Social Cost Supply PRICE Demand Q. Q Q. Q QUANTITY Refer to Figure 10-2. This market is characterized by government intervention. O a positive externality. a negative externality. a price control. Refer to Figure 10-2. Without government intervention, the equilibrium quantity would be Q1 Q2. Q3 Refer to Figure 10-2. The socially optimal quantity would be O Q1 Q3. Q4. Refer to Figure 10-2. This market has no need for government intervention. would be more efficient with a tax on the product. would be more efficient with a subsidy for the product. O would maximize total well-being at Q3.