Alchemy: The Surprising Power of Ideas That Don't Make Sense

by Rory Sutherland

For instance, in London I can put my two daughters into a car driven by a complete stranger and rely on them to be driven safely to their destination, because the stranger is driving a black cab. Before anyone can drive a black cab, he or she is forced to undergo a gruelling four-year initiation programme known as the Knowledge, for which they are required to memorise every street, major building and commercial premises within six and a half miles of Charing Cross Station, an area that includes 25,000 streets and 20,000 landmarks. This requires that they spend most of their spare evenings and weekends riding around on mopeds on test routes, before appearing in front of regular examination panels to test their knowledge of the quickest or shortest route between any two points; so gruelling is the process that it seems to enlarge the hippocampus of those who take part in it. In cabbie folklore, the model for the Knowledge was first suggested by Prince Albert.fn1 The test is certainly Teutonically stringent: over 70 per cent of the applicants either fail or drop out.fn2 As useful as it once was, many people feel the Knowledge has been made superfluous by the arrival of satnavs and Google Maps. Conventional economic thinking, obsessed with ‘market efficiency’, would argue that the Knowledge seems a ‘barrier to entry’ erected to maintain the scarcity of cab drivers. I was tempted to agree – but that was before I realised that the Knowledge had as much value as a signal than a n...