Regulating the age structure of a population through migration

Since migrants are mainly adults, they may help to lower the mean age of the population in receiving countries. In practice, this effect has been moderated in European countries as well as in overseas receiving countries, because flows have not been regular [**]. But we can put the question the other way round, and ask what flows would be necessary to maintain a sufficiently young age structure in developed countries. Canada has considered implementing such a policy. Didier Blanchet [***] shows here this is unrealistic due to the cumulative migration cycles that such a policy would generate : we are, therefore, confronted by a perverse phenomenon which bears some resemblance to that put forward by Jean Bourgeois-Pichat and Si-Ahmed Taleb in a famous paper, published in Population, entitled “Un taux d’accroissement nul pour les pays en développement en l’an 2000. Rêve ou réalité ?” [****]