The AP's Bernard Condon, Josh Boak and Chris Rugaber have a Q&A up today with Thomas Piketty, author of "Capital in the 21st Century."

Piketty's book is the most talked-about economics book of the year, arguing that capital is in the ascendance as labor has become diminishingly valuable since the 1970s, and that this can't stop, and won't stop.

He argues that the global economy -- and particularly the U.S. economy -- is headed back to the 19th century, when inherited wealth dominated the land and hard work was less important than one's parentage.

The whole AP interview is worth reading, but here's a bit of it:

Piketty's book earned the adoration of New York Times columnist Paul Krugman, who in a lengthy piece for the New York Review of Books praised the book's "sheer, exhilarating intellectual elegance" and said it "will change both the way we think about society and the way we do economics."

The work (which I have not yet read) puts the focus of economic discussion on capital (as the title implies), which Krugman says had been out of fashion in discussions of inequality. That's an important shift in the discourse:

Piketty argues that the rate of return on capital is higher than the growth rate of the economy, and likely will continue to be for some time.

We have recent evidence of high returns on capital. The average annual return on the S&P 500 over the past 10 years has been 6.5 percent, despite the recession, compared to 3.7 percent for U.S. GDP in nominal terms.

Tyler Cowen, in a dueling review of "Capital" for Foreign Affairs, argued that Piketty's definitions of capital and its rate of return is too hazy, and his outlook for the success of investment in capital too optimistic. He acknowledges that the book is "important," accesseible and will "revolutionize how people view the history of income inequality," but he poo-poos the idea of a global tax on wealth.

Anyway, seems like a book we should all try to read.