单选题 At the equilibrium levels of output and price in a competitive industry without taxes: A. consumer surplus is maximized. B. producer surplus is maximized. C. the sum of producer and consumer surplus is maximized.

【正确答案】 C

【答案解析】At competitive equilibrium the sum of consumer and producer surplus is at its maximum level Neither consumer nor producer surplus is necessarily at a maximum at the equilibrium output and price. Which surplus is larger or smaller depends on the elasticity of supply and demand.