Woodsy the optimal owl: Environmental campaigns, norms, and implications for public goods policy

Norms regarding private provision of a public good (e.g. cutting down on energy use, not littering) can affect the marginal gains from contributing to a public good and therefore people's decisions about contributing to the public good. A model is proposed in which norms of private contributions to a public good can be influenced by public policy, and these norms affect people's self-image, which derives from a comparison of one's own contribution with the norm contribution. In this context, we examine the conditions under which private contributions to a public good are efficient, and the conditions under which policy affecting these norms improves social welfare. We find that (1) a benevolent social planner who fails to account for private provision norms will underprovide the public good, and (2) public policy that attempts to raise the norm contribution of private provision can increase social welfare if the effect of raising the norm does not have an extreme negative effect – either extremely small or extremely large – on peoples' self-image.