On 21 April 2021, the RSS Reading local group held a meeting titled: 'Harnessing the wisdom of a crowd of probabilistic forecasters with applications to predictions of Covid-19 mortality and macroeconomics'. The talk was given by James Taylor, professor of decision science at the Saïd Business School University of Oxford.
When probabilistic forecasts are available from multiple forecasters, aggregation can be performed to extract the wisdom of the crowd. Professor Taylor described aggregation methods that can be applied when there are many forecasters, or a record of past forecast accuracy is not available. The median and trimmed means have been proposed as simple and robust alternatives to the simple average. These methods, as well as a number of new proposals, were demonstrated with applications to macroeconomics and COVID-19 mortality.
There was an interesting reference to Surowiecki, James (2005) The Wisdom of Crowds: Why the Many Are Smarter Than the Few.