[bryondowd]

These studies almost always point to a very limited set of the "wealthiest" for their study. And if you think about it, it's obvious that the very top of the pyramid will mostly have people who were able to concentrate wealth somehow, rather than inheritors. Often, inheritance is split between more than one person. That alone would account for a lot of inherited wealth not meeting an arbitrarily "wealthiest" category. So naturally there's going to be a lot of churn at the top.