A few weeks ago, some science and engineering students at London University lobbed me a question. “Lots of people on our course used to go to work for banks, but now that seems a really bad idea, so where do you think the job opportunities will be in the future for graduates like us?”

Where indeed? It is a question of great import right now – not just for current students but for policymakers across the western world. Until three years ago, smart, numerate students took it for granted that one of the fastest ways to become rich and successful was to dive into the world of complex finance, producing structures such as collateralised debt obligations (CDOs).