<p>Commitment to attend (ED) is valid for US universities only – let’s not freak out this brilliant person 
As for Oxford vs Yale, congratulations, obviously they are both great options!
A young man I know had a similar choice 4 years ago. He opted for Oxford, and is now a grad student at Yale
He thrived at Oxford, he was very very very happy there, and wouldn’t have missed that experience for anything. He’s having a great time as at Grad school at Yale as well.
Of course this is all anecdotal.
I think if you know what you want to study, and you’re sure, Oxford is the place for you.
It’s once in a lifetime experience.
Yale, as great as it is, boasts about being similar to Oxford, if you know what I mean. Even its buildings are an imitation of Oxford. Oxford is the original one (here I’m talking about setting only, not academics).
You get to live and study in an amazing place, full of history. Imagine living in a room from the 13th century! And the dining halls, my God! It’s really unique.
And the Oxford name beats every other name in the world, if you’re into brands
All this to say: go to Oxford!</p>