Heterogeneous Responses to Social Norms for Water Conservation

Utilizing social norms is gaining momentum as a cost-effective mechanism to promote sustainable behavior. We analyze household water data from multiple pilot programs for a company that provides information campaigns containing social comparisons of water use and personalized conservation recommendations in order to reduce household water consumption. We find significant treatment effect heterogeneity across the distribution of consumption and environmental attitudes. In the two pilots with a full year of data one utility achieves savings of 6.5%; while the other in aggregate achieved limited conservation gains. Heterogeneity based on the distribution of consumption is more important in the utility with significant savings, with the highest users saving the most water. In contrast ideology appears to be more important in the utility with an insignificant average treatment effect with dis-savings for those with very low environmental preferences and strong savings for the most environmentally-conscious. Inter-regional ideology may play an critical role since the utility with significant savings is in a much "greener" community, whereas intra-utility ideology is influential in conservative areas. We caution interpretation of the results, particularly for Utility B, as the data are still incomplete.