Well, there's this data: http://som.yale.edu/news/2017/04/in-new-york-times-prof-jaso...
but it doesn't seem to be reaching the right ears. The thing is that a staggering lack of every kind of diversity persists within the tech sector. It is a much bigger problem than the occasional "wrong hire". There will always be some error... some bad hire that slips through any process as we perfect our hiring systems. The data from this study and the positive and highly effective blind orchstral auditions clearly show that we can still improve our strategies in finding the most skilled professional for the job. Perhaps we also need to work on expanding our notions of culture on the job and working toward becoming better engineers who can work with all types of people who want to produce great work. Perhaps you aren't aware of the closeness with wich orchestral musicians must work with stand partners, section members and the whole team and just how detrimental it can be for one person to have a problem so small as "plays great but moves around too much when playing" or "plays great but is an arrogant jerk during rehearsal creating bad morale"... and the thing is, we know there is probation review. It is an integral part of the hiring process. It isn't considered an error. We accept it as a phase. So why must software teams at companies with lots more wealth than a symphony orchestra expect to get it exactly right with a few wonky culture fit interviews and a relatively small whiteboarding section with the occasional take home project? They can and should find the funds to get serious about diversity in their industry. And frankly, with at-will contracts being the norm, every candidate is always "on probation".