He's explicitly rejecting the notion that the already skewed nationwide tech population is relevant. One would think, that if I was a large company recruiting n

He's explicitly rejecting the notion that the already skewed nationwide tech population is relevant. One would think, that if I was a large company recruiting nationwide, with brand name that's a resume magnet, I would be drawing from the skewed nationwide tech population, because that's what's entering the pipeline. If controlling for geographic factors, that's not what's coming out, something looks amiss. He explicitly is saying that "talent" is determining factor. That seems odd, since that would be conditionally independent.