What said the new economic geography about Portugal?

With this work we try to analyse the agglomeration process in Portugal, using the New Economic Geography models, in a linear and in a non linear way. In a non linear way, of referring, as summary conclusion, that with this work the existence of increasing returns to scale and low transport cost, in the Portuguese regions, was proven and, because this, the existence of agglomeration in Portugal. This work aims, also, to study the Portuguese regional agglomeration process, using the linear form of the New Economic Geography models. We pretend, yet, to explain the complementarily of clustering models, associated with the New Economic Geography, and polarization associated with the Keynesian tradition, describing the mechanisms by which these processes are based. As a summary conclusion, we can say which the agglomeration process shows some signs of concentration in Lisboa e Vale do Tejo (which is evidence of regional divergence in Portugal) and the productivity factor significantly improves the results that explain the regional clustering in Portugal (despite being ignored in the models of New Economic Geography). So, we can refer which the new economic geography said that in Portugal there is divergence between the continental regions.