We investigate the long-run effects of cooling on conflict. We construct a geo-referenced and digitized database of conflicts in Europe, North Africa, and the Near East from 1400-1900, which we merge with historical temperature data. We show that cooling is associated with increased conflict....

Why do some leaders invest in significant nation-building policies and others do not? Why does nation-building occur at certain junctures in time and not others? In our research, we investigate what motivates leaders to nation build. We argue that threats to their regime motivate rulers to...

We consider the distribution of economic activity within a country in light of three leading theories - increasing returns, random growth, and locational fundamentals. To do so, we examine the distribution of regional population in Japan from the Stone Age to the modern era. We also consider the...

Within-country ethnic diversity in high-wage immigrant nations is driven by long distance migration. This paper documents the migration-diversity connection for the first global century before 1914 and the second global century after 1950. It distinguishes between ethnic diversity among the...