There's no dearth of evidence showing that, for instance, parental wealth correlates with educational success of children. And then there's a loads of evidence showing that educational outcomes correlate with lifetime earnings.

Have you even tried looking for these citations? It's hard to believe you didn't find them because there is no shortage of published research on this topic. Here's the first link I picked off google scholar: http://www.jstor.org/stable/2673145

How about you provide citations for the case that you are making?