A taster Oxford economics interview question

This is the kind of question asked in Oxford economics interviews. I have an extensive catalogue of past interview questions (90 pages), with particular expertise in the game-theory questions common in microeconomics interviews — I scored the best mark in the year at Oxford in game theory.

The game of 21. Two players. The first to say 21 wins. Each player can only go up by 1 or 2 from the previous player’s number.

Can you predict who will win? Can you explain the strategy for a forced win?

In a real interview, what matters is not whether you spot the answer instantly — it is how you reason out loud. WhatsApp me your answer and I’ll tell you whether an Oxford interviewer would be satisfied with it.

For how I prepare students for the whole admissions process — TSA, personal statements, college choice and interviews — see Economics Oxbridge Admissions.