This paper tests hypotheses on the causal effect of a reduction of behavioral cost on participation in household waste recycling. We use data from a natural experiment in Cologne, Germany and employ propensity score matching and conditional fixed effects regression to identify the treatment effect. The empirical data was collected in a panel survey in three city districts. Basis for the natural experiment is the decision of Cologne''s public administration to step by step implement a curbside collection scheme for household recyclable. In one of the districts, the traditional bring-scheme was replaced with a curbside scheme between the two panel waves. Using this data we can identify the causal effect of curbside collection, its variation between types of recyclables, and its elasticity with regard to the distance to collection containers in the bring-scheme condition. First results indicate that a curbside scheme is most efficient for plastics, metal cans and packaging and less efficient for paper. Furthermore, the effects of an implementation of a curbside scheme appear to be stronger when the initial distance to a collection container was greater. The results of our causal analysis therefore have important implications for a effective yet cost-efficient implementation of environmental protection policies.
