Political Institutions, Resources, and War: Theory and Evidence from Ancient Rome

Abstract

How does the size of the governing coalition affect the amount and type of violence in society? This paper combines models of the selectorate with stationary bandits to predict that larger coalitions substitute away from fighting for private goods (such as plunder) towards fighting for public goods (such as defense), but does not necessarily reduce the overall scale of fighting. To test this idea, I empirically investigate how Rome's transition from Republic to Empire affected military patterns. I find that the Republic engaged in more battles overall and that Republican battles had more of a public good component. Overall, this paper furthers our empirical knowledge about the ancient world and brings the data to bear on contemporary debates about the causes of peace and war.

Keywords: War, Institutions, Rome, Land, Human Settlement, Coalition Size

JEL Classification: H56, H41, H42, N43, N53, P59