Abstract
We study the emergence of extractive institutions induced by external military threats. Using the case of early modern Russia, we explore the consolidation of serfdom under the pressure of landholding military elites who gained political influence due to the prolonged struggle with steppe nomads. To contain nomadic raids, the Russian state erected defense lines on the southern frontier, and granted lands in the area to soldiers in charge of its defense. The soldiers could not farm while on defensive duties, nor could they compete in the market for peasant labor because the lands had been selected for their defensive rather than agricultural value. The system was therefore only sustainable by gradually binding peasants to the land. Using newly digitized 17th century population data, we show a higher prevalence of serfs and military landholders in districts on the defense line. We also find a higher prevalence of small estates -- up to 25 serf households -- sufficient to support a warrior and his family. Placebo tests reveal that these patterns do not hold for non-serf peasants and in other, defensively non-optimal, locations. To ensure causality, we develop a novel algorithm that reconstructs the optimal invasion routes for nomads and pinpoints the optimal location of the defense line using topographic data. Our results suggest that military considerations -- rather than the high land-labor ratio -- were among the key factors of serfdom formation. This sheds new light on the possible mechanisms of institutional divergence between Eastern and Western Europe in the early modern period.