Bill Gates' Solution to Income Inequality The billionaire philanthropist wants to distinguish between the wealthy who are using their money for good and those who are merely consuming it.

It might not come as a surprise to many that Bill Gates, whom Forbes' magazine ranks as the second wealthiest man in the world, doesn't agree with the ideas of French economist Thomas Piketty.

It's Piketty, after all, who made a big splash this year with his book Capital in the 21st Century, which argued that it is a fundamental law of capitalism that wealth will grow more concentrated absent destabilizing events like global wars. Piketty's solution? A global tax on capital that could help governments better understand how wealth is distributed and stem the tide of inevitably increasing inequality, which Piketty believes is socially destabilizing.

If you believe the Forbes list, there is nobody in the world besides Carlos Slim who has more to lose than Bill Gates if Piketty's global wealth on tax were to be instituted. But Gates' critique of Piketty's work, published Monday on his personal blog, isn't completely self-interested. After all, Gates has already pledged to give away half his fortune over the course of his lifetime, a much larger amount than the 1% or 2% wealth tax, proposed by Piketty, would confiscate. His problem isn't with the idea that the super wealthy should spread their fortunes around, but ratherwith Piketty's mechanism and the incentives it would create:

"Imagine three types of wealthy people. One guy is putting his capital into building his business. Then there's a woman who's giving most of her wealth to charity. A third person is mostly consuming, spending a lot of money on things like a yacht and plane. While it's true that the wealth of all three people is contributing to inequality, I would argue that the first two are delivering more value to society than the third. I wish Piketty had made this distinction, because it has important policy implications."

Gates shares Piketty's goal of spreading wealth, yet he doesn't want to discourage the uber wealthy (like Gates) who are taking risks, investing in value-creating businesses, and helping the world through philanthropy. Gates' solution? Shift the American tax code from one that taxes labor to one that taxes consumption. Now, this sounds like standard, right-wing economic theory. Consumption taxes are usually favored by the wealthy and by conservative economists because they tend to be regressive in nature. Since everyone—rich and poor—have to consume some amount of goods and services, and because the proportion of income spent is much higher for the poor than the rich, consumption taxes like state and local sales tax burden the poor more than the rich.

But this doesn't necessarily have to be the case. Economists like Cornell University's Robert Frank have long advocated for progressive consumption taxes that could do much to solve what they perceive as the ills of growing income inequality. As Frank writes:

"Under such a tax, people would report not only their income but also their annual savings, as many already do under 401(k) plans and other retirement accounts. A family's annual consumption is simply the difference between its income and its annual savings. That amount, minus a standard deduction—say, $30,000 for a family of four—would be the family's taxable consumption. Rates would start low, like 10 percent. A family that earned $50,000 and saved $5,000 would thus have taxable consumption of $15,000.

Consider a family that spends $10 million a year and is deciding whether to add a $2 million wing to its mansion. If the top marginal tax rate on consumption were 100 percent, the project would cost $4 million. The additional tax payment would reduce the federal deficit by $2 million. Alternatively, the family could scale back, building only a $1 million addition. Then it would pay $1 million in additional tax and could deposit $2 million in savings. The federal deficit would fall by $1 million, and the additional savings would stimulate investment, promoting growth. Either way, the nation would come out ahead with no real sacrifice required of the wealthy family, because when all build larger houses, the result is merely to redefine what constitutes acceptable housing. With a consumption tax in place, most neighbors would also scale back the new wings on their mansions."

As you can see, one of the strategies behind this tax regime is to reduce the incentive to consume. With less conspicuous consumption, the poor would suffer from the negative effects of having less than those around them. As many behavioral studies have shown, relative wealth has more of an impact on personal happiness than absolute wealth.

Such a regime could appeal to both the right and left sides of the political spectrum. For those on the left, who are sometimes uncomfortable with the effects of a culture based around consumption, this tax would discourage such behavior. Meanwhile, a regime that encourages savings and investment would appeal to conservatives.

But for a progressive consumption tax to be truly progressive, there would need to be a hefty estate tax to prevent the rich from simply letting their wealth grow over generations through interest income. But Gates argues this is not a problem, because we have the ability to institute estate taxes, a policy which he is a "big believer" in.