Social and environmental nudges and water usage: Evidence from a field experiment in Iran

We nudged households in Torbat Heydarieh, a city in Iran, with social comparison and public environmental messages to decrease water consumption. In the former treatment, we provided subjects with their actual water consumption compared to their neighborhood’s minimum and average consumption. In the latter one, we illustrated some facts about the water crisis in Iran and each individual’s potential role in dropping it. We also incorporated perceptions and attitudes of our subjects on water consumption, extracted from our survey, to control for their possible impacts. Our results show that the social comparison nudge lessens the daily water usage of each family member by about 30 percent. In contrast, a nudge with public environmental messages does not have any effect.