In that last year, the positive evolution was due to a reduction in emigration figures (not confirmed by the Observatory data, which point to a stabilization) and an increase in immigration, especially by foreigners. In 2013 the reduction in the negative value of the migration net would have been due only to the increase in immigration as a result of a higher return of nationals (see table " Estimates of net migration of permanent movements, 2000-2014" in / Data / Global Estimates).
Link http://ec.europa.eu/eurostat/data/database
Cite as Pires, Rui Pena (2016), “Migration net less negative for the second consecutive year”, Observatório da Emigração. http://observatorioemigracao.pt/np4EN/5567.html