Is it a story of early secularization?:
This research shows that secularization accounts for the early decline in fertility in eighteenth-century France. The demographic transition, a turning point in history and an essential condition for development, took hold in France first, before the French Revolution and more than a century earlier than in any other country. Why it happened so early is, according to Robert Darnton, one of the “big questions of history” because it challenges historical and economic interpretations and because of data limitations at the time. I comprehensively document the decline in fertility and its timing using a novel crowdsourced genealogical dataset. Then, I document an important process of secularization at the time. Using census data available in the nineteenth century, I show a strong association between secularization and the timing of the transition. Finally, I leverage the genealogies to account for unobserved pre-existing, geographic, and institutional differences by studying individuals before and after the onset of the transition and exploiting the choices of second-generation migrants.