A Briton is “displaced” from the labour market for every four extra migrants from outside the EU that arrive in the UK, the Migration Advisory Committee (Mac) concluded.
The report is the first official examination of the impact of immigration and showed it has kept resident workers out of jobs.
Professor David Metcalf, chairman of the Mac, also criticised the use of GDP for measuring the effects of the influx of foreign nationals as “pro-immigration” because more migrants will logically expand the economy.
The findings are in contrast to a study by the National Institute of Economic and Social Research (Niesr) which claimed the number of immigrants coming to the UK had little or no impact on the number of unemployed.
However, the impact and displacement of British workers also does not last forever, the Mac report found.
“Those migrants who have been in the UK for over five years are not associated with displacement of British-born workers,” it said.
In the last five years the number of non-EU migrants of working age increased by 700,000 meaning some 160,000 Britons missed out on jobs, the report concluded.
Prof Metcalf said: “Assessing the impacts of migration is not a simple decision and our conclusions will require careful consideration by the Government.
“However, our research suggests that non-EEA migration is associated with some displacement of British workers.
“Financial impacts of migration are also complicated but considering overall GDP does not present a true picture.
“Instead, the impact of migration on the economic wellbeing of the resident population should be the focus.”
He went on: “Impact assessments must also consider wider effects such as the effects of skills transfer from migrants and their impacts on public finances, employability of UK workers, housing and transport.
“Although difficult to measure, these will ensure we can better understand the effects of migration.”
While he said it was difficult to identify the occupations which would be most affected, he highlighted jobs in information and communications technology, and in hospitality and retail—where a large number of foreign students are employed part-time—as sectors which could see the most impact.
Health and care services have also employed large numbers of migrants, he said, but this was mainly at a time of shortage of UK workers so British jobs were unlikely to have been displaced.
The Mac was asked to look at the impact of immigration from outside the EU and how that information was used in official impact assessments of the Government’s migration policies.
Prof Metcalf said the current system, which uses GDP to look at the impact on both UK residents and migrants, “can’t be the right way of thinking about this”.
It would be better to consider the impact on the economic wellbeing of the resident population alone, he said.
Any assessment of the economic and social impacts of immigration—and of specific immigration policies—critically depends on whose interests are taken into consideration, the Migration Observatory at the University of Oxford said.
Dr Scott Blinder, a senior researcher at the centre, said: “This report highlights the need to decide and articulate more clearly whose needs Government is prioritising when developing immigration policy.
“Trade-offs need to be confronted head on. Without more debate and clarity about whose interests policy is trying to maximise, we cannot hope to reach more agreement about the costs and benefits of specific policies.”
Immigration Minister Damian Green said: “This Government is working to reduce net migration from the hundreds of thousands a year we saw under the last government, to the tens of thousands we saw in the 1990s.
“Controlled immigration can bring benefits to the UK, but uncontrolled immigration can put pressure on public services, on infrastructure and on community relations.
“This report makes clear that it can also put pressure on the local labour market.
“We thank the Mac for its work and will now consider the report more fully as we work to regain control over our immigration system.”