Pro-Social Change for the Most Challenging : Marketing and Testing Harm Reduction for Conservation


This paper investigates the effectiveness of pursuing conservation goals by promoting harm reduction, a once controversial approach to health care that aims to reduce the harmful impacts of unhealthy behaviors without promoting full abstinence or stigmatizing said behaviors. Conservation proponents often heavily promote solutions more akin to full abstinence, which do not recognize the inherent preference trade-off the heaviest users face when giving up a behavior that may be harmful to the environment, such as driving a car, eating meat and dairy or watering a lawn. We employ two sequential field experiments to market and test effectiveness of a smart irrigation controller, a lawn watering efficiency device. This solution has an ex-ante lower expected impact on conservation than turf removal, the highest impact solution in this context, but is nevertheless more aligned with the preferences of the heaviest users. We show that marketing this preference-aligned solution induces the highest adoption among the heaviest irrigators and those previously disinclined to conserve. Given these compliance patterns, our interventions lead to large and long-lasting individual and social benefits: water savings from the device recover its cost in half a year and are of the magnitude of one household’s basic (indoor) water needs. We find no meaningful increase in water usage among those irrigating less and no evidence of reduced turf removal, suggesting that the harm reduction intervention grows, rather than cannibalizes, the adoption of water conservation alternatives. Our results underscore the importance of considering heterogeneous preferences when designing interventions aimed at fostering pro-social behaviors such as conservation and shed light on how to use marketing to engage the least pro-socially inclined