Statistics on UK students studying or working abroad are not straightforward as different institutions and agencies define 'mobility' in different ways.
The International Unit website Go International has an extensive range of up to date reports including UUKi research on a wide range of issues relating to student mobility.
Using data from Erasmus and data collected from 135 UK institutions, Joan Anton Carbonell produces an annual survey of outward mobility from the UK (The latest report in Nov 2014 runs from 2007-8 to 2012-13). These figures show the latest total of 20,064 UK students spending time abroad for a period over three months and includes students outside the Erasmus countries.
and Experiences of UK Students Studying Abroad by Professor A
M Findlay (University of Dundee) and Professor R King (University
of Sussex) et al. BIS Research Paper No.8 (January 2010). This report analyses statistics on mobility and presents findings from a survey of the application intentions of 1400 final year students in England and a survey of UK students studying in six countries outside the UK.
Statistics on UK students studying abroad under the Erasmus programme
are available from the British
Council's Erasmus unit.
Further information on research in this area is included in King, Findlay & Ahrens (2010) International student mobility literature review:
Report to HEFCE, co-funded by the British Council, UK National Agency for Erasmus