Follow the leader? Testing for the internalization of law

Abstract

The internalization of law is said to be a process that involves a change in people’s intrinsic motivation to act in accord with the law’s obligations, so that it is possible to observe imposed obligations become individual choices. We empirically test for this phenomenon by attempting to disentangle the impacts of a legal change (a 5-pence charge on the use of plastic bags) on intrinsic motivation and individual choice. We do so by measuring behaviors and attitudes before and after the legal change and by comparing the impacts across neighboring jurisdictions without the change. Using a difference-in-differences estimator, we find evidence for the internalization of the law. However, using mediation analysis, we find that internalization of the law explains only around 5–8 percent of the change in behavior—the rest being attributable to the direct effect of the charge.