Social Norms and Social Change

We study how social norms affect social change in a setting where people have both internal motivations and a desire to conform. We distinguish two kinds of internal motivations: common values in which people wish to behave consistent with some evolving, uncertain ground truth and private values in which individuals genuinely disagree about proper behavior for non-informational reasons. In both settings aggregate behavior changes more slowly than beliefs about proper behavior, and increased information reduces such inertia. Inertia is a more severe problem, but information is more effective, when values are common rather than private. In this common-values setting, we identify conditions under which increased information leads to a normative improvement. Finally, we elucidate empirical implications for the relationships between measures of attitudes, behavior, and descriptive norms. The average perceived descriptive norm is lower than the average action which is lower than the average belief about the right action (injunctive norm). Thus, behavioral forecasts based on survey answers about perceived descriptive or injunctive norms are under- and over-estimates, respectively.