Understanding citizens' willingness to contribute to urban greening programs

Urban green is an essential component of livable and sustainable cities, providing benefits for the environment, human health, and well-being. In densely built city areas, planting street trees and installing green roofs and facades can lead to more equally distributed green infrastructure, for which it gained importance in urban planning. However, to achieve the desired effects, cities need to implement small-scale measures on a large scale, which requires broader urban restructuring and significant financial and political resources. Economic valuation can support this process by providing city governments with knowledge about citizens' support and preferences for greening policies. We use a choice experiment in the Austrian capital, Vienna, as part of a representative survey of 1,327 respondents. Using a Mixed Logit Model with correlated random parameters, the results show a clear preference for a greener city, while respondents express a higher marginal willingness to pay (WTP) for measures on streets (5.58 Euro/year) than on buildings (3.60 Euro/year) for change the density of green measures from rare to frequently. Introducing interactions with socioeconomic variables, selected attitudes, and neighborhood characteristics based on geo-referenced addresses, we find a positive correlation between a higher WTP and the characteristics of younger and more affluent residents, as well as citizens who suffer significantly from urban heat, use parks more regularly, and live in neighborhoods with relatively little urban greenery. Overall, the analysis proves valuable for estimating public support and facilitating comparisons between different greening options, contributing to a more informed and nuanced discussion in urban planning and policy.