Gender Bias in Opinion Aggregation

Abstract

Gender biases have been documented in areas including hiring, promotion or performance evaluations. Many of these decisions are made by committees. We experimentally investigate whether committee deliberation contributes to gender biases. In our experiments participants perform a real effort task with subjective performance and rate the task performance of other participants. In a 3 $\times$ 2 design we vary the extent to which communication among raters is possible and whether or not the experiment is gender-blind. There is little evidence of gender bias in the absence of communication or with minimal communication. By contrast, gender bias is strong and highly statistically significant under open communication. In the latter case 60 percent of ratings received by men are revised upwards after deliberation compared to only 25 percent of ratings received by women. As a consequence women are ranked on average three positions lower after deliberation. We then test two interventions for open deliberation. Randomizing the order of speaking does not reduce gender bias, but an information intervention where raters are informed of gender bias in prior sessions does.