"The results of a study by Michele Tribalat showed that the death rates of immigrants in France were surprisingly low: they were not only better than the national average, but far better than the rates specific to the socio-occupational categories the immigrants belonged to. Was this due to observation errors, to selection of the fittest applicants for immigration, or to the fact that immigrants adapted positively, that is, by taking the best (health services, living conditions...) and leaving the worst (overnutrition, road accidents...)? [The authors] investigate these questions here with respect to Moroccans living in France, first by a general analysis, then by a study of the causes of death. They confirm the surprisingly low mortality of Moroccan immigrants. But incidentally, in the case of mobility within France, adult mortality was shown to be roughly 11% lower among men who had changed regions at least once than among those who had not."