| You can get a reversal effect by self-selection. Let's assume a simplified model of reality that has exactly two biased filters - an "upstream" bias that causes the pool of qualified candidates to contain only (as an assumed example) 10% women, and a "downstream" bias that causes qualified women candidates to disproportionally not get chosen or get worse offers, that results in a majority of companies hiring only (again, assumed example) 5% women. If your company gets publicly known for hiring fairly, avoiding the second filter, then it may actually result in an effect that would "cancel out the effects of something high upstream" - simply because qualified women candidates may preferentially choose to apply at your organization, and your pool of candidates may contain significantly more qualified women developers than the national average, and thus also the people you hire would contain more qualified women developers than the national average. A company with a reputation "if you're of group X, you'll hate it here" can have a perfectly fair hiring process, but still won't get much of group X simply because they will avoid that organization. An organization like Ku klux klan doesn't really need to do racial discrimination when hiring as most black people simply won't apply. A fair hiring process would result in a proportion of women employees that generally matches the proportion of qualified women applicants, but the proportion of women among qualified applicants may vary significantly between different companies. |
Imagine that the female population of developers is 10%, that they exhibit in every way a performance distribution equal to males in job and interviewing performance, but that every company except yours is half as likely to hire a female candidate as the straight odds would suggest.
The candidate pool as experienced by all companies would consist of more than 10% females (as they would need to apply to twice as many places on average) and the average quality of the female candidate may well be higher than the average male candidate because of the adverse selection at play. (Qualified female candidates are being preferentially passed up in favor of inferior male candidates, leaving the residual female candidate pool more talent-rich than the male pool.)