College graduation rates and college attendance rates are equally strongly correlated with family income

If a country's currency appreciates, which of the following will most likely happen?

a. Net exports will fall and aggregate demand will increase. b. Net exports will rise and aggregate demand will increase. c. Net exports will fall and aggregate demand will decrease. d. Net exports will rise and aggregate demand will decrease.

Economics is an empirical science, which means that economists

A) must use laboratory experiments to test their theories. B) evaluate a model or theory by whether its assumptions are consistent with the real world. C) try to prove their models are true by referring to logic. D) look for evidence to determine whether the model is useful or not.