Catholic Censorship and the Demise of Knowledge Production in Early Modern Italy

Censorship makes new ideas less available to others, but also reduces the share of people choosing to develop non-compliant ideas. We propose a new method to measure the effect of censorship on knowledge growth, accounting for the agents' choice between compliant and non-compliant occupations. We apply our method to the Catholic Church's censorship of books written by members of Italian universities and academies over the period 1400-1750. We highlight two new facts: once censorship was introduced, censored authors were of better quality than the non-censored authors, but this gap shrank over time, and the intensity of censorship decreased over time. These facts are used to identify the deep parameters of a novel endogenous growth model linking censorship to knowledge diffusion and occupational choice. We conclude that censorship reduced by 34% the average log publication per scholar in Italy, while adverse macroeoconomic processes are responsible for another 9% reduction. Interestingly, the induced reallocation of talents towards compliant activities explains half the effect of censorship.