In a world of scarcity, there has to be some way to ration the available resources. According to economists, the most efficient use of available resources occurs when rationing occurs via

Most tariffs have

A) only revenue effects. B) only protective effects. C) both protective and revenue effects. D) neither protective nor revenue effects.

Which of the following sayings best represents the concept of opportunity costs?

a. "A glass can be half empty or half full." b. "When in Rome, do as the Romans do." c. "There is no such thing as a free lunch." d. "No taxation without representation." e. "What's up?"