Norm-based feedback on household waste: Large-scale field experiments in two Swedish municipalities

Abstract

We conduct two large-scale randomized controlled trials to produce the first evidence that Home Energy Report-type norm feedback letters can be used to reduce household waste. We explore several feedback variants, including a novel short-run dynamic norm that emphasizes ongoing changes in waste behavior. Waste reductions are on the order of 7%–12% for all treatments, substantially larger than usually found in the energy or water domains. Effects are mostly driven by increased recycling of packaging and remain largely intact a year after the intervention ended. Feedback is highly cost effective compared to alternative non-price waste policies. However, net social benefits depend on household preferences for receiving feedback, which we elicit in a valuation survey, and whether existing waste fees internalize the marginal social cost of waste.