The impact of irrigation on democratization

There is a large variety of institutions and cultures around the world, and I find it fascinating to understand how they originated. The literature has shown that some of them have origins that go back very far, possibly all the way to the introduction of agriculture (Example 1 and example 2)

Jeanet Sinding Bentzen, Nicolai Kaarsen and Asger Moll Wingender discuss how irrigation has influenced the arrival of democracy, and in fact prevented it. They point out that this is not a story about irrigated versus rain-fed agriculture, but rather of areas where there was potential for irrigation versus the others. The story is as follows. Irrigation requires large investments and control of water sources, and allows the extraction of substantial rents. This is a perfect environment for a despot. This theory was advanced by Wittfogel in Oriental Despotism and was soundly criticized. But Sinding Bentzen, Kaarsen and Moll Wingender confirm that the theory holds water empirically. The fact that irrigation potential is crucial allows to avoid the reverse causality issue, as geographic factors are presumably exogenous to institutions, at least until man started having an impact on climate. What is fascinating is that this still has an impact today on the prevalence of democracy.