The willingness to pay for removing the microplastics in the ocean - The case of Seoul metropolitan area, South Korea

Microplastics - small plastic particles with less than 5 mm in diameter - in the ocean have become major social concerns among people since it has been found not only harmful to the marine eco-system but also human health. Then, there is an increase in the social demand for appropriate policy by the government. To prepare appropriate countermeasures, it is essential to estimate the environmental damage cost of microplastics in the ocean in advance. Therefore, this study estimates willingness to pay of residents in Seoul metropolitan area in South Korea for removing the microplastics to provide the quantitative information of the environmental damage cost of microplastics in the ocean. This study employed one-and-one-half-bound dichotomous choice with spike model to collect the WTP responses data. To deal with the outliers, we assumed that the distribution of WTP is the contaminated normal distribution, which is heavy-tailed in comparison to normal distribution used in previous studies. In addition, to deal with the numerous zero WTP responses, this study employs the Bayesian censoring regression with data augmentation method. The estimate of the average yearly WTP is KRW 2845.6 (USD 2.59). Additionally, total WTP of households in Seoul metropolitan area was KRW 10.8 billion (USD 9.80 million) annually.