From Stephen Haber and Victor Menaldo:

Why have some countries remained obstinately authoritarian despite repeated waves of democratization while others have exhibited uninterrupted democracy? This paper explores the emergence and persistence of authoritarianism and democracy. We argue that settled agriculture requires moderate levels of precipitation, and that settled agriculture eventually gave birth to the fundamental institutions that under-gird today’s stable democracies. Although all of the world’s societies were initially tribal, the bonds of tribalism weakened in places where the surpluses associated with settled agriculture gave rise to trade, social differentiation, and taxation. In turn, the economies of scale required to efficiently administer trade and taxes meant that feudalism was eventually replaced by the modern territorial state, which favored the initial emergence of representative institutions in Western Europe. Subsequently, when these initial territorial states set out to conquer regions populated by tribal peoples, the institutions that could emerge in those conquered areas again reflected nature’s constraints. An instrumental variables approach demonstrates that while low levels of rainfall cause persistent autocracy and high levels of rainfall strongly favor it as well, moderate rainfall supports stable democracy. This econometric strategy also shows that rainfall works through the institutions of the modern territorial state borne from settled agriculture, institutions that are proxied for by low levels of contemporary tribalism.

For the pointer I thank www.bookforum.com.