An Empirical Analysis An Empirical Analysis An Empirical Analysis An Empirical Analysis An Empirical Analysis An Empirical Analysis An Empirical Analysis An Empirical Analysis about Motivations about Motivations about Motivations about Motivations about Motivations about Motivations about Motivations about Motivations among Hospital among Hospital among Hospital among Hospital among Hospital among Hospital among Hospital among Hospital FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS Research Research Research Research Work in Work in Work in Work in Progress Progress Progress Progress FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS FEP WORKING PAPERS n. n. n. n. 418 418 418 418 June June June June 2011 2011 2011 2011 Volunteers Volunteers Volunteers Volunteers Volunteers Volunteers Volunteers Volunteers Marisa R. Ferreira Marisa R. Ferreira Marisa R. Ferreira Marisa R. Ferreira 1 2 1 2 1 2 1 2 Teresa Proença Teresa Proença Teresa Proença Teresa Proença 1 3 1 3 1 3 1 3 João F. João F. João F. João F. Proença Proença Proença Proença 1 1 1 1 1 Faculdade de Economia, Universidade do Porto, Faculdade de Economia, Universidade do Porto, Faculdade de Economia, Universidade do Porto, Faculdade de Economia, Universidade do Porto, 2 ESTGF ESTGF ESTGF ESTGF-IPP; IPP; IPP; IPP; CIICSESI CIICSESI CIICSESI CIICSESI 3 CEGE CEGE CEGE CEGE - UCP UCP UCP UCP