摘要:This paper explores the issue of whether strict liability imposed on polluters hasserved to reduce uncontrolled releases of toxics into the environment. Strict liability shouldcreate additional incentives for firms to handle hazardous substances more carefully, thusreducing the future likelihood of uncontrolled releases of toxics. However, the size of theseincentives may vary according to the size of a firm's assets, since asset size is the ultimatelimit on a firm's liability. We are therefore interested to see whether imposing strict liabilityfor the cost of remediation at hazardous waste sites has encouraged firms to handle toxicmaterials more carefully and has uniformly reduced the incidence of toxic spills, or whetherthe effect is dependent on firm size and other factors.To answer these questions, we exploit the variation in state hazardous waste site lawsacross states and over time. We use data on accidents and spills involving hazardoussubstances coming from a comprehensive database of events reported to the US EPA undertheir Emergency Response Notification System (ERNS), and fit regressions relating thefrequency of spills of selected chemicals used in manufacturing to the type of liability in forcein a state. We control for the extent of manufacturing activity in the state, and include in theregression other program features that might alter firms' expected outlays in the event of anaccident, and thus affect firms' incentives to take care.Results vary with the chemical being analyzed. For some chemicals, such ashalogenated solvents, the presence of strict liability does not provide any additionalexplanatory power for the number of spills beyond what is achieved by the number ofestablishments and the sectoral composition of manufacturing. For other families ofchemicals (acids, ammonia and chlorine), we find that the impacts of manufacturing activitieson the number of spills in each state do vary systematically with the liability regime. Inparticular, it appears that under strict liability small firms are responsible for adisproportionate number of spills. Since strict liability states tend to have moremanufacturing firms, and more small manufacturing firms, these factors serve to increase thenumber of spills of these chemicals in strict liability states.