Popolazione, migrazioni, sostituzione delle generazioni in Italia dal 1862 al 2020. Population, migrations, generation replacement in Italy from 1862 to 2020

The Italian population by sex and age in years from 1900 to 2020, is calculated in the absence of migration. The actual population relative to the same year is compared with the population reconstructed to highlight the impact of migration in its temporal dynamics and in the replacement of generations at birth and at later ages. The direct and indirect effects of migration, linked to the annual flows of entry and to changes in the annual number of births, are estimated. A new measure of the replacement of generations is proposed, based on the relationship between the amount at the same age of two generations spaced of thirty years.