Sir

As a scientist working in a foreign laboratory, I can understand Colin Stoneking's frustration at the UK visa system for students (Nature 461, 1053; 2009). However, there is a reason for the unwieldy processes he complains about.

They have been developed to combat the problem of colleges advertising questionable courses to overseas students. In some cases, these are merely fronts to allow economic migrants to circumvent UK border controls, or to defraud overseas students of their tuition fees. A report by the UK Parliament's Home Affairs Committee found that of roughly 4,000 establishments catering to overseas students, 2,200 had not been licensed to sponsor students under the new immigration points system (see http://go.nature.com/9LXmvd). The implication was that some of them may be, to quote immigration minister Phil Woolas, “dodgy”.

The progress of science has always been, and will continue to be, aided by the free exchange of ideas and people between nations. But in the present economic and political climate, we should not expect to be treated as a special case.