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

Behavioral policy often aims at overcoming barriers like imperfect information and limited attention that contribute to suboptimal consumer decisions. When multiple barriers are present, a single intervention that does not overcome all barriers simultaneously may fail to unfold its full potential. We conduct a three-month randomized field experiment on energy conservation in a resource-intensive everyday activity, using two different interventions. Home energy reports fail to reduce energy use despite achieving significant knowledge gains; real-time feedback induces considerable conservation effects. Strikingly, combining both interventions boosts these effects by over 50%. This showcases how barrier multiplicity can generate complementarities in behavioral interventions.