The page shows the central concepts with descriptions below.

The concepts are listed as follows: The Cost-Benefit Principle, The Opportunity Cost Principle, The Marginal Principle, and Interdependence Principle.

The text below reads, Apply the core principles, in this order. A flow chart below shows the same central concepts from left to right. The text below the marginal principle reads, Address marginal questions, instead of how many questions. The text below the cost-benefit principle reads, Assess the marginal costs and benefits. The text below the opportunity cost principle reads, Which costs? The opportunity costs. The text below the interdependence principle reads, Take account of broader effects of your decisions. The text below the flowchart reads, To forecast the decisions others make, put yourself in someone else’s shoes. If you had their objectives and constraints, what decision would you make?