Harvard University this year turned down more than 95% of those who applied.

But what is a “fair” system for deciding who should be rejected and who should be the lucky few to get a place?

What should the successful 5% look like?

Should it just be those with the highest academic credentials? Or would it be fairer to ensure a more diverse ethnic and social mix?

The admissions policy of the flagship US university is facing a legal challenge, which began this week in Boston, with accusations of racial bias against Asian-Americans.

And it’s a dispute that will be watched carefully by many other over-subscribed universities around the world.