Amartya Sen, as befits a Nobel laureate, has often produced careful calculations to throw light on dark situations, such as the number of deaths caused by Mao's Great Leap Forward in China.

So, it was astonishing to hear him say on a recent TV programme that the delay in passing the Food Security Bill was causing 1,000 deaths per week (equal to 52,000 per year). This was not based on any known methodology — he simply plucked the figure out of the air and threw it at the audience. Read More