Tools- of Changes

Interventions Based on Social Comparisons or Financial Incentives Most Effective

This second-order meta-analysis found that the studied interventions increased associated environmental behaviors by 2% to 12%. Social comparisons and financial approaches, followed closely by appeals and commitment strategies, were the most effective interventions while education and feedback were the least effective.

Results from a second-order meta-analysis, including 10 meta-analyses and a total of 430 primary studies, show that pro-environmental behaviors increased by 2 to 12 percentage points compared to what would have been expected without treatment. Social comparison and financial approaches were the most effective tools, while information and feedback were the least effective. 

Interventions targeting littering showed by far the strongest effects . Those promoting recycling, conservation, and consumption behaviors were less effective but statistically significant. Those interventions targeting transportation behaviors had the smallest effects.