One reason why household incomes differ is that the number of household members who are working differs. For example, among households in the bottom 20 percent based on income, only about one household in seven has a full-time, year-round worker. The median income for households with two earners is 91 percent higher than for households with only one earner

When a firm's long-run average total cost falls as its output increases, the firm is experiencing

A) economies of scale. B) diseconomies of scale. C) constant returns to scale. D) decreasing marginal returns. E) decreasing cost of marginal returns.

Which of the following resources is not essential in the production of a typical cheese pizza?

A) Dough B) Sauce C) Heat D) Fodder for cows E) Trick question: all of the above are essential.