Measuring public support towards different clean air targets in China

• Public support for stricter air quality targets increased significantly. • Subjective cognitions, not actual pollution levels, influenced WTP decisions. • Distinct subjective factors influenced different stages of WTP decisions. • Pessimistic cognitive biases substantially reduced public support willingness. Following remarkable achievements in air quality improvement, China has transitioned into a period of relatively low pollution levels, promoting discussions on further upgrading air quality standards. Effective policy-making depends not only on cost-effectiveness but also heavily on the public’s willingness to support such initiatives. Previous studies on willingness-to-pay (WTP) inadequately distinguished between the impacts of objective pollution levels and subjective cognitions, as well as how the cognitive relationships formed by these two factors affect WTP decisions. This study examines public willingness to support two different air quality improvement scenarios and investigates the underlying mechanisms influencing WTP decisions. Utilizing nationwide survey data from 7457 Chinese respondents and employing a two-part regression model, we found the average WTP to reduce PM 2.5 concentrations by 10 % (below 30 µg/m³) and to achieve levels below 5 µg/m³ were 277 and 295 CNY, respectively. Residents demonstrated significantly greater participation willingness and contribute higher amounts when presented with stricter air quality targets ( p < 0.05). Subjective cognitions, rather than objective pollution levels, primarily shape WTP through two distinct pathways: external factors (e.g., trust in government) influence initial participation willingness, while internal factors (e.g., perceived risk control) determine payment amounts. Additionally, pessimistic cognitive biases- low acceptance of air quality despite low pollution levels- significantly reduced individuals' likelihood of contributing ( p < 0.05). Our findings highlight distinct cognitive mechanisms underlying WTP decisions, suggesting tailored strategies to encourage collective action to further improve air quality and overcome pessimistic biases.