The Colonial Origins of Comparative Development: An Investigation of the Settler Mortality Data

In a seminal contribution, Acemoglu, Johnson, and Robinson (2001) evaluate the effect of property rights institutions on national income using estimated mortality rates of early European settlers as an instrument for the risk of capital expropriation. Returning to their original sources, I find the settler mortality data suffer from a number of inconsistencies, comparability problems, and questionable geographic assignments. When various methods are used to deal with these issues, the first-stage relationship between mortality and expropriation risk is no longer robust and typically insignificant. Consequently instrumental variable estimates are unreliable and suffer from weak instrument pathologies.