We consider economic development of Sub-Saharan Africa from the perspective of slow convergence of productivity, both across sectors and across firms within sectors. Why have “productivity enclaves”, islands of high productivity in a sea of smaller low-productivity firms, not diffused more rapidly? We summarize and analyze three sets of factors: First, the poor business climate, which constrains the allocation of production factors between sectors and firms. Second, the complex political economy of business-government relations in Africa’s small economies. Third, the distribution of firm capabilities. The roots of these factors lie in Africa’s geography and its distinctive history, including the legacy of its colonial period on state formation and market structure.