This thesis investigates the determinants of wages in Colombia, the wage differential between public and private workers and earnings dispersion for wage workers and the selfemployed between 1984-1994. It attempts to determine how important education and expenence are in determining individual earnings, emphasising the analysis of rates of return to education using the Mincerian framework. It also examines the importance of the human capital model in determining earnings, particularly for the self-employed. A model is developed in this case for an endogenous treatment of sectoral choice in order to correct for potential selectivity bias. Estimates are presented for the rates of return to education for both wage workers and the self-employed using data drawn from the "National Household Survey" in tcn Colombian cities, in June 1984, 1988, 1992 and 1994. Rates of return to education merit special attention for two principal reasons: firstly, previous studies in Colombia show a secular decline in the returns to education; secondly, changes in the relative demand for skilled/unskilled workers were anticipated after trade liberalisation and these changes may affect rates of return to education. This dissertation also examines the size of the public wage pay differential in the Colombian labour market during the period of structural adjustment. A further objective is to determine the extent to which it was affected by public sector reform. It is worth noting that the public sector wage differential has not been the subject of analysis in Colombia since 1983. Finally, wage distribution in Colombia during the structural adjustment is analysed. Debate in Colombia has focused on wage distribution. The latter is closely related to human capital and its market price, both of which have changed during the period. A chief aim of this dissertation consists in determining how the changes in the rates of return to education that occurred during structural adjustment explain the increased wage inequality observed during the early 90s.