New Delhi, Dec. 10 -- India's growth in gross domestic product (GDP), adjusted for inflation, for the period July to September slowed to a seven-quarter low of 5.4%. This caught many by surprise and left some shocked, especially market analysts and economists who make a living by forecasting and analysing such trends.

A Mint poll of 26 economists had predicted median growth of 6.5%. This deviation of the actual from the expected raises a few points.

First, the GDP growth rate was way off most forecasts. These projections typically tend to cluster and very few deviate significantly.

Those in the forecasting business seem to be believers in what economist John Maynard Keynes wrote in The General Theory of Employment, Interest and Money: ...