Countries as well as families benefit from the ability to trade with one another. Trade allows countries to specialize in what they do best and to en… - Greg Mankiw

It is too early to say there is a consensus about how all these topics fit together. Yet one can say that the new classical challenge has been met: Keynesian economics has been reincarnated into a body with firm microeconomic muscle.

Microeconomics and macroeconomics are closely intertwined. Because changes in the overall economy arise from the decisions of millions of individuals, it is impossible to understand macroeconomic developments without considering the associated microeconomic decisions.

Economics is a young science, and there is still much to be learned. Economists sometimes disagree because they have different hunches about the validity of alternative theories or about the size of important parameters that measure how economic variables are related.