In the absence of trade barriers, patterns of trade are driven by comparative advantage.

According to your text, the economic way of thinking focuses on

A) actions, interactions, and consequences. B) intentions, motivations, and results. C) hypothesis generation, determination of control group, and testing of hypothesis. D) id, ego, and superego.

When external benefits are present,

A) competitive markets are efficient. B) competitive markets are inefficient. C) a tax is required to eliminate the inefficiency. D) property rights have already been established.