3.1. WTP across different vignettes
Figs. 1 and 2 show the boxplots of WTP estimates for air pollution and noise by countries respectively. Noticeable differences were observed regarding the WTP estimates across pollutants and countries. Table 2 presents the mean and median WTP estimates. WTP for the general risks of air pollution was higher than for noise, WTP to avoid specified effect for noise (severe annoyance) was higher than for air pollution (life expectancy), and WTP for the combined scenarios was similar for both pollutants. The country that provided the highest and the lowest WTP estimates for air pollution risks differed for each vignettes. For noise, Finland had the highest WTP estimates for all three vignettes, while the Netherlands provided the lowest (except for the specific effect).