If you own a small business, there’s a lot to like in President Trump’s proposed overhaul of the federal tax code for businesses and individuals.

First of all, Trump is proposing to drop the corporate rate from 35 percent to 15 percent, but the new rate would also apply to small businesses and pass-through entities–partnerships, limited liability companies, S-Corps, startups and the like–who now pay taxes through the personal income tax code, where the top rate is 39.5 percent.

Small businesses–mom-and-pop operations, hedge funds, real-estate partnerships, law firms, etc.–would pay a new business income tax rate within the personal income tax code that matches the 15 percent corporate rate under Trump’s proposed business tax overhaul.

The administration said in a statement that taxing small businesses at current high personal-income tax rates stifles them and also stifles tax reform because efforts to reduce loopholes and deductions to the very rich and special interests end up hitting small businesses and job creators as well.  (The administration proposes to eliminate all deductions from the personal tax code except for mortgage interest, charitable giving and contributions to 401-K retirement plans.)

Other proposed reforms include eliminating the alternative minimum tax and the Obamacare tax on capital gains for high earners.

Director of the National Economic Council Gary Cohn and Treasury Secretary Steven Mnuchin said at a press briefing earlier today that the new lower business and personal rates would provide a stimulus for the economy that would lead to significant GDP growth–at least three percent annually and likely more–a huge number of new jobs and an increase in after-tax wages for workers.

Some skeptics weren’t buying the stimulus argument. Jared Bernstein, who was chief economist for Vice President Joe Biden in the Obama administration, told MSNBC: “No tax cut has ever paid for itself through growth.”

Of course, this is the administration’s opening bid in negotiations with Congress, which will ultimately pass a bill for Trump to sign.  And, just as the Bush tax cuts expired in 2013, these cuts would also expire 10 years after passage. That’s because the Senate is likely to pass any tax bill through reconciliation, which would require only 51 votes, but would also sunset the legislation.

Tax-policy experts cautioned that the outline of the Trump plan on its face would jack up the budget deficit and were skeptical of administration claims the tax cuts would pay for themselves with increased economic growth. The conservative Tax Foundation concluded that a 15 percent corporate tax rate would reduce federal revenues by $2 trillion over the next decade.

The Tax Policy Center, a liberal-leaning research group, said Trump’s plan would add $7 billion to the national debt over the next decade, leading to higher interest payments on the debt and driving up interest rates.

To make up for these losses without specific pay-fors, the economy would have to grow by 5 percent, which is unlikely given past performance. According to government data, the annual growth rate has averaged just 2.9 percent since World War II.  That’s because the U.S. has  a mature economy and, as a result, you don’t get big spurts of economic growth like you see with emerging economies.