Exploring the change in the heterogeneity of public preferences for air quality improvement policies before and after the COVID-19 pandemic: comparative results from latent class model analysis

In addition to the deadly effects of the COVID-19 pandemic, positive changes have been made in air quality. It is important for decision-makers to know whether people’s preferences change as the environment changes. This study tests the stability of public’s preferences and willingness to pay (WTP) for air quality improvement before and after the COVID-19 pandemic, using a choice experiment. To explore the determinants of the public’s preference heterogeneity for air quality improvement, we introduced the risk perception psychological factor and further compared the public’s preference heterogeneity before and after the COVID-19 pandemic based on a latent class model. The results suggest that the characteristics of respondents’ preference categories are similar in the face of a public health crisis and an uncertain future, and the heterogeneous preference of respondents for air quality improvement before the COVID-19 pandemic (2019) and after the COVID-19 pandemic (2021) which can be described in terms of three classes: “sensation preferable,” “health preferable,” and “price sensitive.” However, the sources of influencing preference heterogeneity before and after the COVID-19 pandemic are different, which are reflected in risk perception and socio-economic characteristic variables. After the COVID-19 pandemic, females with stronger perceived risk effects and lower acceptability of air pollution will pay more attention to the health attributes of air quality improvements. The results also reveal that respondents show different WTP for air quality improvement attributes, with respondents before the COVID-19 pandemic showing higher WTP than those after. The contribution of this study is to provide theoretical insights to explore the effects of stability of public preferences in the context of public health emergencies, and to provide valuable guidance for policy makers to formulate governance measures in line with public demands.