Complementarities in Behavioral Interventions Evidence from a Field Experiment on Energy Conservation

Behavioral policy often aims at overcoming biases due to, e.g., imperfect information or inattention. When bias arises from multiple sources, interventions that target different sources may be complements: each intervention becomes more effective when combined with another. We test this in a field experiment on energy conservation in a resource-intensive everyday activity (showering). One intervention, shower energy reports, primarily improves knowledge about environmental impacts; another intervention, realtime feedback, primarily increases salience of resource use. While only the latter reduced energy consumption significantly when implemented in isolation, combining both interventions boosted this conservation effect by over 50%, indicating a striking complementarity