1. NIPE and School of Economics and Management, University of Minho, Braga, Portugal
2. UNIAG and Polytechnic Institute of Cávado and Ave, Barcelos, Portugal
3. Lab2PT and Institute of Social Sciences, University of Minho, Guimarães, Portugal
4. SREA-Regional Statistic Service of Azores, Instituto Nacional de Estatistica, Angra do Heroísmo, Portugal