Suppose we are modeling a "closed" economy. The only way its government can obtain more goods and services than it can claim with net tax revenues is for

Along with changes in the level of economic activity, measured by GDP, what other economic variable tends to rise and fall as a consequence?

a. precipitation b. regulation c. circulation d. unemployment

When the social costs exceed the private costs, economists state that there is

A) a positive externality. B) an underproduction of output. C) a negative externality. D) a waste of resources in production.