Fig. 3.

Average quantity of interracial exchanges initiated among the treatment group (white bars) and matched controls (black bars). The difference between bars represents the average treatment effect on the treated, where 95% confidence intervals quantify the precision of this effect as estimated by negative binomial regression (confidence intervals appear asymmetrically because they are converted from a logarithmic scale). Results are presented separately for (A) the overall effect (n = 30,495), (B) comparisons by account age and gender, and (C and D) comparisons by gender and racial background. The relatively low baseline rate of interracial contact among white site users is not itself surprising, given that whites constitute the majority of the study sample and therefore have the fewest opportunities for interracial exchange. Results in their original logged form are presented in Methodological Details.