Thanks! Your first observation is a very important one that hadn't occurred to me – I assumed that it was the undergraduate program that was being discussed. Are you sure that your interpretation is right (e.g. based on reading the original paper) or is it just a best guess?
Also Harvard's hegemony on this list is less of a reflection of its current position than its position decades ago, when the world's rich (who disproportionally are at the end of their careers) were educated.
Right, this makes sense
The fact that Penn in is second place is extremely suggestive that they are including business schools, although it could be the effect of the business school on the rest of the school (attitude, ability to get into finance, etc).
(I would disregard solipsist's quote because it not from the original source.)
[Added: Solipsist made good comments that partially account for the phenomenon, and Douglas_Knight pointed out that the figure of $200m+ below should be $30m+]
This article reports that Harvard has 2,964 alumni worth $200+ million, with a total wealth of $622 billion. These figures are staggering:
Note that Bill Gates "only" has ~$75 billion and that Mark Zuckerberg "only" has ~$30 billion, so that they don't account for Harvard's decisive advantage over other universities.
What is going on here? Why would Harvard come out ahead by such a large margin? Its acceptance rate is smaller than those of Stanford, Yale and Princeton, but by no more than 25%. Moreover, this has been true historically
One can ask a similar question of University of Pennsylvania, which is significantly less selective than Yale and Princeton, but has a decisive advantage over them.
Some possible explanations for the discrepancy:
Regardless of which of these explanations hold, there remains a question of why they would hold.
Is Harvard a better choice than other universities for students who aspire to be wealthy than other top schools?