It is profitable to hire units of labor as long as the value of marginal product:

Compared to corporations, businesses that are proprietorships

A) are far more numerous. B) account for a larger percentage of the economy's total revenue each year. C) can raise capital more cheaply. D) All of the above are correct answers.

Movements along the demand curve are called changes in

a. demand b. opportunity costs c. quantity demanded d. the substitution effect e. preferences