Cooperation and coordination among siblings: Brothers' migration in France, 1870-1940

Recent works emphasize the role of the family in migration decisions. They particularly insist on the specific schedule of mobility that depends not only on an individual life cycle but also on the situation of the whole family at a given time. French military registers provide us with very detailed longitudinal information on migrations, scarcely available in other sources. We consider the smallest family group, male siblings, and focus on their migration behaviours. We start by testing the simplest family indicator, birth rank, and we show that, by itself, it has no effect on migration decisions. We then study whether or not there is competition among siblings and, in particular, if the migration of one of them encourages or prevents mobility of the others. Comparing the chances for an individual to move before and after the migration of his brother, we show that brother mobility did have a positive influence on someone's own mobility. However, we find little evidence of the use of networks when looking at migrants' place of destination. Sons are more prone to move in a given family than in another but they don't go to the same places. Therefore, we argue that mobility appears as a collective decision that depends on family strategies. This approach sheds new light on the migration process while insisting on its family component.