Diversity

This chapter investigates the epistemic advantages of diversity, especially the effect of uncorrelated and negatively correlated votes. It also considers the influence of Hong and Page’s ‘diversity trumps ability’ theorem. One way to recognize the positive epistemic effect of diversity is to consider what happens if diversity is missing. Aggregating many voters who always vote in sync is pointless because no new, independent information is added by these ‘cloned’ voters. Consequently, if voters derive all their information from a small set of media channels or opinion leaders, the epistemic output deteriorates. Avoiding correlation is good, but even better outcomes can be achieved if votes are negatively correlated. We demonstrate the effect with a small example, but suggest that negative vote correlation is rare in realistic settings and difficult to ‘engineer’.