Psychologically, the pain of losing something is roughly twice as powerful as the pleasure of gaining the exact same thing. Giving up $100 hurts more than winning $100 feels good.

Humans are not purely self-interested; we care about fairness, equity, and reciprocity. This text investigates how social norms influence economic choices, from why we tip waiters we will never see again to why we punish freeloaders even at a cost to ourselves.

Why go through the effort of reading the PDF? Because behavioral economics is the most actionable branch of economics today. Here are three domains where Just’s principles are used right now.

If you are a psychology major who hates math, choose a pop-science book. If you are an economics, public policy, or marketing major who wants to run regressions and design experiments, David R. Just is your best choice.

Classical economics assumes humans discount the future at a constant, consistent rate (exponential discounting). Behavioral economics proves that human discounting is inconsistent, a phenomenon known as .