There is a fascinating empirical sub-literature on the long-term impact of slave raiding in Africa that suggests that slave raiding had a greater negative impact on African development than colonialism. However, there are some analytical problems. The sub-literature recognizes the difference between slave raiding (estimated by the number of slaves exported from various places) and slavery in Africa (estimated by the proportion of a current state overlapping with historical slave labor practice) but has made no effort to untangle their possible different effects. Another problem is that the literature on colonialism has become more sophisticated recently with elaborate theories of how colonial impacts varied. It is one thing to operationalize colonial effect by whether or not a colony existed and for how long. It is another to assess how slavery shaped colonial differences. A third problem is that while a number of developmental processes have been examined, autocratization tends not to be one of them – perhaps because the sub-literature is predominately characterized by econometric analyses with greater interest in economic growth variance. In other words, new arguments about how colonial circumstances varied and the absence of autocracy as a dependent variable invite a renewed inquiry into the relative impacts of slavery and colonialism.in the African experience over the past 500 years. We regress historical data on slave raiding and slavery into Lee and Paine’s (2024) model of colonial origins of democracy and dictatorship and in turn to contemporary VDem data on autocratic variation in sub-Saharan Africa.