PART 1 : 『Principles of Economics 5th edition』 Gregory N. Mankiw

　1. The fundamental lessons about indivisual decisionmaking are that people face tradeoffs among alternative goals, that the cost of any action is measured in terms of forgone opportunities, that rational people make decisions by comparing marginal costs and benefits, and that people change their behaviors in responce to the incentives they face.

2. The fundamental lessons about interactions among people are that trade can be mutually beneficial , that markets are usually a good way of coordinating trade among people , and that the government can potentially improve market outcomes if there is some market failure or if the market outcome is inequitable.

3. The fundamental lessons about the economy as a whole are that productivity is the ultimate source of living standards, that money growth is the ultimate source of inflation, and the society faces a short-run tradeoff between inflation and unemployment.