Ex-post evaluation of environmental decontamination plans on air quality in Chilean cities

This paper evaluates the impact of the Environmental Decontamination Plans (known as PDAs) on air quality in Chilean cities, for which the differences in differences method was used during the period between 2010 and 2017. The ex-post evaluation shows that the implementation of a PDA for PM₁₀ has no impact on the monthly concentrations of PM₁₀. However, the new PDAs for PM_2.5 (that were implemented starting in 2015) reduce the monthly concentrations of PM₁₀ by approximately 8 μg/m³, although they have not reduced the monthly concentrations of PM_2.5. Thus, it is concluded that the assumptions and scenarios used in the ex-ante evaluations to project the reduction of PM_2.5 concentrations in the PDAs are extremely optimistic in relation to their current contribution to improving air quality in Chile.