Meta-analysis of contingent valuation studies on air pollution-related morbidity risks

Benefits of reduced morbidity are important information for cost-benefit analyses of air pollution control policies. With an increasing number of morbidity valuation studies, policymakers are facing some difficulty handling the accumulated information. This article uses a meta-analysis to attain insights from the literature on economic valuation of short-term health effects due to air pollution. Sixteen available contingent valuation studies on morbidity risk valuation were pooled to identify the relations between willingness-to-pay (WTP) estimates and possible influential factors. The results indicate that health risk characteristics expressed in terms of severity and duration of illness, population characteristics (e.g., income and education), and study features affect individuals’ WTP to reduce or avoid a given morbidity. By controlling for these factors, a meta-regression-based function can be used to predict WTP values for use in benefit analyses of policy evaluation.