Financial and prosocial incentives promote pro-environmental behavior in a consequential laboratory task

Incentives are a popular tool for fostering pro-environmental behavior. However, it is still largely unknown which types of incentives are most effective during incentive implementation and beyond incentive discontinuation. One likely reason for this is that incentives are often tested in noisy field settings where controlled comparisons and longitudinal assessments are difficult. In this study, we address this limitation by studying incentive effects on consequential pro-environmental behavior in the laboratory. In a preregistered experiment, N=238 participants were repeatedly given the choice to save actual energy at a real waiting-time cost in the Pro-Environmental Behavior Task (PEBT). Incentivizing the energy-saving option with a 5-cent bonus payment led to a significant increase in pro-environmental behavior compared to a no-incentive control group (d=0.68). Incentivizing the energy-saving option with a 5-cent donation to charity had a smaller, but still significant effect (d=0.28). The difference between the incentive conditions was also significant (d=0.41). Group differences disappeared in a follow-up experimental session that was completed without incentives. These data illustrate the (temporally limited) effectiveness of financial and prosocial incentives and the possibility of studying incentive effects on actual pro-environmental behavior in the laboratory.