European immigrants are more productive than workers born in the UK, the study from the Centre for Economics and Business Research (CEBR) and recruitment firm Harvey Nash also showed.
The study found leaving the EU or tightening our borders could lead to a £60 billion real-term cost to GDP over the next 35 years.
Charles Davis, head of macroeconomics at CEBR, said: "Non-UK EU-born workers earned £39 billion in total in 2012, bringing a wealth of skills and experience to the UK workforce and adding value to the economy."
Davis said the departure of such workers for the UK, or new measures to prevent EU migration, "could create skill shortages, hold back economic growth and worsen the position of the public finances".
Migrants more skilled
According to the study, migrant workers are more likely to be in work (63%) than UK-born citizens (56%) and more economically active - 69% of migrant workers are economically active compared to 63% of UK-born citizens.
Many migrants are more skilled than those born in the UK. They are more likely to be in managerial occupations and earn an average of 7.6% more than those born here.
Albert Ellis, CEO of Harvey Nash, said there is little evidence to suggest that EU immigrants are having a negative impact on wages or unemployment.
"Non-UK EU born workers are bringing much needed skills and value to the UK," said Ellis.
"Employment among those born in the EU 14 [countries] has increased by 21% in the last 10 years suggesting there is a demand for higher skilled workers that EU immigrants are meeting."
"We know that alongside tax considerations, the availability of talent is a major factor for businesses deciding where to locate."
Ellis added: "Our EU membership is important to attracting the right people and, in turn, for us to be globally competitive."
