Equilibrium in the Market for Seats on Oversold Flights Price ($/seat) 60 First-come, First-served • Average reservation prices = (60+59+…+24)/37 = $42/passenger • 4 bumped @ $42 each or $168 loss in economic surplus Supply of seats 27 24 33 37 Seats Slide 25
Equilibrium in the Market for Seats on Oversold Flights Price ($/seat) 60 Compensation Policy • $27 = reservation price (compensation) to get 4 passengers to volunteer to stay • The cost of the compensation = 4 x $27 = $108 minus the economic surplus to the passengers of $6 = $102 Supply of seats 27 24 33 37 Seats Slide 26
The Cost of Preventing Price Adjustments n Example l How should a tennis pro handle an overbooking problem? Slide 27
The Cost of Preventing Price Adjustments Player Arrival time Reservation price Ann 9: 50 A. M. $4 Bill 9: 52 A. M. 3 Carrie 9: 55 A. M. 6 Dana 9: 56 A. M. 10 Earl 9: 59 A. M. 2 • 5 bookings for 3 slots • All 5 show up for the lesson • How can the tennis pro minimize the cost of rescheduling two students? • HINT: First-come, First-served or compensation Slide 28
The Cost of Preventing Price Adjustments n What do you think? l Why offer compensation when the cost of first-come, first-served to the seller is zero? Slide 29
The Marginal Cost Pricing of Public Services n Example l How much should a city charge for water, electricity, or some other service? Slide 30
The Marginal Cost Curve for Water Ocean Cost (cents/gallon) 4. 0 Three sources of water • Spring: 1 million gallons/day @ 0. 2 cents/gallon • Lake: 2 million gallons/day @ 0. 8 cents/gallon • Ocean: 4 cents/gallon Lake Spring 0. 8 0. 2 1 3 Water supplied (millions of gallons/day) Slide 31
The Marginal Cost Curve for Water n Example l How much should a city charge for water? Slide 32
The Marginal Cost Curve for Water Ocean Cost (cents/gallon) 4. 0 Assume • If P = 4 cents/gallon, Q = 4 million gallons Lake Spring Question • Why should all residents pay 4 cents per gallon 0. 8 0. 2 1 3 Water supplied (millions of gallons/day) Slide 33
Taxes and Subsidies n Effect of a sales tax on price and quantity l n Imposition of a sales tax on goods lower their sales but increase their prices (in most cases). Does it matter whether the tax is imposed on consumer or producers? l Economic incidence of a tax is independent of its legal incidence
Taxes and Subsidies n Who bears the burden of the tax? Consumers or producers l n Effect of Subsidies (negative taxes) l n Depends on the relative elasticity of demand supply Opposite effect to sales tax Taxes and Efficiency
The Effect of a Tax on the Equilibrium Quantity and Price of Avocados Without a tax P = $3/lb and Q = 3 million lbs/month S + tax S 6 Price ($/pound) 5 With a tax of $1/lb • MC increases by $1/lb • Supply shifts up by $1 • P = $3. 50; Q = 2. 5 million • Consumers and producers share the burden of the tax equally • Producers receive $2. 50/lb • Consumers pay $3. 50/lb 4 3. 50 3 2. 50 2 1 D 1 2 3 4 5 2. 5 Quantity (millions of pounds/month) Slide 36
Government levies taxes on consumers: upward slopping supply $t / unit P 1 – Net Price received by seller P P 2 – Gross Price received by the buyers (P 0 +a) t=a+b P 2 P 0 P 1 S a – borne by consumer a b – borne by producer b t D D’ Q 1 Q 0 Q
Government levies taxes on sellers: upward slopping supply $t / unit P 2 – Gross price received by seller P P 1 – Net price received by the seller S’ P 2 P 0 P 1 S a – borne by consumer a b – borne by producer b D Q 1 Q 0 Q
Government levies taxes on sellers: vertical supply $t / unit P 0 – Price before/after the new tax P S P 1 – Net price received by the seller after the new tax P 0 Consumers bear no burden t P 1 Producers bear full burden D Q 0 Q
Government levies taxes on consumers: vertical supply $t / unit P 0 – Price received by the seller prior to the new tax P S P 1 – Price received by the seller after the new tax P 0 -P 1 = t P 0 Consumers bear no burden t P 1 D t Producers bear full burden D’ Q 0 Q
The Effect of a Tax on Sellers of a Good with Infinite Price Elasticity of Supply Price ($/car) Assume a tax levy of $100 tax/car $20, 100 S + $100 $20, 000 S • Supply shifts to $20, 100 • The burden of the tax falls entirely on the consumer D 1. 9 2. 0 Quantity (millions of cars/month) Slide 41
Taxes and Efficiency n Who Pays a Tax? l When supply is perfectly elastic, the tax burden will fall entirely on the consumer. Slide 42
In a Nutshell n Economic incidence of a tax is independent of its legal incidence l It does not matter whether the government imposes the tax on the sellers or the buyers, the ultimate burden of the tax depends on the relative elasticity of demand supply. l In the case of an infinite inelastic supply curve (e. g. , lands and human capital) , sellers bear the full burden of the tax, while consumers bear none. In contrast, consumers bear the full burden of the tax if the demand curve is perfectly inelastic.
Sales Tax on Food n If Hong Kong government proposes to levy a sale tax on rice? Who bears most of the tax burden? l Demand for food (relatively inelastic) and supply for food (relatively elastic). why?
Sales Tax on Food n The Japanese government protects her local farmers and imposes import restrictions on many agricultural produces, e. g. , apple. If a sale tax on apple is imposed in Japan, who bears most of the tax burden? Why?
Mandatory Provident Fund (MPF) n n n Currently, employers contribute a half of the MPF (5%) and employees contribute another half of it (5%). Who bears the burden of the MPF? Employers or employees? If government shifts the MPF share from 50 -50 sharing to 80 -20 sharing (with employers contribute 80% of the MPF), does employees benefit from this new law?
Taxes and Quality of Goods n n If government levies a tax (flat rate) by the bottle of wine, what is its effect on the sales of high-quality to low-quality wine? Suppose Hong Kong government passes a law and subsidizes college students to buy computers. Each student gets $200 cash when the buy a computer, what is this law on the sales of high-end to low-end computers?
Taxes and Efficiency n Question l How will a tax on cars affect their prices in the long run? Slide 48
Taxes and Efficiency n Deadweight Loss l The reduction in total economic surplus that results from the adoption of a policy Slide 49
The Deadweight Loss Caused by a Tax S + tax S 6 Price ($/pound) 5 4 Deadweight loss caused by tax 3. 50 3 2. 50 2 1 D 1 2 3 4 5 2. 5 Quantity (millions of pounds/month) Slide 50
Taxes and Efficiency n Question l How would you determine the economic feasibility of a tax? Slide 51
Elasticity of Demand the Deadweight Loss from a Tax Deadweight loss 2. 40 2. 00 S+T 2. 60 S 1. 40 D 1 Price ($/unit) S+T S 2. 00 1. 60 D 2 19 24 Quantity (units/day) 21 24 Quantity (units/day) The greater the elasticity of demand, the greater the deadweight loss from a tax Slide 52
Elasticity of Supply and the Deadweight Loss from a Tax Deadweight Loss S 2 + T Deadweight Loss S 1 + T S 2 S 1 2. 00 1. 65 D 57 72 Quantity (units/day) Price ($/unit) 2. 65 2. 35 2. 00 1. 35 D 63 72 Quantity (units/day) The greater the elasticity of supply, the greater the deadweight loss from a tax Slide 53
Taxes and Efficiency n What do you think? Why would a tax on land be efficient? l Would a tax on pollution increase economic surplus? l Slide 54
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