A firm estimates that when output is 10, its total costs are $900 . It also finds that when output is 11, its total costs are $920 . The marginal cost of the eleventh unit of output is:

If a goal of a nation's residents is to increase marginal productivity, they should increase

A) expenditures on education. B) the inheritance tax. C) exports. D) the marginal propensity to consume.

When economists make normative statements, they are

a. speaking as scientists. b. speaking as policy advisers. c. making claims about how the world is. d. revealing that they are very liberal in their views of how the world works.