The Piketty-Saez data ignore changes in tax law and fail to count noncash compensation and Social Security benefits.
What the hockey-stick portrayal of global temperatures did in bringing a sense of crisis to the issue of global warming is now being replicated in the controversy over income inequality, thanks to a now-famous study by Thomas Piketty and Emmanuel Saez, professors of economics at the Paris School of Economics and the University of California, Berkeley, respectively. Whether the issue is climate change or income inequality, however, problems with the underlying data significantly distort the debate.
The chosen starting point for the most-quoted part of the Piketty-Saez study is 1979. In that year the inflation rate was 13.3%, interest rates were 15.5% and the poverty rate was rising, but economic misery was distributed more equally than in any year since. That misery led to the election of Ronald Reagan, whose economic policies helped usher in 25 years of lower interest rates, lower inflation and high economic growth. But Messrs. Piketty and Saez tell us it was also a period where the rich got richer, the poor got poorer and only a relatively small number of Americans benefited from the economic booms of the Reagan and Clinton years.
If that dark picture doesn’t sound like the country you lived in, that’s because it isn’t. The Piketty-Saez study looked only at pretax cash market income. It did not take into account taxes. It left out noncash compensation such as employer-provided health insurance and pension contributions. It left out Social Security payments, Medicare and Medicaid benefits, and more than 100 other means-tested government programs. Realized capital gains were included, but not the first $500,000 from the sale of one’s home, which is tax-exempt. IRAs and 401(k)s were counted only when the money is taken out in retirement. Finally, the Piketty-Saez data are based on individual tax returns, which ignore, for any given household, the presence of multiple earners.