Monetary valuation of air quality improvement with the stated preference technique: A multi-pollutant perspective

Air pollution is an important global issue, and governments are making efforts to reduce air pollutant emissions. The elaborate calculation of the social costs of air pollution is essential for justifying the substantial public expenditure on air pollution control policies. This study aims to derive the monetary value of reducing different kinds of air pollutants through the public's willingness to pay (WTP). A choice experiment survey is conducted to examine the public perception of air quality improvement, and the collected stated preference data are analysed with the hierarchical Bayesian logit model. The analysis results show that the public valuation of the emission reduction differs for individual pollutants. On average, the monetary value of one ton of emission reduction follows the order of PM_2.5, PM₁₀, SO_x, TSP, NO_x, and VOC. Based on the elicited WTP, the economic feasibility of the two air pollutant reduction plans of the South Korean Government is assessed. The benefit-to-cost ratio of the plans is 0.61 and 0.66, respectively, based on the mean WTP, indicating that they are not economically feasible at the moment. Implications for the efficient budget allocation of air pollution control policies are provided based on the results.