Assessing the impact of migration on the employment outcomes of UK workers is a hugely challenging analytical issue. It is difficult to isolate the effects of migration from the other factors that simultaneously affect labour market outcomes. Even if one is confident that the effect of migration has been isolated, it is hard to be sure that what is measured is a causal estimate of the impact of migration on labour market outcomes, and not the reverse. Moreover, assessing aggregate national impacts may mask impacts that vary markedly across localities. Therefore, limitations in data and research methods, together with the likelihood that the effects of migration vary across time and place mean that studies differ in their conclusions. This increases the challenge of reaching a consensus view based on the evidence; there will generally be conflicting opinions.
Overall, it is concluded that there is relatively little evidence that migration has caused statistically significant displacement of UK natives from the labour market in periods when the economy has been strong. However, in line with some recent studies, there is evidence for some labour market displacement in recent years when the economy was in recession. Displacement effects are also more likely to be identified in periods when net migration volumes are high, rather than when volumes are low – so analyses that focus on data prior to the 2000s are less likely to find any impacts. In addition, where displacement effects are observed, these tend to be concentrated on low skilled natives.