ETH Zurich

Wisdom of crowds refers to the phenomenon that the ag-gregate prediction or forecast of a group of individuals can be surprisingly more accurate than most individuals in the group, and sometimes – than any of the individuals comprising it. This article models the impact of social influence on the wisdom of crowds. We build a minimal-istic representation of individuals as Brownian particles coupled by means of social influence. We demonstrate that the model can reproduce results of a previous em-pirical study. This allows us to draw more fundamental conclusions about the role of social influence: In particu-lar, we show that the question of whether social influence has a positive or negative net effect on the wisdom of crowds is ill-defined. Instead, it is the starting config-uration of the population, in terms of its diversity and accuracy, that directly determines how beneficial social influence actually is. The article further examines the scenarios under which social influence promotes or im-pairs the wisdom of crowds