>>512876427 (OP)
Per capita isn't a theory, it's simple logic. Let's say you have a cookie bakery with whites as 70% of the workforce and blacks as the remaining 30%. If every worker produces an equal amount of cookies, you would expect that whites make 70% of the cookies and blacks make 30%.
But what if Blacks made 60% of the cookies? Whites only make 40%. What can we conclude then? The obvious conclusion is that blacks produce more cookies, since their cookie production exceeds what you'd expect from their pop size. That's per capita.
This doesn't even get into WHY they make more cookies, just that they do. It also doesn't account for nonwhites being falsely recorded as white, or the complete lack of a hispanic breakdown.