Peter Ubel makes a case for behavioural economics and, in particular, for its place at the heart of public policy. He starts with a decent summary of the birth of free-market economics, and explains its roots in the idea that consumers in any market make rational choices.

The logical end point to this view is that government intervention to prevent problems such as obesity will fail, since in a free market consumers have made choices that have led to them being obese. Whether that's eating less healthily or taking less exercise, there is little point in trying to block such choices.

Behavioural economics takes the notion of rational decision-making to task and explains that decisions, both individual and collective, are far from rational. People can therefore be easily steered to encourage behaviour in the interests of the many (using government policy to persuade people to save for their retirement, for example).

Ubel's argument in favour of such "soft paternalism" is built in economic terms and his targets are those free-market libertarians who demand that free markets be left alone.

Harvard Business Press, £16.99