We propose an original model of human capital investments after leaving school in which individuals di¤er in their initial human capital obtained at school, their rate of return, their costs of human capital investments and their terminal values of human capital at a …xed date in the future. We derive a tractable reduced form Mincerian model of log earnings pro…les along the life cycle which is written as a linear factor model in which levels, growth and curvature of earnings pro…les are individual-speci…c. Using panel data from a single cohort of French male wage earners observed over a long span of 30 years, a random e¤ect model is estimated …rst by pseudo maximum likelihood methods. This step is followed by a simple second step …xed e¤ect method by which individual-speci…c structural parameters are estimated. This allows us to test restrictions, compute counterfactual pro…les and evaluate how earnings inequality over the life-cycle is a¤ected by changes in structural parameters. Under some conditions, even small changes in life expectancy seem to imply large changes in earnings inequality.JEL Codes: C33, D91, I24, J24, J31