Can guilt really be a good thing when it comes to the choices we make, and can ethical — namely, “green” — behavior be a bad thing? George Monbiot recently wrote a post on Guardian News about green buying habits and their lingering effects on the moral psyche of the public. He mentioned a recent study released by the University of Toronto, “Do Green Products Make Us Better People?”

The study provides evidence that consumer choices — in this case, choosing green versus conventional products — affect not only price and other economic factors, but they affect social and moral attitudes as well. The authors, Nina Mazar and Chen-Bo Zhong, argue that buying green products, to which people attach a high social and moral value, actually produces a licensing effect: Those who behave in a nominally ethical and pro-social way in one instance will be less likely to regulate their subsequent behaviors. Buying green products establishes moral credentials, and this can lead to less ethical behavior in other areas — essentially, instilling in some people’s minds the idea that they can act more selfishly than before they performed the instance of ethical behavior.

The authors performed three experiments, one of which demonstrates the licensing effect in action: Participants who purchased green products were shown to lie, cheat, and steal more often. The psychological term “licensing effect” is, in my mind, analogous to the economic concept of “moral hazard,” which characterizes a situation in which an economic actor behaves differently when he is partially insulated from a risk than he would if he were fully exposed to it. When a person purchases car insurance, he may feel that he has purchased a “license” to drive more dangerously than before, to some degree, because of the compensatory reassurance that insurance provides. The psychological licensing effect may produce an impact on the public that is similar to that of economic moral hazard.

We may not be able to alter our psychology, but structural incentives can be changed. Monbiot’s Guardian piece mentions that we are living in a consumer democracy, and in such a system some people hold more “votes” than others. Those who possess disproportionately more votes are less inclined to change a system that has served them well, which ultimately means that those seeking change must look to a different mechanism, such as the political process.

These insights into human nature, and their potential implications, should be kept in mind as public policy is developed. Missouri has joined the ranks of many other states by instituting green legislation, such as a 2008 bill pertaining to green cleaning in schools, which the governor signed into law only after altering the legislation so that it would suggest guidelines and recommendations rather than mandate requirements for green cleaning. The licensing effect ties into this as well: A suggestion to behave responsibly may be more likely to result in moral credentials that justify irresponsible behavior elsewhere than if that behavior were mandated. This is not to suggest that policymakers should always use mandates, but the potential unintended consequences are worth thinking about.