[영문]Using matched employer-employee data from ten African countries, we examine the relationship between wages, worker supervision, and labor productivity in manufacturing. Wages increase with firm size for both production workers and supervisors. We develop a two-tier model of supervision that can account for this stylized fact and we fit the structural model to the data. We find a strong effect of both supervision and wages on effort and hence on labor productivity. Labor management in sub-Saharan Africa appears problematic, with much higher supervisor-to-worker ratios than elsewhere and a higher elasticity of effort with respect to supervision than in Morocco.