Three of our predictable irrationalities give the swine flu story much more impact than it should have — and in this case, it would be better if we were more rational.

Fixing some of the glaring irrationalities in the tax system would have as big an impact on medium-term growth prospects as anything else Mr Osborne is likely to announce in his budget.

The irrationalities of the Chinese financial system mean that in key sectors like steel China builds too many factories, and props up too many moribund companies, causing massive overcapacity.