The economy would lose some of the "best and brightest graduates" if Britain left the EU, according to new research.
Students from the EU are more likely to achieve first class degrees and earn a high salary, a report by the Institute for Social and Economic Research found.
Study author Dr Renee Luthra told The Observer that a vote to leave "would almost certainly reduce the flow of these high-performing students".
Dr Luthra and her colleague Greta Morando used data from the Destination of Leavers from Higher Education survey and found that undergraduates from the EU were 50% more likely to obtain a first class degree than their British classmates.
They are also more than twice as likely to continue with postgraduate study.
Although EU students make up only 5% of undergraduates in the UK, one in eight research students are from the EU.
Of those, two thirds are in science, technology, engineering and maths (STEM) which Dr Luthra described as "of vital importance to the UK economy".
She said: "The EU students at UK universities are clearly the best and the brightest in their class - on the whole their achievements outstrip their British classmates and they represent a significantly well-qualified group of graduate workers entering the UK workforce.
"This is especially true of undergraduates, as those EU students who study and remain in the UK to work are very high-performing. These undergraduates will be having a very positive impact on UK industry."
She added: "The uncertainty surrounding a vote to leave the EU would almost certainly reduce the flow of these high-performing students, particularly in the short-term transition period."