Behavioral Economics: How Cognitive Biases Affect Financial Decisions and How to Correct Them
Behavioral economics applies psychology research methods to economics, studying how people actually decide rather than how they theoretically “should.” Daniel Kahneman (2002 Nobel Prize in Economics, author of *Thinking, Fast and Slow*) and the late Amos Tversky are the field’s most important founders, demonstrating systematic cognitive biases through large-scale reproducible experiments.
Major Cognitive Biases and Their Financial Implications
Loss Aversion: psychological research shows the pain of loss is approximately twice the pleasure of an equivalent gain. In investing: prematurely selling winning stocks (locking in gains) while holding losing stocks too long (waiting to break even) — the opposite of tax-optimal strategy (quickly realizing losses for tax deductions).
Anchoring Bias: over-relying on the first number encountered in decision-making. Stock investors often anchor on their purchase price, treating any price below it as a “real loss” — but the purchase price has no bearing on future stock performance.
Confirmation Bias: tendency to seek and weight information supporting existing views while ignoring contradictory evidence. Investors researching a stock more easily remember positive information while ignoring risk warnings, leading to overconfidence.
Overconfidence: research shows most people believe their investment ability exceeds average. Frequent retail traders systematically achieve lower long-term returns than infrequent investors (Barber & Odean, 2000) — partly due to overconfidence-driven excessive trading and market-timing attempts.
