The existence of these billionaires proves Thomas Piketty is wrong about wealth
... 70 percent of those who show up on Forbes’ 2014 list created their own wealth. Nearly three out of every four billionaires, then, are self-made entrepreneurs and innovators, far from being born with a silver spoon in their mouths.

What’s more, this figure is actually up from 1984, when fewer than half were self-made. If Piketty’s theory held any water, we would expect to see the same powerful families dominating the Forbes 400 decade after decade—the Rockefellers, the Carnegies, the Vanderbilts—with few new entrants....