Normative Ambiguity, Social Norms, and the Expressive Power of Law

Legal scholars have long debated whether law, through its expressive power, can influence prevailing social norms. Empirical studies inspired by this debate have focused on establishing the existence of an expressive power. However, this dichotomous perspective overlooks the nuances of the theoretical discourse regarding the conditions under which law, independent of any enforcement, can wield greater or lesser impact on social norms. This article employs a regression discontinuity design to examine the expressive power of the law in shaping social norms and measure its sensitivity to contextual factors. Using a preregistered incentivized experimental survey (N = 2913), we demonstrate that: (1) law, qua law, can indeed influence perceived social norms; and (2) this influence of the law is moderated by the normative clarity of the scenario. The law has the greatest impact on perceived norms in ambiguous situations; when additional normatively relevant information is provided, the expressive power of the law diminishes.