The Great Income Divide
Thomas Piketty’s bestseller Capital in the Twenty-First Century is fueling heated debate about the relationship between capital accumulation and inequality. But the broader question is whether these debates will produce real solutions to two of the critical problems of our time: income inequality and limited social mobility.
WASHINGTON, DC – Thomas Piketty’s book Capital in the Twenty-First Century has captured the world’s attention, putting the relationship between capital accumulation and inequality at the center of economic debate. What makes Piketty’s argument so special is his insistence on a fundamental trend stemming from the very nature of capitalist growth. It is an argument much in the tradition of the great economists of the nineteenth and early twentieth centuries. In an age of tweets, his bestseller falls just short of a thousand pages.
The book’s release follows more than a decade of painstaking research by Piketty and others, including Oxford University’s Tony Atkinson. There were minor problems with the treatment of the massive data set, particularly the measurement of capital incomes in the United Kingdom. But the long-term trends identified – a rise in capital owners’ share of income and the concentration of “primary income” (before taxes and transfers) at the very top of the distribution in the United States and other major economies – remain unchallenged.
The law of diminishing returns leads one to expect the return on each additional unit of capital to decline. A key to Piketty’s results is that in recent decades the return to capital has diminished, if at all, proportionately much less than the rate at which capital has been growing, thereby leading to an increasing share of capital income.