SOCIAL AND REPUTATIONAL DRIVERS OF SUNK-COST SENSITIVITY IN INDIVIDUAL AND COLLECTIVE DECISION-MAKING

Why do people stick with failing plans after investing resources? This dissertation argues that sunk-cost behavior is shaped more by social pressures than by cognitive bias. Across three preregistered, “waste-free” studies, I show that people persist to protect reputation and relationships—especially when others have invested or when commitment signals reliability. When social audiences or obligations disappear, escalation fades. Additional chapters show that voters reward decision-makers who stay committed and develop a framework explaining both cognitive and social costs of changing course. Together, the work explains when sunk costs bind—and when they don’t.