Between Guesstimates and Estimates? A Case Study of Unregistered and Irregular Populations in Belgium

Sylvie Gadeyne, Vrije Universiteit Brussel
Johan Surkyn, Vrije Universiteit Brussel
Pieter-Paul Verhaeghe, Vrije Universiteit Brussel
Janna Dinneweth, Vrije Universiteit Brussel

Migration is difficult to measure, model, and forecast due to the lack of standardized definitions. Key challenges include defining the spatial unit crossed and the length of time required to be classified as a migrant. While tracking regular migration is complex, irregular migration is even more elusive. Irregular migration has drawn significant societal attention. Terms like ‘irregular migrants,’ ‘unregistered citizens,’ or ‘illegal migrants’ are used to describe individuals without legal residency status, who may face expulsion if discovered. Accurate data on irregular migrants is scarce. The UN OHCHR and ILO estimated that by the late 2010s, migrants made up 3.5% of the global population, with 15-20% undocumented. In Europe, irregular migrant estimates for 2008 ranged from 1.9 to 3.8 million, though the EU-funded Clandestino project criticized these figures for being imprecise. To improve accuracy, we propose a new tool based on mortality extrapolation, using Belgian death certificates to estimate irregular migrant populations. For Belgium, the method estimates that there are about 490,000 ‘mobile’ foreigners around 2016, an estimated 329,000 were not in a regular status. The majority of these, around 217,000, were EU citizens, the remaining 112,000 were non-EU irregular migrants lacking diplomatic status, visas, or ongoing asylum procedures.

Keywords: Migrant Populations and Refugees, International Migration, Data and Methods

See extended abstract.

  Presented in Session 183. International Migration