Donald Trump’s presidency may boost the economy—but only in the short run.

The Republican presidential nominee’s plan to lower the corporate tax rate and individual taxes would increase federal debt, according to a study the Penn Wharton Budget Model released in tandem with the Tax Policy Center Monday.

Trump’s tax plan would initially boost gross domestic production by 1.12% and jobs by 1.7 million more than what both would have been in 2018 without his plan. But by 2027, the results of those tax cuts would push GDP 0.43% lower, and cut some 692,000 jobs.

If the government continued spending as much as Trump proposed, the U.S. could lose 11 million jobs by 2040, said Kent Smetters, professor of economics and public policy at Wharton who led the development of the model, in a Monday interview at the university.

“Almost all the bang comes early on” in Trump’s tax plan, Smetters said in the interview. “However, over time, because his plan is unbalanced fiscally, it’s going to produce fairly large deficits.”

Those budget deficits would theoretically crowd out private investments in the long term, leading to an economic slow down.

Democratic presidential nominee Hillary Clinton’s tax plans, however, would be “fairly neutral on the economy in the short run.”

 

Clinton’s tax plan would shrink GDP by 0.19% and add just 282,012 positions by 2018. But by 2027, Clinton’s policies would lead the GDP up by 0.4%, and add 645,161 jobs. By 2040, the U.S. would have added some two million jobs in comparison to what that figure would have been without her.

The Committee for a Responsible Budget has estimated that Trump’s overall budget plans would increase the national debt by some $11.5 trillion.