This thesis explores the relationship between the determinants and the components of the labor outflow from Turkey, Italy and Spain to the industrial parts of Europe. It is a comparative study analysing the historical backgrounds of these countries and the characteristics of their people who work in various countries of the continent. It covers a period of fiftyfour years (1920-19Th) in three eras: The Ease Era, 1920-1950; The Pre-Migration Era, 1950-1960; The Migration Era, 1960-19Th. It studies the role of the Pre-Migration Era as a "thresho1" to the labor outflow with the hypothesis that the existence of the "threshold" plays an important role in making the components of the labor outflow the same for all the three countries considered, in spite of their different socio-economic backgrounds.For the pursuance of the objectives, the study uses secondary data on two sets of socio-economic variables. The first set analyses the Base Era and the Pre-Migration Era. The second set analyses the Migration Era,The results found prove the points hypothesized, but with variations.