Any policy that seeks to influence the level of aggregate demand is called

If a firm in monopolistic competition is earning an economic profit,

A) it is in the long run. B) other firms can enter the market. C) it can do so because it is "monopolistic" and other firms will have a hard time competing with it. D) its average cost must exceed its marginal cost. E) The question errs because firms in monopolistic competition cannot earn an economic profit.

Cruise liners offer last minute deals because

a. The marginal cost is higher than the marginal revenue since fixed costs are sunk b. The marginal costs of an additional passenger are very low at that point and companies gain by lowering prices c. The average cost of an additional passenger is very low at that point and companies gain by lowering prices d. All of the above