This project aims at identifying the causal effect of curbside collection on households' propensity to recycle by evaluating the implementation of a curbside-recycling program for paper and packaging in Cologne, Germany. Using propensity score matching and differences-in-differences estimation with individual-level panel data we estimate the curbside effect, its variation between types of recyclables and sociodemographic background variables, and its elasticity with regard to the distance to collection containers in the prior bring scheme condition. We argue that, in our setting, DD may be systematically upward biased due to the outcome variable being self-reported. While a triple-differences estimator effectively accounts for such bias, it may be systematically downward biased due to over-control. Accordingly, we combine both estimators to derive upper and lower bounds of the true effect. We find that a curbside scheme increases recycling participation by up to between 10 & 25 percentage points, depending on type of recyclable and initial distance. The results of our analysis therefore have important implications for effective and cost-efficient implementation of environmental protection policies in urban areas.
The project was conducted in cooperation with Henning Best (University of Kaiserslautern). Findings have been published in Environmental and Resource Economics.