Stated benefits from urban afforestation in an arid city : a contingent valuation in Mexicali, Baja California, Mexico

The pervasiveness of particulate matter in arid cities has yet to be discussed and tackled. Given that urban trees have been documented to provide air-filtering and dry deposition services, this study documents the stated benefits from an urban afforestation scenario in Mexicali –an arid city located northwest Mexico at the US-Mexico border. Our double-bounded dichotomous contingent valuation protocol yields an estimated average annual willingness to pay (WTP) of USD 88 per household. Variations in the WTP are associated with perception of air quality and presence of respiratory symptoms in the respondent’s household. The smallest WTP (USD 75) is reported by respondents perceiving poor air quality in their neighborhood and with no household members affected by respiratory symptoms. In contrast, respondents perceiving good air quality and with at least one household member facing respiratory symptoms reported a WTP of USD 99. The average stated benefits represent around 0.8% of the annual household income