Despite their fine buildings and media visibility, business schools remain curiously insubstantial. Why do they exist and what do they do for us? Unlike medical or engineering schools, they lack an established body of practical knowledge, or a clear place in an executive’s career or in the university’s intellectual architecture.

Until recently simply asking this was heresy, especially as business schools have multiplied dramatically over the past 30 years.

Today there are signs of stagnation, especially in the US and Europe. The top schools fill their classrooms, but many two-year, full-time MBA programmes are struggling. Some schools have introduced part-time, weekend and online programmes. Others have shifted from “general management” to specialisms – finance, innovation management or entrepreneurship – or hired new deans to promote psychology, sociology or organisational behaviour. Others have responded with alliances to offer a multi-campus global experience.