It’s about time: Increasing climate support by changing the timing of incentives, not the incentives themselves

To design impactful climate policies, we need evidence-based strategies for how to reliably increase pro-environmental behavior. The current research tested whether donations to a climate organization could be increased by changing the timing of incentives, without changing the incentives themselves. In a high-powered and pre-registered experiment (N = 2,013), we assessed whether the proportion of a personal reward people donated to a top-rated climate organization (Clean Air Task Force) was influenced by simple changes in timing. We tested this in the United States, a high-emitting country where climate support is politically polarized. Using an incentivized dictator game in a 2x2 between-subjects experiment, we manipulated the timing of the personal reward to participants (immediate vs. 4-month delay) and the timing of the donation to the organization (immediate vs. 4-month delay). Consistent with our general hypotheses, participants donated significantly more to the climate organization when the personal reward would be paid out with a delay rather than immediately (5 percentage points), and conversely, they also donated significantly more when the donation to the climate organization would be paid out immediately rather than with a delay (3 percentage points). Left-leaning liberals and those with stronger climate change beliefs donated more money than right-leaning conservatives and people with weaker climate change beliefs, but the causal timing effect was not moderated by left-right political orientation or belief strength. If all our participant choices had been implemented, the strongest intervention difference would have resulted in an estimated 344-ton reduction in CO2.