A Manifesto for Quantitative Multi-sited Approaches to International Migration

The article presents a manifesto for quantitative multi-sited approaches to international migration. When flows are registered, they are usually counted on the basis of the number of permits delivered to immigrants, which often excludes the re-entry of nationals who happened to live or lived abroad, as well as the departure of persons, nationals, and non-citizens alike, leaving the country. Censuses and national representative surveys routinely measure the stock of immigrants, but very rarely include questions that allow the study of expatriates or returnees. The fundamental justification for a multi-sited approach (MSA) of migration pertains to a basic epistemological principle: Any research on causal mechanisms, for example, the causes and consequences of migration, needs a counterfactual for reference and comparison. Analyzing the causes of departure in migration requires to comparing those who migrated with those who did not.