Felix Salmon says that inherited wealth isn't what it used to be:
People might become stupendously wealthy, but we’re not really creating a new class of dynasts here. Instead, the money comes, and then, almost as fast as it came, it goes.
One reason is just that the idea of preserving wealth in one’s own family for many generations to come has rather gone out of fashion. If you inherit a fortune which has been in your family for hundreds of years, then you do generally feel a responsibility for maintaining it and passing it on to future generations. But families are smaller now than they used to be, and self-made billionaires don’t necessarily consider multi-generational wealth preservation as a particularly top priority. Indeed, it's more common to see billionaires swing the other way: Warren Buffett, for instance, likes to say that he wants to leave his children "enough money so that they would feel they could do anything, but not so much that they could do nothing".
The Dish 