It is a sample survey included in the Inquérito ao Emprego (Employment Survey). Respondents are questioned about the existence of emigrant household members and, when applicable, about their intentions to remain abroad (to distinguish between permanent and temporary emigration).

The data collected, in addition to being used by the INE as an indicator of the annual number of emigrants, is integrated into Eurostat's European statistics on emigration.

Link for the methodological documents: http://smi.ine.pt/DocumentacaoMetodologica/Detalhes/1312
Link for the data collection method (questionnaire): http://smi.ine.pt/SuporteRecolha/Detalhes/10230