["Journal of Applied Social Psychology, EarlyView. ", "\nABSTRACT\nProsocial campaigns frequently rely on the symbolic value of participation, particularly when actions are publicly observable and function as social signals of altruism and moral identity. Although organizations often introduce personal economic incentives to increase engagement, such incentives may change the anticipated social meaning of participation because they provide observers with a plausible self‐interested explanation for the behavior. We propose that this change in anticipated social meaning reduces the perceived external symbolic value of participation, defined as the extent to which individuals believe that participating in the campaign will signal altruism to others, which in turn decreases willingness to participate. Across three studies, we show that adding a personal economic incentive reduces participation intentions by weakening perceived external symbolic value. Study 1 established this effect in a blood donation context and confirmed mediation through perceived external symbolic value. Study 2 provided process‐consistent evidence by showing that the effect is stronger among individuals high in impression management motivation in a cause‐linked consumption context. Study 3 replicated the effect in a green consumption context and showed that economic incentives reduced both external and internal symbolic value, but only the external pathway was amplified by impression management motivation. These findings show that economic incentives can undermine prosocial participation by changing the anticipated social meaning and weakening its external symbolic value.\n"]