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Policies to tackle UK irregular migration are based on a data black hole.

11 Sep 2020

UK policies to tackle irregular migration are based on a fundamental lack of data on the irregular migrant population in the country, new analysis from the Migration Observatory at the University of Oxford highlighted today.

The Observatory has published two new pieces of analysis today (Friday September 11th) dealing with what is – and what is not – known about the UK’s irregular migrant population.

The first piece, a new briefing on Irregular Migration in the UK – highlights that the UK government has not since 2005 published estimates of the size of the UK’s irregular migrant population. Neither does the government publish statistics on the number of people whose migration status is regularised under long residence routes.

One result of the irregular migration data black hole – explained in the Observatory’s second new publication, Recent estimates of the UK’s irregular migrant population, has been a number of unofficial estimates of the UK’s migrant population. Recent examples include estimates from the Pew Research Center and the Greater London Authority. However, analysis by the Migration Observatory shows that the methods currently used to develop any estimates are unreliable.

Dr Peter William Walsh, an author of both new publications, said: “Several estimates for the UK’s irregular migrant population have been bandied around over the last year, but we cannot rely on any of them as robust estimates. There is little doubt that the UK does have a number of residents without legal status, or whose status is unclear for one reason or another, but at this stage quantifying it with any degree of reliability has proved impossible for those who have tried.”

Dr Walsh added: “The lack of a clear baseline number for the irregular migrant population in the UK means that policies such as the ‘Hostile Environment’ that are designed to reduce the number of irregular migrants in the country cannot be evaluated, so – whatever you might think of them in principle – you can’t know if they work.”


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