What do we know about immigration?

by Christian Dustmann and Ian Preston

Centre for Research and Analysis of Migration (CReAM) at University College London.

In the current heightened political climate, consideration of the factors which determine immigration policy should be based on the best available evidence. We at the Centre for Research and Analysis of Migration have composed a briefing, intended to promote discussion that is informed and not alarmist, low key and not polemical. In that note we point out the challenges for researchers in measuring the social and economic consequences of immigration, backed up with detail and references to appropriate academic study in the respective field.

Restrictive immigration policies are a curtailment of individual freedom of movement that causes real harm both to individuals already in the receiving country and to potential immigrants. Families are prevented from being together, innovative and productive economic relationships are prevented from happening, fleeing persecution is made more difficult. To justify this requires strong reasons and reasons that are rooted in evidence rather than anecdote.

Advocates of tighter immigration control believe that reasons can be found in negative consequences for receiving countries.  For instance, wages may be depressed by inflows of labour; changes in the character of receiving neighbourhoods may cause cultural dislocation; pressure on public spending can worsen the state of public finances; pressure on public services may lead to deterioration in the quality of services to local populations.  All of these could, if true, be reasons for caution in immigration policy but it is not obvious that any of them are true. Immigration could be economically invigorating, promoting innovation and raising wages; local cultures could be enriched by the diversity that comes with immigration; taxes paid by young and productive immigrants could ease pressures on the public exchequer; staff born abroad could be essential to delivery of public services.

Whether or not any of these issues should be what determines immigration policy, it is surely true that discussion should be driven by something more substantial than hearsay and hunches. Measurement of the effects of immigration on receiving countries is challenging, fraught as it is within the need to separate genuinely causal from merely coincidental relationships and there is a great deal still to be understood. Nonetheless, we find the progress made by academic researchers in better understanding the phenomenon of immigration and in opening up new avenues of research to be encouraging. New scholars choosing migration studies as the topic of their academic career and new data sources paired with new methodology have provided new insights into phenomena that were previously not well understood. For instance, research is making progress in understanding the impact immigration has on innovation and entrepreneurship, on opportunities which immigration opens up for native-born individuals and in assessing the effects immigration has on the labour market and the economy of receiving countries, not just through employment and wage adjustments, but also through new trade opportunities and technological advances. In the briefing we try to summarise the best available research on some of the most critical impacts.

There are still many open questions that need addressing and the balance of evidence can always shift as research progresses, but there seems to us little basis in existing research to fear the consequences of or to feel the need to apologise for supporting a relatively open and progressive immigration policy.