Norms and norm change - driven by social preferences and Kantian morality

Norms indicate which behaviors are commonly expected and/or considered to be morally right. We examine how such norms come about and change by modeling a population of individuals with preferences – found elsewhere to be evolutionarily founded – combining ma-terial self-interest, Kantian moral concerns, and attitudes towards being materially ahead and behind others. The individuals interact in a public goods game. We identify conditions on preferences and beliefs which promote, respectively hamper, spontaneous norm change. Cru-cially, an individual’s preferences and beliefs about the material benefits uniquely determines her threshold for collective behavior: s/he contributes if and only if sufficiently many others do so. However, those with sufficiently strong Kantian concerns contribute regardless.