What feature did World War I, World War II, and the Cold War have in common? A. Communism and democracy were in opposition.
B. The United States at first tried to remain neutral.
C. Europe was divided into two competing alliances.
D. German aggression was a leading cause of conflict.

Mankiw attributes – chapter 1 and his 10 principles – differences in living standards within a countryover time and across countries at a moment in time to: a. the presence or absence of inflation and unemployment.b. the allocation of resources between private markets and the public sector.c. those that have dealt successfully with the efficiency v. equality tradeoff and those that haven’t.d. differences in productivity.e. ones that think at the margin and respond to incentives and those that don’t.