Piketty's research, which is immaculate, reaches back hundreds of years to establish a simple thesis: the American dream – and more broadly, the egalitarian promise of Western-style capitalism – does not, and maybe cannot, deliver on its promises. That, he writes, is because economic growth will always be smaller than the profits from any money that is invested. Economic growth is what we all benefit from, but profits from invested money accrue only to the rich.
The consequences of this are clear: those who have family fortunes are the winners, and everyone else doesn't have much of a shot of being wealthy unless they marry into or inherit money. It's Jane Austen all over again, and we've just fooled ourselves that the complicated financial system has changed a thing.
This is a deep point. Many American households, if they are lucky, will grow their wealth at the same rate as the economy. But, because the wealthy are growing their fortunes at a much faster rate, no one else can ever catch up.
http://www.theguardian.com/commentisfree/2014/apr/27/thomas-piketty-economist-american-dream