Simon Evan-Cook: When the maths does not add up

Rational logic is generally a good thing, but you can have too much of it. And we may have too much of it today - sometimes what seems logical from one perspective looks bonkers from another. Mathematics is the home of the rationalist. But, in the real world, mathematical logic can come a cropper and it is useful for investors to be able to spot such episodes when they arise. Rory Sutherland, in his book Alchemy: The Surprising Power of Ideas That Don't Make Sense, provides plenty of examples. One that stood out was his contention that 1x10 does not equal 10x1. He gives the example...