Uncovering the Impacts of Social Comparative Information on Water Saving Behavior Among Urban Residents: A Field Experiment in China

Abstract

In recent years, social comparison information has been regarded as an effective behavioral intervention tool that can encourage individuals to adopt more sustainable behaviors. However, the specific mechanisms through which social comparison information impacts practical applications remain unclear. Grounded in the social comparison theory within behavioral economics, this paper investigates the application of social comparison information in water saving behavior interventions. To this end, we conducted a large-scale field experiment in China over a period of 10 months, using a difference-in-differences model to rigorously assess the effects of eight types of social comparison information on water-saving behaviors among urban residents. The aim is to explore how spatial distance, monetary framing, horizontal comparisons, and historical comparisons influence the effectiveness of social comparison information in promoting water conservation. The findings reveal that the water-saving efficiency of social comparison information exhibits an inverted U-shaped trend, initially increasing and then decreasing with decreasing spatial distance of the comparison group, with the "apartment community comparison" being the most effective in encouraging water-saving behavior. Moreover, while there is no significant difference in the impact of monetary versus non-monetary framing of social comparison information on water conservation, monetary framing appears to somewhat diminish prosocial motivation. Additionally, social comparison information outperforms historical comparisons, which showed no significant effect on water-saving behavior, even among low baseline users. This study provides vital policy implications for leveraging social comparison messages to enhance urban household water conservation efforts.