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Piketty's Capital in the Twenty-First Century
2013 (English edition 2014)· Idea or movement· Society: who gained, who lost
DebatedScholars disagree about what happened, what it means, or who said it.
French economist Thomas Piketty's 2013 bestseller argued, using two centuries of tax data, that capitalism tends to concentrate wealth.
See it on the Innovation & Wealth map →What happened
Building on tax records gathered with Emmanuel Saez, Anthony Atkinson and others for over 20 countries, Piketty argued that when the return on capital (r) exceeds economic growth (g), inherited wealth grows faster than wages and concentrates at the top. The mid-20th-century leveling, he said, came from wars, depression and high taxes, not a natural law. He proposed a global progressive tax on large fortunes. With its English edition (2014) it sold over 2.5 million copies, rare for a 700-page economics book.
Impact on society and the economy
It put wealth inequality at the center of economic debate and gave a generation of politicians and activists data and a formula, r > g.
How we know
The book's public data appendix and the World Inequality Database, plus extensive reviews and critiques by economists including Matthew Rognlie and Lawrence Summers.
Still debated
Critics dispute r > g as a law and his data; Rognlie found much of capital's rising share came from housing, not factories and other business capital.
Connections (4)
▸Marx, Engels and the critique of capitalism is echoed in the title of Piketty's Capital in the Twenty-First CenturyWell documented
The connection
Piketty's title deliberately nods to Marx's Capital (1867). Like Marx, he argues capitalism tends to concentrate wealth, but he rejects revolution and Marx's predicted collapse, relies heavily on two centuries of tax data, and proposes taxes rather than abolishing private property.
When and how
Marx wrote in London in 1867; Piketty in Paris in 2013. Piketty discusses Marx's 'principle of infinite accumulation' in his introduction.
How we know
The book discusses Marx directly. Piketty also told an interviewer in 2014 that he had never really managed to read Marx's Capital.
Debates
How Marxist the book is: some conservatives called it Marx updated, while many Marxists say it ignores labor exploitation, Marx's central idea.
▸Piketty's Capital in the Twenty-First Century framed the debate over The billionaire boom and the inequality debateMostly agreed
The connection
Piketty's r > g thesis and long data series gave critics of rising fortunes a vocabulary and evidence: wealth concentrates unless taxes, war or crisis intervene. His colleagues Emmanuel Saez and Gabriel Zucman designed Elizabeth Warren's and Bernie Sanders's 2019 wealth-tax plans and a 2% global minimum tax on billionaires discussed by the G20 in 2024.
When and how
Paris and Berkeley; the World Inequality Lab; Warren's 2019 plan of 2% a year above $50 million; Brazil's 2024 G20 presidency.
How sure are we?
The proposals cite their work directly; the book's influence shows in its sales, citations and policy debates.
Debates
Whether wealth taxes work: most European countries that had them repealed them, citing capital flight and low revenue; supporters say better design fixes that.
▸Piketty's Capital in the Twenty-First Century drew its data from records of Federal income tax (16th Amendment)Well documented
The connection
Because the 1913 income tax made the rich report their incomes, it created America's first systematic data on top earners. Thomas Piketty and Emmanuel Saez used these IRS tables to trace the top 1%'s share of income from 1913: high before 1929, much lower from the 1940s to the 1970s, and rising sharply after 1980.
When and how
Paris and Berkeley, 1998–2014; Piketty and Saez's 2003 paper on US income inequality since 1913, then Piketty's 2013 book, alongside Anthony Atkinson's work on Britain.
How we know
Their papers and the World Inequality Database document the method, explicitly built on IRS Statistics of Income tables.
Debates
Tax data miss untaxed income and shift with tax-law changes; economists Gerald Auten and David Splinter argue the rise in top shares is much smaller.
▸Postwar boom and the rise of the middle class is seen as a rare exception in Piketty's Capital in the Twenty-First CenturyMostly agreed
The connection
Piketty's data show that from 1914 to the 1970s, wealth and income in rich countries became unusually equal, because wars, depression, inflation and high taxes destroyed old fortunes while growth ran fast. He argues this was an exception: normally the return on capital exceeds economic growth (r > g), so inherited wealth concentrates, as it has again since about 1980.
When and how
Paris, 2013 (English 2014); Piketty and colleagues assembled tax records for France, the US, Britain and other countries reaching back to the 1800s.
How sure are we?
Tax-record series in the World Inequality Database show the mid-century dip and later rise in top shares, though how to measure them is debated.
Debates
Economists Gerald Auten and David Splinter argue US top income shares rose far less than Piketty and Saez estimate; whether r > g is a reliable rule is disputed.