There were always relatively large numbers of young adults among the emigrants. For example, in all years between 1840 and 1930, 65–75 per cent of American immigrants were aged 15–40 (Ferenczi and Willcox, (1929–31), II, 114). This is to be expected. Emigration involved an investment decision in which current income, which can be defined very widely, was forgone in the expectation of a higher income in the future. The younger the emigrant the greater the return over his or her lifetime. Emigration also tended to occur at particular stages of the life cycle, for example, when people married and/or left the parental home. This is one of the reasons why some historians have thought that the availability of land (the chance of obtaining a holding) was an important cause of emigration from agricultural areas. We have argued that it is unlikely to have been a sufficient cause.

There were, however, some important changes in the family status of the emigrants. In the earlier part of the nineteenth century the typical emigrants were a young family, often accompanied by children – although they may not necessarily have travelled together. There were roughly equal numbers of males and females. By the later nineteenth century the typical emigrants were young single adults and males outnumbered females by about two to one. For example, in 1866–70 (which were peak years) only a third of Norwegian emigrants were young men (15–30). By 1911–15, three-quarters of Norwegian emigrants were young men (Semmingsen, 1960, 53–4).