Data, data everywhere and not a number to guide

Dangers of predictions

All through life our brains like to use 'general rules of thumb' when dealing with problems. These rules may come through personal experience or maybe they are more prescriptive and laid down by doctrine.

When dealing with problems I have sometimes found it useful to use a 'factor of three'. For example, if I plan to do a DIY job in the house, bitter experience tells me it will take three times as long as I might expect. Similarly, in my distant past, my military training followed the doctrine that when attacking a defended position, your force would need to be at least three times the size of similarly equipped defenders. Bank of England expands temporary intervention to index-linked gilts Such a guide can help avoid the shock of a gross under-estimation of outcome. The Bank of ...