Hartog, J., Pereira, P. and Vieira, J. (2001). Changing returns to education in Portugal during the 1980s and early 1990s: OLS and quantile regression estimators Applied Economics, 33(8):1021--1037.

This paper examines the evolution of the returns to education in Portugal over the 1980s and early 1990s. The main {\textregistered} ndings indicate that the returns to education have increased, particularly after joining the European Union in 1986. Since this occurred along with an increase in the level of education within the labour force, the process is most likely demand driven. The results also indicate that modelling on average (i.e. OLS) misses important features of the wage structure. Quantile regression (QR) analysis reveals that the eOEect of education is not constant across the conditional wage distribution. They are higher for those at higher quantiles in the conditional wage distribution. Wage inequality expanded in Portugal over the 1980s and the returns to education had an important role in this process.