SCRATCH the surface of free-market capitalism and you discover something close to visceral fear. Recent events provide a good example: the US treasury’s extraordinary $800 billion rescue package was an enormous comfort blanket designed to restore confidence in the ailing financial markets. By forcing the taxpayer to pick up the “toxic debts” that plunged the system into crisis, it aims to protect our ability to go on behaving similarly in the future. This is a short-term and deeply regressive solution, but economic growth must be protected at all costs.

As economics commissioner on the UK’s Sustainable Development Commission, I …