Some economists are better performers than others. Indeed, the top forecaster was around 5 per cent more accurate than an average forecaster. But then Soll added a twist. Instead of looking at individual predictions, he took the average prediction of the top six economists. To stretch language a little, these forecasters were being placed into a team. The average of their predictions is what you might call their collective judgement. Soll then checked if this prediction was more accurate than the top-ranked economist. Now, in a simple task, the answer must be ‘no’. In a running race, the average time of six runners has to be slower than the time of the fastest runner. This is what Justice Scalia had in mind when he argued for a trade-off between diversity and excellence. But this analysis flips when we move from simple to complex problems. Indeed, when Soll compared the collective judgement of six economists with the judgement of the top economist, it was not less accurate, it was more accurate. And not just a little more accurate but 15 per cent more accurate . This is a staggering difference - so large, in fact, that it shocked the researchers.
