The U.S. Postal Service is an example of a(n):

The earnings gap between better- and lesser- educated workers has held steady

Indicate whether the statement is true or false

If the price of orange juice rises, the demand for grapefruit juice will

a. increase because the two goods are substitutes b. increase because it is a complement c. decrease because the two goods are substitutes d. decrease because the two goods are complements e. not change unless the price of grapefruit juice also changes