Education, child nutrition, adult health/nutrition, and labor mobility are critical factors in achievingrecent sustained growth in factor productivity. To compare the contribution of these four human capital inputs, an expanded specification of the wage function is estimated from household (LSMS) surveys of Côte d'Ivoire and Ghana. Specification tests assess whether the human capital inputs are exogenous, and instrumental variable techniques are used to estimate the wage function. Smallerpanels from Côte d'Ivoire imply the magnitude of measurement error in the human capital inputs and provide more efficient instruments to estimate the wage equation. It is concluded that weight-for-height and height are endogenous, particularly prone to measurement error, and heterogeneous in their effects on wages. Overall returns to these four forms of human capital are similar within each country for men and women, but education and migration returns are higher in the more rapidly growing Côte d'Ivoire, and the wage effects of child nutrition proxied by height are greater in the poorer, more malnourished Ghana.