Refer to the figure above. What is the producer surplus when Lithasia engages in trade and the government imposes a tariff of $1 on chairs?

Economists first began studying the relationship between changes in aggregate expenditures and changes in GDP

A) at the end of the Civil War. B) during the Great Depression. C) during the Industrial Revolution. D) in the 1950s.

Few firms in the United States are monopolies because

A) few firms experience economies of scale. B) monopolies are technically illegal in the United States. C) when a firm earns profits, other firms will enter its market. D) most firms produce products for which there are no close substitutes.