The last. The article wants to make it sound like this is inherited wealth (alla Picketty) but this isn't really supported. For example, you find much the same pattern even across say the cultural revolution, which I hear was rather rough on inherited nest eggs. The rec. book on this (as in one of the old comment threads below) is Clark, "The Son Also Rises" ( http://amzn.to/2jFnUmZ ).
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