This paper analyses the relationship between educational attainment and the impact of professional training labour income and total output. It shows that there is theoretical support for the hypothesis that when there is an increase in the educational attainment of the beneficiaries of the professional training, there is a growth of this impact. This result has support from two approaches considered, the arbitrage approach and the standard microeconomics labour market demand approach. It is argues that under reasonable assumptions on the cost function, it is possible to face a trade of f between efficiency and fairness of a state promoted professional training policy. Empirical tests using data from Brazilian PLANFOR supports the relationship between educational attainment and the impact of training on labour income.