Ministers have been urged to remove foreign students from net migrationstatistics to allow the UK to continue to expand its share of the lucrative overseas student market.
And it said that the Office for National Statistics had made its migrationstatistics clearer, so that it was more easy for students to be identified in emigration flows "to give a more accurate measure of the contribution of students to overall net migration".
Some also think the statistics could reflect a migration of healthier women out of rural areas, leaving behind others who are too poor and unhealthy to relocate.
Kam Wing Chan of the University of Washington has compiled statistics which show that from 1990 to 2005 the most recent period for which reliable statistics are available there was an overall gross migration across provinces of about 80m migrants (see map).