Research suggests that fairness plays
a. no role because consumers do not tip at restaurants they'll never visit again.
b. a role because it generates network externalities.
c. a role only when it is required.
d. a role because consumers donate money to charity.
e. a role only when it provides a financial benefit.

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.