Ultimatum Game

The Ultimatum Game is a two-player economic decision-making task that reveals preferences for fairness and social norms. One player (proposer) receives money and offers a portion to a second player (responder). The responder accepts or rejects the offer; if accepted, both receive their share; if rejected, both receive nothing. Economic theory predicts responders should accept any positive offer (better than zero), yet responders often reject unfair offers. This gap between predictions and behavior reveals that fairness concerns, equity sensitivity, and social punishment shape economic decisions.