Ulric B. and Evelyn L. Bray Social Sciences Seminar

Abstract: I develop a theory in which the distribution of cultural traits and institutions co- evolve through a political multiplier : as more individuals adopt a trait, they support policies aligned with it, incentivizing others to adopt the trait, and leading politicians to propose even more aligned policies. This feedback loop can generate multiple stable equilibria, and the stronger the multiplier, the further apart they are. Several standard mechanisms from political and social economics amplify the multiplier. Information is aggregated through the political process and diffused via public signals rather than through decentralized social networks, allowing a temporary shock to trigger a rapid, long-lasting shift from one stable equilibrium to another. The model sheds light on Quebec's sudden secularization, the "Quiet Revolution." Combining 58 historical polls, I document that Quebec went from Canada's most to least religious province in under two decades after 1960, and show that existing theories cannot account for this striking pattern. I argue that Quebec's distinctive integration of church and state gave public institutions substantial influence over religiosity, producing a strong multiplier and multiple equilibria there—but not in the rest of Canada—thus leaving it susceptible to an equilibrium shift. I find support for three additional predictions of the model, and argue that a similar mechanism drove rapid secularization in the Netherlands and Ireland.