In the inverted-U theory of R&D, which of the following industry concentration ratios would be most conducive to R&D (as a percentage of firm sales)?

The deadweight loss from a rent ceiling below the equilibrium rent is smallest when the supply of housing is

A) perfectly elastic. B) elastic but not perfectly elastic. C) unit elastic. D) inelastic but not perfectly inelastic. E) perfectly inelastic.

When should a firm increase its production?

a. When it is earning a positive profit. b. When its revenues are too low to cover the firm's fixed costs. c. When there is a fall in the price of its product. d. When its marginal revenue exceeds its marginal cost.