The obstacles facing academic economists are formidable, for tenure and professional advancement still depend to a large extent on a willingness to comply with and to work within the tenets of orthodox theory.

The behavior of the economy as a whole, at the aggregate, macro-level, is built up from the individual equations at the micro-level.

At 2 per cent growth a year, an economy doubles in size in just thirty years.

The model of competitive equilibrium which has been discussed so far is set in a timeless environment. People and companies all operate in a world in which there is no future and hence no uncertainty.

Baseball players or cricketers do not need to be able to solve explicitly the non-linear differential equations which govern the flight of the ball. They just catch it.

Even in financial markets, the concept of market efficiency does not hold.

Despite the high salaries involved, employing economists is a cost-effective way for banks, and stockbrokers to secure exposure in the media.