MIrreM Press Release: New Database and Report Assess Key Estimates of Irregular Migrants

Migration researchers from the world’s leading universities and research organisations have released a new public database which brings together and assesses the latest estimates of how many migrants with irregular migration status live in various European countries and North America.The MIrreM project, a collaboration between 18 institutions, including the University of Oxford, which led on this aspect of the work, officially launched a new database of irregular migrant population estimates, the MIrreM Public Database on Irregular Migration Stock Estimates (‘the Database’). A new MIrreM Working Paper The Irregular Migrant Population of Europe presents an analysis of the Database. Measuring populations of irregular migrants can be complicated as fears and risks around immigration enforcement prevent many members of these communities from sharing personal information in surveys, censuses and other data gathering processes that typically allow statisticians to calculate population sizes and composition. As such, all data covering this subject is inherently uncertain and comes with large margins of error. However, the Database substantially updates previous assessments of the irregular migrant population in Europe, such as the estimates by the Clandestino research project dating back to 2008 and a subsequent study by the Pew Research Centre from 2019. MIrreM thereby offers essential new estimates, after a prolonged period of transformations in the European migration landscape. The Database also incorporates estimates of the United States’ irregular migrant population. For more information on the potential and pitfalls of using irregular migration data, including key takeaways for policymakers, see the MIrreM Policy Brief How fit is the available data on irregular migration for policymaking?