•

Over the last few decades we've become a market society where almost everything is up for sale – there are cash incentives for doctors who diagnose dementia patients and for teachers whose students get better exam results. The problem, says Harvard philosopher Michael Sandel, is that where money determines access to necessities such as health and education, inequality matters more than it otherwise would What Money Can't Buy by Michael Sandel, published by Penguin, £7.99 from the Guardian Bookshop