This is the question that Todd Rogers and I explore in our paper, “Persistence: How Treatment Effects Persist After Interventions Stop”, published in Policy Insights from the Behavioral and Brain Sciences. We propose a framework for understanding how and when interventions may lead to persistent behavior change. Specifically, we identify four “pathways”, or features of interventions, that may explain why some interventions are successful at generating persistent behavior changes. These pathways include (1) habit formation, (2) changing what or how people think, (3) changing future costs, and (4) external reinforcement
Habit formation occurs when an intervention causes people to repeat a behavior over and over again until they eventually perform the behavior automatically, without any continuing influence from the intervention. It could be that the Opower reports initially made people pay more attention to turning off lights when leaving a room, and over time they developed a habit of turning off lights, which continued even after the Opower reports stopped.
The second pathway works by changing what or how people think. People may fail to change their behavior because they hold an incorrect belief, because they don’t see themselves in a particular way, or because of the way they interpret information. If an intervention is able to change what people believe about themselves or about the world, or if an intervention changes how people interpret their experiences, then it may lead to persistent behavior change. For example, people who received the Opower mailings may have learned that they were not as energy efficient as they initially thought, which made them take steps to use less energy. Alternatively, the Opower mailings may have made people use their air conditioning less, but instead of interpreting a warmer house as uncomfortable, these people may have interpreted the warmth as a positive sign that they were saving electricity. Thus, they may have continued to use less energy going forward.