Motivational Crowding in Payments for Ecosystem Service Schemes: a Global Systematic Review

We contribute to the growing body of literature on the ecological and socio-psychological impacts of providing payments as rewards for conservation. We conducted a systematic review of 74 payments for ecosystem services (PES) schemes and identified contextual factors that correlate with psychological mechanisms that enhance ("crowd-in") or erode ("crowd-out") autonomous motivation. Such indicators of crowding-in were more likely when schemes empowered local participants, provided in-kind non-monetary community benefits, and aimed to foster feelings of autonomy. Schemes that thwarted feelings of autonomy correlated with indicators of motivational crowding-out. Although motivational crowding had no effect on ecological success, indicators of crowding-in positively predicted social success (chi 2 = 8.60, n = 48, p = 0.003) and crowding-out negatively predicted social success (chi 2 = 9.59, n = 47, p = 0.002). Compared to past studies highlighting the negative impacts of extrinsic rewards on autonomous motivation, our study provides a more nuanced perspective and demonstrates that extrinsic incentives such as payments can promote crowding-in of autonomous motivation if schemes are designed equitably and provide opportunities for autonomous decision-making. Our study demonstrates how the application of psychological theories can contribute to the design of fair and effective PES schemes.