Why is the UK such a brain magnet?

From what I have heard from students and academics in the UK there are a few key factors:

I think you may be undervaluing the effect of language. English is by far the most widely studied language and is the primary language of communication in academia. Students want to improve their English while they study. While universities in non-English speaking countries may teach in English and it is most likely possible to do research in English, day-to-day life can be isolating without knowing the local language, for example see here. It's also much less daunting to live in a country if you are already competent in the local language. Similarly for faculty, its much easier to work in a country where you're already fluent in the language rather than starting from scratch in a new language.

The UK is widely seen as welcoming and accepting of different nationalities and cultures. You could debate the extent that this is actually true, and it may be changing. It is certainly true at least of university cities such as Oxford and Cambridge as well as major cities such as London.

The UK is home to some of the best universities in the world in Oxford, Cambridge, Imperial College are all in the top 10 (the rest being in the US - which also suggests a language effect). These universities are also widely known worldwide. Oxbridge in particular offers a certain prestige which attracts many people, mainly due to its history.

I don't think the UK is necessarily attractive to top academics, especially in STEM subjects. The cost of living is high, especially in cities such as London, Oxford, Cambridge and academics (especially junior academics) struggle to live in these cities. There has been a large push by Oxford and Cambridge to provide subsidised housing for staff in order to attract/retain staff. I know many top academics who have left the UK for the US.

I also don't think the UK is particularly extraordinary in terms of research funding.

In conclusion, I believe language, culture, and brand recognition are the main factors for making the UK attractive to students and academics. Although this is threatened by the cost of living and rising xenophobia. The outlook for research funding is also uncertain due to Brexit.

In Commonwealth countries, many people believe that Cambridge and Oxford are the only elite universities.

Based on anecdotal experiences, and things I’ve heard from students I know who study in the UK, these are the reasons people choose to study/research in the UK:

1) Most UK universities don’t ask applicants to take unnecessary and expensive exams in order to apply. I mean, I’ve seen some English programs in the United States asking for GMAT and TOEFL scores. This I think is absolutely ridiculous.

2) Building on the my previous point, not a lot of UK universities ask for application fees. I’ve only heard of Oxbridge doing this. Depending on where you are in the world, these application fees can be up to a month’s salary, and most people aren’t willing to risk so much money on a gamble. I know universities do this as a barrier to entry for unserious applicants, but in the end they end up deterring high calibre applicants who simply can’t afford to apply.

3) This point is reletive, but in general, top UK universities are on the whole cheaper than top fee paying universities in other parts of the world. It’s still a lot of money but I think you would agree that the difference between $20,000 and $40,000 is significant.

4) Because of the fact that the UK colonised a huge portion of the world, there is a huge representation of common wealth citizens, making it culturally diverse. So foreigners tend to be able to slip right into society without drawing too much attention. Of course, this is not the case for every town and county in the UK, but it’s a reality.

5) Another thing that I will add is it’s reputation; the UK has done a good job or marketing it’s educational system. It’s purely good branding on the government’s part, as education is one of their largest exports

However, I think this is changing. Fewer and fewer international students are applying to UK universities because of the immigration laws that have been put in place. Students are basically kicked out of the country two weeks after graduation.