Wow, this is an extraordinary piece of work. Quite dense and long and lots of graphs but truly a groundbreaking bit of scholarship and well worth the effort. Painstakingly reviewing hundreds of years of various financial records, he destroys the cheerful Kuznets Curve, which underlies much of neoliberialism/globalization. Don't worry about inequalities (i.e. the rich get richer while the poor get poorer), they will diverge for a while then after a sufficient period of development they will converge again.

Piketty shows that this isn't the case and that even Kuznets didn't quite get why he thought his theory worked. The trends this was based on didn't account for the distortions of two world wars. Piketty then goes on to show that capitalism has no mechanism to encourage the convergences of inequalities and looking at current trends, the divergences will continue into the future at a ever increasing pace much to the determent of society.

I see why such places as the Wall Street Journal are reacting so shrilly to this work since the magical hand of the market, which has failed the world so miserably in the GFC and the market failure of climate change, will also fail in preventing growing inequalities. Policy interventions will be the only way to reign in these growing problems. Piketty has done a great thing in putting inequalities on the agenda in economics.