The Legacy of the Slave Trade: Towards Identifying the Causal Impact of Mistrust in Medicine on Demand for Vaccination in Sub-Saharan Africa

There is a large body of anecdotal evidence from sub-Saharan Africa of widespread medical distrust leading to health program failures. In this paper, to isolate an exogenous variation in trust in medicine to explain contemporary health demand in sub-Saharan Africa, we rely on a widespread historical shock: the slave trade. We combine \possessivecite{NunnWantchekon2011} historical data on the slave trade by ethnic group with individual-level data, geolocated at the district level, from the 2010-2014 Demographic and Health Surveys (DHS) to examine the reduced-form relationship between ancestors’ exposure to the slave trade and children vaccination status against measles. Exploiting variations both within countries and districts, we find that children from mothers whose ancestors were exposed to the slave trade are less likely to be vaccinated. The size of the effect offsets or even dominates the ones obtained for standard determinants of health demand, such as education or revenue. Evidence from a variety of identification strategies shows that the slave trade affects demand for vaccination only through trust in medicine. We then provide explanations for the persistent effect of the slave trade. Consistent with the economic approach, we identify religious affiliations and matrilineal lineage systems as important cultural transmission mechanisms. Consistent with the evolutionary anthropology approach, we point to the similarity of the environment across generations due to colonial and contemporaneous abusive medical treatments to explain persistence of optimal mistrusting behavior.