The impact of attitudes and behavioral costs on environmental behavior: A natural experiment on household waste recycling

Numerous studies have shown the importance of incentives as well as of attitudes in explaining pro-environmental behavior. Reported attitude effects, however, are generally rather small and exhibit considerable variation among studies. Different theoretical perspectives can account for this finding: whereas theories of rational action suggest additive effects of costs and attitudes, the low-cost hypothesis and dual-process theories imply interaction effects - in different directions, resulting from different mechanisms. The present study tries to overcome the shortcomings of past research by using advanced statistical methods to test competitive hypotheses in the context of post-consumer waste recycling. We utilize data from a natural experiment on recycling participation in Cologne/Germany (n = 1882) in which the incentive structure for recycling changed due to the conversion of the recycling scheme from a drop-off system to curbside collection. In order to avoid self-selection bias, we conducted pre- and post-treatment surveys and applied conditional fixed-effects regression models. We found that curbside collection had a strong impact on recycling participation and attitudes had a moderate effect. The interaction is negative but statistically insignificant. Our findings contradict the low-cost hypothesis and provide some evidence that environmental concerns moderate the effect of the recycling scheme. We cannot, however, reject the rational choice proposition of mere additive effects.