Where did all the migrants go? Migration data during the pandemic

What you need to know:

  • Current data shows that the migrant share of the UK’s population has declined due to emigration, particularly in London, but it is a smaller drop than the headline figures suggest.
  • Estimates of the migrant population are based on pre-pandemic projections of the total UK population that are likely to be too high.
  • These, plus other factors, create significant uncertainty meaning we should be cautious when comparing data from 2019 and 2020.

This commentary from the Migration Observatory at the University of Oxford, funded by Trust for London, examines what we know from currently available data about how the total size of the migrant population has changed in 2020, the year which brought the Covid-19 pandemic.

The effects of the Covid-19 pandemic are visible across the whole of society, and migration is no exception. From late March 2020, restrictions on travel, the closure of visa centres, and economic turmoil have had huge impacts on the immigration system. Following a large decline in international travel after the first UK lockdown, passenger numbers remained well below recent averages throughout the year. Grants of visas in categories across the immigration system also dropped in 2020.

One of the major questions facing migration researchers and policymakers currently is what this all means for migration patterns overall. How much lower is migration because of the pandemic? Who is still coming to the UK and who is not? Who is leaving? Is the migrant population declining?

Key findings

  • Headline data from the Labour Force Survey (LFS) suggest that the number of migrants living in the UK fell in 2020. In Q3 2020, the estimated foreign-born population was 8.3 million, down from 9.2 million in the same quarter a year earlier. This is a decline of 894,000 or 10%. However, there is enormous uncertainty about these estimates and compelling reasons to believe that they are not accurate.
  • Estimates of the migrant population are based on pre-pandemic projections of the total UK population that are likely to be too high. During the pandemic, the UK population may have declined, but this is not factored in to estimates of the migrant population. All else equal, this would mean that the official figures underestimated the decline in the foreign-born population. But all else is not equal.
  • When the pandemic hit, ONS switched to a socially distanced method of recruiting people into statistical surveys, and this appears to have disproportionately affected migrants’ participation. If migrants are less likely to participate than non-migrants with the new method of data collection, this means their numbers will be underestimated.
  • When we look at data on people recruited into the survey before the pandemic but surveyed in mid-2020, there is still a considerable decline in the migrant share of the UK’s population (e.g. due to emigration), particularly in London. But it is smaller than the headline figures suggest.
  • All this creates significant uncertainty and means that we should be cautious when comparing data from 2019 and 2020. Some of the changes we see will be real but some will be due to new biases in the data caused by the pandemic.