Giacomo Benati, Federica Carugati, Gabriel Leon-Ablan

Abstract: The invention of writing was a major technological breakthrough, yet its adoption was highly uneven across the Ancient World. Using regression analysis on a new dataset of 219 archaeological sites from 4th millennium BCE Mesopotamia, we examine how environmental and institutional factors shaped this pattern. We find that following a regional aridity shock, polities ruled by religious elites were more likely to adopt true writing, while those led by secular elites tended to retain earlier record-keeping systems. Other explanations—such as complexity, prior technology, proximity to inventor, or network ties—account for little of the observed variation in adoption. We also show that climate shocks did not directly spur state capacity, challenging the view that writing spread to meet administrative needs.