Can payments-for-ecosystem-services change social norms?

Exposure to economic incentives such as payments for ecosystem services (PES) can change intrinsic motivations to act pro-environmentally. These so-called crowding effects in PES have been shown to affect pro-environmental behavior of PES-receivers. It is, however, unclear if social norms toward pro-environmental behavior are also susceptible to crowding effects in PES and how these changes could influence pro-environmental behavior in the larger population. We design and implement a modified dictator game with Costa Rican oil palm smallholders to test if crowding effects can change social norms by affecting injunctive normative beliefs of PES-receivers and subsequently the pro-environmental behavior of non-PES-receivers through peer influence. Our results indicate that next to crowding-in pro-environmental behavior of PES-receivers, PES also improve PES-receivers' injunctive normative beliefs toward the behavior. Although we cannot link this improvement to an increase in pro-environmental behavior in non-PES-receivers, peer-to-peer communication of injunctive normative beliefs against pro-environmental behavior does reduce non-PES-receivers' pro-environmental behavior. Jointly, these effects highlight the potential of crowding effects in PES to change social norms.