We investigate the historical origins of mistrust within Africa. Combining contemporary household survey data with historic data on slave shipments by ethnic group, we show that individuals whose ancestors were heavily threatened by the slave trade today exhibit less trust in neighbors, family co-ethnics, and their local government. We confirm that the relationship is causal by instrumenting the historic intensity of the slave trade by the historic distance from the coast of the respondent’s ancestors, controlling for the respondent’s current distance from the coast. We undertake a number of falsification exercises, all of which suggest that the necessary exclusion restrictions are likely satisfied. We then show that much of the relationship between the slave trade and an individual’s level of trust today cannot be explained by the slave trade’s effect on factors external to the individual, such as domestic institutions or the legal environment. Instead, the evidence shows that a significant portion of the effects of the slave trade work through vertically transmitted factors that are internal to the individual, such as cultural norms of behavior, beliefs and values.
You can read the whole paper here. It's a great example of good political science: it is empirically rigorous, takes the question of causation seriously, incorporates elements of culture, and is morally engaged.
