Consider the market for electric cars. Suppose that a electric car manufacturing facility dump sibuge externality for those living downstream from the facility. Producing additional electric cars imposes a constant per-unit external cost of $420. The following graph shows the demand (private value) curve and the supply (private cost) curve for electric cars. Use the purple points (diamond symbol) to plot the social cost curve when the external cost is $420 per unit. 1400 PRICE (Dollars per unit of electric cars) 1250 1120 960 840 700 140 420 140 0 0 0 D 1 QUANTITY (Units of electric cars) Supply (Private Cost) O Demand (Private Value) Social Cost units of electric cars, but the socially optimal quantity of electric car production is units The market equilibrium quantity is To create an incentive for the firm to produce the socially optimal quantity of electric cars, the government could impose a of 5

Consider two firms with the following marginal abatement costs (MAC) as a function of emissions (E): MAC_1 = 11 - 2E_1 MAC_2 = 8.5 - E_2, and assume marginal external damages (MED) from the aggregate emissions of both firms (E_Agg = E_1 + E_2) is: MED = .5E_Agg. To achieve the socially efficient level of aggregate emissions (E*_Agg), the government institutes a per unit subsidy to abatement equal to $____. Answer:

Consider two firms with the following marginal abatement costs (MAC) as a function of emissions (E): MAC_1 = 24 - 2E_1 MAC_2 = 20 - E_2, and assume marginal external damages (MED) from the aggregate emissions of both firms (E_Agg = E_1 + E_2) is: MED = 2E_Agg. To achieve the socially efficient level of aggregate emissions (E*_Agg), the government institutes a cap and trade policy and sets the cap equal to the socially efficient level of emissions (E*_Agg). If firm 2 is initially grandfathered 5 permits, it will buy more permits. (Note: your answer can be positive or negative; if it is positive, the firm is buying additional permits; if it is negative, the firm sells permits. So, for example, an answer of -10 implies that the firm sells 10 permits)

3. The effect of negative externalities on the optimal quantity of consumption Consider the market for electric cars. Suppose that a electric car manufacturing facility dumps sludge into a nearby river, creating a negative externality for those living downstream from the facility. Producing additional electric cars imposes a constant per-unit external cost of $600. The following graph shows the demand (private value) curve and the supply (private cost) curve for electric cars. Use the purple points (diamond symbol) to plot the social cost curve when the external cost is $600 per unit. PRICE (Dollars per unit of electric cars) 2000 1800 1600 1400 1200 1000 800 600 400 200 0 0 + 1 O □ ☐ O 2 3 4 5 QUANTITY (Units of electric cars) The market equilibrium quantity is ☐ Supply (Private Cost) 6 Demand (Private Value) 7 Social Cost (?) units of electric cars, but the socially optimal quantity of electric car production is To create an incentive for the firm to produce the socially optimal…