The conventions of national income accounting imply that saving and investment are equal for the economy as a whole and for individual households and firms

The figure above shows the marginal social cost curve of generating electricity and the marginal private cost curve. The marginal external cost when 100 billion kilowatt hours are produced is

A) 0¢ per kilowatt. B) 5¢ per kilowatt. C) 10¢ per kilowatt. D) 15¢ per kilowatt. E) 20¢ per kilowatt.

Which of the following statements about a firm's demand curve for labor is true?

a. It shows the relationship between the price of output and the quantity of output demanded. b. It usually has a negative slope. c. It is perfectly inelastic. d. It is derived from the labor supply curve. e. It is parallel to the demand curve for the firm's product.