If the marginal propensity to consume is 0.5, what is the value of the expenditure multiplier?

The reason that the production possibilities frontier is usually a bow-shaped curve instead of a straight line is that

a. it makes it easier to illustrate the concepts of scarcity and prices with a bow-shaped curve than it is with a straight line b. early economists began drawing them in this way and the convention has continued throughout the years c. output eventually reaches a maximum and then declines d. resources are not perfectly adaptable to the production of all goods e. the frontier will shift outward over time

The production possibilities curve shows different combinations of goods that:

a. can be consumed by households. b. can be consumed by firms. c. can be produced with the available technology. d. are produced and consumed by firms. e. are bought and sold in the market.