While the employment effects of minimum wages are usually reported to be small (suggesting low substitutability between skill types), direct estimates suggest a much larger degree of substitutability. This paper argues that this paradox is largely due to a bias induced by the aggregation of...

I apply Ricardo’s principle of comparative advantage to a theory of factor substitutability in a model with a continuum of worker and job types. Highly skilled workers have a comparative advantage in complex jobs. The model satisfies the distance-dependent elasticity of substitution (DIDES)...

When types of workers are imperfect substitutes, the Mincerian rate of return to human capital is negatively related to the supply of human capital. We work out a simple model for the joint evolution of output and wage dispersion. We estimate this model using cross-country panel data on GDP and...

The Portuguese economy has been characterised by modernisation sincethe post-war period. Lisbon and the Tagus Valley is a centre of thisprocess. Hence, this region faces a high demand for highly skilledlabour. This paper analyses rates of return on human capital in theregion of Lisbon and in the...