Water conservation through plumbing and nudging

In this paper, we investigate two solutions to urban water security challenges: plumbing and nudging. Using anonymized monthly billing data from 1.5 million accounts in Singapore over ten years, our staggered difference-in-differences estimates show that a nationwide Home Improvement Programme that improves the efficiency of plumbing reduces residential water consumption by 3.5%. This effect persists over a decade and is robust across population subgroups. Efficiency improvements could enhance the efficacy of other conservation polices and mitigate the effects of excessive heat, rainfall and air pollution. The savings from efficiency improvements on utility bills are small, but the increase in housing value exceeds the private cost of the Home Improvement Programme. However, an evaluation of a nationwide peer-comparison nudging programme finds no evidence of reduced water consumption. Overall, we show that plumbing improvements generate long-lasting effects on water conservation. Using monthly water billing data for 1.5 million accounts in Singapore, Agarwal et al. show that nationwide efficiency improvements reduce residential water use by 3.5% for at least ten years but find no evidence of benefits from a nationwide peer-comparison nudge.

Automated summary

This study examines the impact of plumbing efficiency improvements and nudging programs on urban water security. The findings suggest that plumbing improvements can lead to a 3.5% decrease in residential water consumption over a decade, while nudging programs do not show significant effects. Plumbing improvements have long-lasting effects on water conservation and can enhance the efficacy of other conservation policies.