The best analysis yet of Hillary Clinton’s tax proposals

Hillary Clinton’s tax plan would raise $1.1 trillion over the next decade, with nearly 80 percent coming from the top 1 percent of Americans, a new analysis by the Tax Policy Center shows.

So far this cycle, the Tax Policy Center — the leading nonpartisan think tank for tax and revenue issues — has released analyses of the tax plans of Donald Trump, Ted Cruz, Marco Rubio, and Jeb Bush, who is no longer in the race. This week, TPC started to crunch the numbers on Democratic plans.

First up is Hillary Clinton. Unlike the GOP candidates, Clinton hasn't released a "tax plan" as such. Instead she's endorsed a series of proposals, most of them aiming to increase taxes on the wealthy. The big ones are:

• A cap on itemized deductions for the wealthy. People in the 33 percent tax bracket and higher (single with more than $190,150 in taxable income, and couples with more than $231,450) would have the value of deductions capped at 28 percent. This is borrowed from one of President Obama's budget proposals.
• An increase in the estate and gift tax rate to 45 percent from 40, and a decrease in the exemption to $3.5 million from $5.45 million. This basically restores the tax to its 2009 level, but leaves it much lower than it was under Clinton's husband.
• A 4 percent surtax on income above $5 million. The cutoff wouldn't be indexed for inflation, so it would gradually affect more and more people.
• Increased capital gains taxes on investments held for shorter periods. Currently, gains on investments sold after less than a year are taxed at normal rates, and all other gains are taxed at a lower special rate. Clinton would apply the normal rate to investments sold after less than two years and then apply a sliding scale of rates until an investment is held for six years or more, at which point it would be a full discount:

• Imposing a minimum 30 percent effective tax rate on all taxpayers making more than $1 million (a.k.a. the "Buffett rule," also an Obama proposal).
• A variety of proposals to deter tax avoidance by multinational corporations.

Clinton's campaign told TPC she plans to propose, "a package of additional tax cuts targeted at low- and middle-income families later in the campaign." But due to lack of specifics, TPC could not include those cuts in its analysis.

TPC finds that Clinton's tax proposals would raise $1.1 trillion over a decade. When you take into account lower interest costs, they'd reduce the deficit by $1.25 trillion. Besides the obviously difference that Clinton is calling for an increase in taxes rather than cuts, the scale of her plans is much smaller than those of her Republican rivals. Trump, for instance is proposing a $9.5 trillion tax cut, which would rise in price to $11.2 trillion when you take interest into account.

The biggest revenue raiser of the bunch, TPC finds, is the itemized deduction cap that Clinton borrowed from the Obama administration, followed by the 4 percent surtax, the capital gains hikes, and the Buffett rule:

Clinton has assiduously avoided proposing any broad-based tax increases, most notably declining to endorse the FAMILY Act, a proposal by Sen. Kirsten Gillibrand (D-NY) with widespread support within the Democratic Party (including from Bernie Sanders) that would finance 12 weeks of paid family and medical leave with a small 0.2 percent payroll tax on both employers and employees.

As a result, her tax increase proposals overwhelmingly hit the top 1 percent, which would bear 77.8 percent of the tax change; the top 0.1 percent would pay for more than half of it. But TPC does find that some people in the 99 percent would pay more:

The biggest hikes in both percentage terms and absolute dollars go to the top 0.1 percent:

What Clinton's plan tells us about taxing the rich

The one overriding constraint Clinton is operating under is a commitment not to raise taxes in a way that spills over from the rich to the upper middle class. And that's a lot easier said than done.

The NYU tax expert David Kamin has a great paper, "How to Tax the Rich," explaining some of the difficulties here. A big one is that the richest of the rich tend to make a large fraction of their income from investments: capital gains, dividends, interest, etc. And the US tax code provides a substantial break for investment income. The top income tax rate is 39.6 percent for wages but only 20 percent for capital gains; Obamacare added a 3.8 percent investment income surtax, but that mostly just offsets the 3.8 percent the rich pay in Medicare payroll taxes.

One natural way to tax the rich, then, would be to increase taxes on investments. But it's not that simple, as Kamin notes. You can raise them on dividends, sure, but if the tax rates on capital gains get too high, then people will stop selling their investments as much, and revenue will actually fall. The problem isn't that the high taxes hurt economic growth, mind you. The problem is that people just hold on to their stocks for longer.

The revenue-maximizing rate for capital gains is more like 28 to 32 percent, according to the Joint Committee on Taxation and the Treasury Department — not too much higher than the combined 23.8 percent top rate. Kamin estimates that you could get, at most, $10 billion to $15 billion a year from raising capital gains rates to their revenue-maximizing rates, and another $10 billion from treating dividends like regular income. That's not chump change, but in terms of the federal budget it's not a whole lot either. Clinton's capital gains tax increase raises even less: about $8 billion a year on average for its first decade.

The Buffett rule is another way to try to raise taxes on investments, by imposing a 30 percent minimum tax rate on millionaires that applies regardless of where the money comes from. But as Kamin notes, this would also discourage people from selling investments, limiting how much money you can raise from it. Clinton's version raises less than $12 billion a year in its first decade, TPC finds.

More promising options, Kamin concludes, are raising estate taxes, raising individual income tax rates, and limiting deductions for the rich. Clinton's plan does all of these, and it's where she gets most of her increased revenue. The deduction cap is by far the biggest revenue raiser, followed by the estate tax increase, then the 4 percent income tax surcharge on the superrich.

Clinton could go still further here. She could try a more aggressive deduction cap, like a $17,000 limit or a 2 percent of income limit; those would raise even more money, even if you phase them in only for the wealthy. She could start raising income tax rates at $200,000 rather than $5 million, and raise them even more. She could increase the top estate tax rate to 55 percent, not 45 percent, and decrease the exemption to $1 million, putting the tax closer to where it was under Bill Clinton. But she's targeting the right places for soaking the rich.

How to tax the rich even more

The biggest tax hike for the rich that Kamin champions that Clinton hasn't touched is "realization on bequest or gift." This sounds ridiculously dry, but it basically means applying capital gains tax on all property that's bequeathed or given to someone.

Here's an example. Imagine you're living in New York in the 1980s and buy an original Basquiat painting for $200. By the time you die and leave that painting to your daughter, it's worth $40 million. If your daughter then sells it, she'll pay capital gains tax — but only on the difference between the sale price and $40 million. The tax code defines heirs' gain relative to the value of an asset when they inherit it, rather than its value when their bequeathers bought it. This is known as "step-up basis," and TPC head Len Burman has called it "arguably the biggest loophole in the tax code for high-wealth households."

The Obama administration and many others have proposed replacing this with realization upon bequest or gift. That would mean that your hypothetical daughter would pay tax on your nearly $40 million gain as soon as you died, not whenever she felt like selling the painting.

That would raise at least $40 billion a year, Kamin estimates, in part because people currently hoarding assets until death, when the gains become tax-free, would now have a reason to sell them off early. That's good for overall economic efficiency as well. If Clinton wants to raise even more revenue, this would be a good proposal to tack on.