I'm not seeing where I claimed that California doesn't have many black people. I recognize it does, but as of 2010 57% of all black Americans live in the Southern US, and trends keep showing that number is only growing. Heck, black millenials in particular, the people who are of the age to contribute the most to the workforce in the next few decades are disproportionately moving to the south, from all regions[1].
To reiterate, my main point is still that it impossible to have a number of black people in tech that is even close to being representative of the overall population of black people in the US without including the southern US in the tech workforce.
Fair enough on busing though, seems there is a lot of inconclusive data floating around. First hand though, I went to an extremely diverse high school for 3 years (about equal parts white, black, and hispanic students) and a not diverse HS for one (90%+ white, in a different county) and there's no doubt that the on-campus environment was less toxic towards people of all races at the diverse one. I never once heard a white person throw out a racially insensitive term just to be "edgy" when half of that person's friends and classmates would actually notice and be offended. It happened way too often at the other school though.
[1]https://www.nytimes.com/2017/07/08/opinion/sunday/racism-is-...
> A report released last year by the New York City comptroller, Scott Stringer, found that between 2000 and 2014 about 61 percent of millennials moving to New York were white, while only 9 percent of 18- to 29-year olds moving into the city were black.
> Nationally, almost 82,000 black millennials migrated south in 2014, according to an analysis of census data done independently by Artem Gulish, a senior analyst at the Center on Education and the Workforce at Georgetown. Forty percent of these black transplants came from the Northeast, 37 percent from the Midwest and 23 percent from the West. Black millennials from abroad are more likely to settle in the South.