Graduates of top universities earn more in the future, but how much of that is down to the teaching? After all, the best universities are more likely to receive applications from people who are already bright. One study got around this by analysing students who got into top US colleges, like Stanford and Yale, but decided not to go. Interestingly these students didn’t seem to suffer by attending less-selective schools. Apparently, an acceptance letter from Stanford is just as good as going.