The economist whose book we blogged on Thursday responds in the New York Times.

An excerpt.

Six days after The Financial Times launched an attack on the data behind Thomas Piketty’s much-debated tome on inequality, “Capital in the Twenty-First Century,” Mr. Piketty has offered his first detailed response to the newspaper’s criticism.

The short version: He doesn’t give an inch.

In response to a request from The New York Times to further address the criticisms, which The Financial Times published on Friday, Mr. Piketty, a professor at the Paris School of Economics, wrote that his data were correct, and his conclusions stood: Wealth inequality in Europe and the United States was high in the years before World War I, fell for much of the 20th century, and has been rising sharply again in the past three decades.

He argued that many of the things that The Financial Times identified as sloppy or arbitrary were in fact considered choices, which he explained in footnotes. Reasonable people might disagree with some of his choices of how to handle the data, he says. But even where there’s room for debate, any reasonable changes to his methodology would be small and not alter the broad conclusions, he suggested.

The part of the newspaper’s critique that throws the most doubt on his overall conclusions is its argument that wealth inequality in Britain has risen much less than Mr. Piketty contends. For that, he has sharp words. He says the newspaper’s analysis rests on apples-to-oranges comparisons of past data from tax returns mixed with current data from surveys, which makes the conclusions they reach deeply flawed, and contrary to what a wide range of other studies have found.

Retrieved May 29, 2014 from http://www.nytimes.com/2014/05/30/upshot/thomas-piketty-responds-to-criticism-of-his-data.html?hp