It’s spring and soon the fair weather protesters will take to the warming streets to denounce income inequality once again. The chants of the 99 percent, however, should fade in the face on an increasing body of economic research that reveals the hollowness of their fundamental premise. The rich have not gotten richer at the expense of the middle class. All income groups have seen economic growth. And there’s no evidence that the admittedly astonishing wealth of the 0.01 percent has had negative repercussions for the 99.99 percent.

James Pethokoukis,in The American Enterprise blog, cites a new academic study that takes an in-depth look at household income over time.

According to the Cornell study, median household income – properly measured – rose 36.7%, not 3.2% like Piketty and Saez [two frequently cited researchers] argue. That’s a big miss.

And all income levels got richer! Yes, the very rich did exceptionally well, mostly due to technology and globalization. Incomes rose 63% for the top 5%, 56% for the top 10% and 52.6% for the top 20%.  But everyone else made out pretty well, too. Incomes rose 40.4% for households between the 60th and 80th percentiles, 36.9% for the next quintile, 25.0% for the next, and 26.4% for the bottom 20%.

Here’s part of the problem:

See, Piketty and Saez made lots of odd choices about what to measure and how to measure it. They chose to measure something called “tax units” rather than households, a move which ignores the statistical impact —  including economies of scale — of couples who cohabitate, kids who move back in with their parents after college, and senior parents who live with their adult children.

They chose to ignore the value of all government transfers — including welfare, Social Security, and other government provided cash assistance — received by the household.

They chose to ignore the role of taxes and tax credits.

They chose to ignore the value of healthcare benefits.

Those things matter. Here’s another excellent report by Scott Winship at the Brookings Institution. It has cool and informative graphics, so please click through to RTWT. He acknowledges the super-rich, but adds this important insight:

… there is little compelling or consistent evidence showing that such extreme inequality-as against, say, European levels or the lower American levels of the 1960s-actually harms the middle class or poor. This is not to say that extreme inequality benefits Americans; it may, but it could simply be tangential to the lives of most people. Will Americans be better off in 2013 if Zuckerberg does not exercise any more stock options? Did the rest of us benefit from 2007 to 2009 when the share of income received by the rich fell? If not, how do we know that we were hurt when the share they received was rising?

Reihan Salam elaborates on Winship’s work:

To extend Scott’s thought experiment, would we be better off if the windfalls that flow from financial market exuberance in a global economy of savers accrued were diverted away from people residing in U.S. cities to people residing in Toronto or London or Singapore?

In case you missed it, Phil Gramm and Steve McMillin had a good op-ed on the topic in the Wall Street Journal recently.

While income distribution has become a source of protest and political debate, any analysis of taxes paid in high tax-and-spend countries shows that the U.S. has the most progressive income tax system in the world. An inconvenient truth for the advocates of higher taxes on America’s rich is that big governments in developed countries are funded not by taxing the rich more than the U.S. does, but by taxing everybody else more.

The protests won’t disappear soon. But some facts just may help shorten the debate.