Trump’s Plans Could Increase U.S. Debt While Raising Costs for Most Americans

A new analysis finds that Vice President Kamala Harris and former President Donald J. Trump’s plans would both add to the deficit, but Mr. Trump’s proposals could create a fiscal hole twice as big.

Former President Donald J. Trump’s economic proposals could inflame the nation’s debt burden while ultimately raising costs for a vast majority of Americans, according to a pair of new economic analyses that are among the most in-depth studies to date of the Republican nominee’s plans.

The Committee for a Responsible Federal Budget, a nonpartisan group that seeks lower deficits, found that Mr. Trump’s various plans could add as much as $15 trillion to the nation’s debt over a decade. That is nearly twice as much as the economic plans being proposed by Vice President Kamala Harris.

And an analysis from the Institute on Taxation and Economic Policy, a liberal think tank, found that Mr. Trump’s tax and tariff plans would, on average, amount to a tax increase for every income group except the top 5 percent of highest-earning Americans.

The two new studies differ in some respects. The budget group looked at the cost of both candidates’ tax and spending plans over 10 years, while the tax institute focused on what the impacts of Mr. Trump’s tax and tariff plans would be in 2026. But together they show that Mr. Trump’s agenda could be both costly and regressive by placing a greater burden on those making the least amount of money.

Over the course of his campaign, Mr. Trump has floated a flurry of potentially far-reaching policies, including exempting certain forms of pay from taxes and levying broad tariffs on nearly all imports to the United States. He also wants to extend elements of the tax law he enacted in 2017 that are set to expire after next year.

“It’s almost difficult to come up with a tax plan that would raise taxes on most Americans, but still increase the deficit by hundreds of billions of dollars a year — and that’s what this does,” Steve Wamhoff, the federal policy director at I.T.E.P., said.

The C.R.F.B. cautioned that its estimates remain subject to considerable uncertainty as many of the proposals that Mr. Trump and Ms. Harris have been pitching are thin on details. It presented three cost scenarios for each campaign’s nascent economic agenda.

On the high end, Mr. Trump’s plans would cost $15 trillion over 10 years, while Ms. Harris’s would cost $8 trillion. In a midrange scenario, the former president’s second-term agenda would cost $7.5 trillion and Ms. Harris’s plans would cost $3.5 trillion. And at the low end, Mr. Trump’s plan would add $1.45 trillion to the debt by 2035 while Ms. Harris’s would add nothing, making it “deficit neutral.”

“Both the Republican and Democratic candidates for president have put forward campaign plans that would, at best, maintain the status quo and, at worst, add tremendously to our debt and deficits,” the C.R.F.B. report said. “Even in the best-case scenario, neither candidate’s plan would be sufficient to put debt on a downward path and point America toward a more secure and sustainable fiscal future.”

The Harris campaign noted that she has said publicly that her policies would be paid for and that the Biden-Harris administration has proposed budgets that would reduce the deficit by $3 trillion.

The Trump campaign suggested that the Committee for a Responsible Federal Budget was misjudging the effect that the former president’s proposals would have on the economy.

“President Trump’s plan will rein in wasteful spending, defeat inflation, reduce the burden of interest costs and ignite economic growth that fuels federal revenue so we can make our economy great again,” said Brian Hughes, a senior adviser to the Trump campaign.

A persistent difficulty for budget forecasters in Washington has been estimating the impact of Mr. Trump’s plans to exempt overtime pay and tips from taxation. Many experts have cautioned that the proposals would encourage more people to classify their earnings as tips or overtime. Whether that happens could vastly change the cost of the plans — and potentially reward high-income Americans with the resources to exploit the tax breaks.

The team of researchers from the Institute on Taxation and Economic Policy assumed that Americans would not significantly change their behavior because of those exemptions, noting the uncertainty around that factor. They analyzed all of Mr. Trump’s tax proposals — extending his 2017 tax cuts, restoring the full state and local tax deduction, cutting corporate taxes and exempting tips, overtime and Social Security benefits from taxes. They found that those plans would cut taxes across the income spectrum, with the highest-income Americans benefiting the most.

But the savings many Americans would see under those cuts are more than offset by Mr. Trump’s plans to impose widespread tariffs on imports, according to the think tank’s estimates. Mr. Trump has thrown out several different ideas for raising tariffs, and the researchers base their analysis on a 20 percent tariff on all imports and a 60 percent tariff on goods from China. Another tax increase included in their estimate is repealing the green-energy tax credits passed under President Biden.

Overall, Mr. Trump’s plans would provide a tax cut worth, on average, 1.2 percent of overall income for the richest 1 percent of Americans, while the rest of the top 5 percent would see a 1.3 percent boost. Every other income group would lose money because of the higher costs created by the tariffs, with the bottom 20 percent experiencing a loss worth 4.8 percent of their income on average.

That’s the equivalent of the richest 1 percent paying $36,320 less in taxes, while the bottom 20 percent pay $790 more, I.T.E.P. estimated. The middle 20 percent of Americans would pay $1,530 more, on average, equivalent to 2.1 percent of their income.

Because tariffs increase the cost of goods, they fall disproportionately on poorer Americans who spend much of their money on groceries, clothing and other consumer items. Rich Americans would also pay more because of the tariffs, but the extra costs amount to a far smaller share of their overall income. Low-income Americans pay less in taxes, meaning tax cuts do not benefit them as much as they do high earners.

Mr. Trump and his campaign have argued that his tariffs will only affect companies operating abroad, but economic studies have repeatedly found that the costs of import taxes are ultimately passed on to American consumers and businesses.

At the Economic Club of New York last month, Mr. Trump said that his tariffs “will be bringing in billions and billions of dollars, which will directly reduce our deficits.” He also said he would save money by creating a “government efficiency commission.”

While Ms. Harris has repeatedly attacked Mr. Trump’s plans, neither candidate has made deficit reduction a priority in their campaigns. Instead, both have been one-upping each other with new tax cuts and spending initiatives. The cost estimates come as the United States is already saddled with nearly $36 trillion in debt, with interest costs eclipsing spending on the military and social safety net programs.

For Ms. Harris, the biggest question in her plans is how much of Mr. Trump’s 2017 tax law she would allow to expire at the end of next year. The vice president has said that she will not allow taxes to go up for those earning under $400,000. But it is not clear how she would handle certain deductions that benefit small businesses or tax benefits that businesses get for equipment purchases and research.

Another wild card is how she would approach the state and local tax deduction, known as SALT. Mr. Trump’s tax bill capped the SALT deduction at $10,000 in order to hold down the overall cost of the legislation. That limit is set to expire in 2025, and many Democrats from high-tax blue states, including the Senate majority leader, Chuck Schumer of New York, have pushed for restoring the full deduction. That would add more than $1 trillion to the deficit over 10 years and overwhelmingly benefit rich households.