Prices, Devices, People, or Rules: The Relative Effectiveness of Policy Instruments in Water Conservation1

Abstract Water conservation policy is a natural laboratory for addressing general issues of relevance to policy analysis and public administration, particularly the relative effectiveness of policies in changing human behavior. Using multivariate regression analysis of a dataset comprised of more than 200,000 monthly observations of more than 19,000 household accounts over six years, this paper makes three main contributions. First, it contributes to the substantive area of water conservation policy by analyzing what works. Second, it contributes to our understanding of generic policy instruments. Third, it raises an important issue regarding standard assumptions about selection bias. The results support earlier work warning that offsetting behavior can negate engineering solutions to policy problems, but further indicate that adding communication to engineering solutions can create cooperation that overcomes offsetting behavior. They also provide evidence that appropriate regulation can be effective, and that pricing can be effective even when price elasticities of demand are low.