Concept · Cognitive Bias: Economic and consumer biases
House money effect
Origin: Thaler & Johnson, 1990
Biological Parallel
Birds with full caches engage in riskier foraging—approaching human feeders, exploring novel foods, entering exposed areas. Surplus changes the risk calculation: potential losses don't threaten survival, so exploration becomes affordable. This windfall courage appears across species: well-fed predators experiment with new prey; satiated animals explore. The house money effect reflects this adaptive shift: unexpected gains don't feel integrated into baseline resources, so losing them doesn't trigger survival-level loss aversion.