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Comparative Spill-Over And Degradation Effects Of Nudges And Boosts

This project compares two types of non-coercive and non-incentivizing policies that aim to change households’ energy and consumption behavior. It tests the comparative effectiveness, degradation and spill-over effects of these two policy types in a long-term, randomized field experiment.

Exeriors of buildings with people in front.
Consumer behavior is an important factor in household energy efficiency.


People often waste energy by running devices on standby rather than shutting them off. Various studies estimate the waste at about 8% of overall residential consumption. The goal of behavioral policies in this area is to decrease standby power, without coercing people or changing their incentives. A possible nudge for this purpose would be to fit power outlets with timing devices, with timer defaults set at 15 or 20 min, so that continuous users would regularly have to switch power back on, while standby power use is automatically stopped after the timer runs out. A boost, in contrast, would combine equipment fitting and competence training.

Currently, among non-incentivising and non-coercing policy interventions, Nudges have received most attention from policymakers and the public (Thaler & Sunstein 2008, Executive Order Using Behavioral Science Insights to Better Serve the American People, signed by President Obama on September 15th, 2015). Yet the insights from behavioral science are substantially richer and wider than the current focus on nudges would suggest.

We have provided a mechanistic analysis of these two policy types (Hertwig & Grüne-Yanoff 2016) and from this analysis have derived a number of hypotheses about the effectiveness of the respective policy types in different environments (Grüne-Yanoff, Machionni and Feufel 2016, Hertwig 2016). In particular, we hypothesize that boosts exhibit more spill-over effects, and are less prone to degradation, than nudges. In this project, we will test these hypotheses in the context of energy and resource consumption in residential homes.

Project description

This project compares two types of non-incentivizing, non-coercive behavioral policies that aim to affect residential end-use energy and resource efficiency. We will investigate the interventions’ effectiveness of bringing about the desired behavioral change, and are particularly interested in two dimensions: (i) the respective degradation of these policy types over time, and (ii) the respective-spill-over effects towards adjacent domains.

By degradation, we mean a systematic lessening of the intervention’s effectiveness when the intervention is continuously performed over an extended period of time under stable environmental conditions. For example, while many people initially choose a newly set default option, the attractiveness of this default option in many instances seems to decrease as people get used to it. By spill-over effects, we mean a systematic influence on behavior in domains different than the one intervened on. For example, improving a consumer’s electricity saving strategies might have an affect on her other energy saving strategies (e.g. heating), too.

The purpose of this project is twofold. First, we want to investigate effective interventions on end-use behavior in a realistic long-term field experiment. Second, we want to gather evidence for the effectiveness of different types of policy interventions, thus expanding the current discussion that we believe is often too narrowly focused on Nudges.


We test our theoretical hypotheses with data obtained from randomized field experiments in the Live-in Lab.