This report recommends that international students should be excluded from overall net migration figures, as moves to limit incoming student numbers for the sake of long-term migration figures put a valuable export market – higher education – at risk. A survey of the top 10 countries for international students suggests there is no international rule or standard preventing the UK from counting students in this way.

http://www.ippr.org/publication/55/8997/international-students-and-net-migration-in-the-uk