How are individual makes choices?

Fundamental principles behind the individual choices are as follows:

1. Resources are scarce.

2. The real cost of anything is what you should give up to get this

Opportunity cost

This is all about what you have to forgo to acquire your choice.

3. "How much", this is a decision at the margin.

Trade-offs

Marginal decisions and marginal analysis

4. People generally take advantage of opportunities to make them better off.

Incentives