Bennear and Olmstead have written The Impacts of the 'Right to Know': Information Disclosure and the Violation of Drinking Water Standards. The Abstract:
The 1996 Amendments to the Safe Drinking Water Act mandated that community drinking water systems issue annual consumer confidence reports (CCRs) to their customers. The CCRs must contain information on violations of drinking water regulations as well as information on the levels of contaminants in drinking water, even if these levels are below the regulatory limits. We examine whether the mandatory provision of information induced reductions in violations using panel data collected by the State of Massachusetts on drinking water violations by 498 community water systems from 1990-2003. We use several estimation strategies to isolate the causal effect of information disclosure on violations including panel data models, quantile regression, and regression discontinuity models. We find little evidence that the requirement to compile a CCR lowered violations. However, we do find some evidence that utilities that were required to mail their CCRs directly to customers violated standards less frequently after the CCR rule took effect. This result is intuitive in light of the likely pathways through which information disclosure is thought to affect the behavior of regulated entities. Because utilities were already required to report violations to the state, the utility itself does not learn much by compiling the data for the CCR. The CCR only impacts utility behavior if there is a political response to the findings, which is more likely when the public is made directly aware of violations by mail.