What Causes Heterogeneous Responses to Social Comparison Messages for Water Conservation

Social comparisons for water conservation are often implemented in conjunction with a broader set of drought management policies. We investigate the interaction of social comparisons with prior responses to voluntary appeals for water conservation using a large-scale field experiment in Reno, Nevada. We develop a new social comparison framed as performance toward a conservation goal in contrast to the traditional comparison made in gallons. Our new social comparison decouples the performance relative to the peer group from baseline water use, allowing us to investigate the role of the peer comparison independently from baseline water use. Using a traditional and our new social comparison, we investigate prior conservation and baseline water use as drivers of heterogeneous response to social comparisons. Baseline water drives treatment heterogeneity in the traditional social comparison, while prior conservation drives treatment heterogeneity the new social comparison. The results indicate that under-performance relative one’s peers is critical for generating water conservation. Simple targeting of both types of social comparisons can increase aggregate savings by 38% because our new social comparison generates conservation among a different set of households compared to the traditional social comparison.