Detractors quickly piled on a White House study released Monday that foresees incomes getting a boost of $4,000 a year if the corporate tax rate is cut to 20% from 35%.

President Donald Trump has called the 20% rate “very much a red line” as debate heats up in Congress over a tax-reform plan, a chief policy goal he shares with GOP lawmakers. The study, by Trump’s Council of Economic Advisers, says that cutting it to that rate would increase average household income by, “very conservatively,” $4,000 annually. Read the CEA study.

Among assumptions cited is that a tax cut will lead to capital investments by corporations, and in turn, that labor demand — and worker wages — will increase. “Capital deepening, which brings additional returns to the owners of capital, brings returns to workers as well,” says the study from the CEA, which is headed by Kevin Hassett.

Jared Bernstein, who was chief economist to former Vice President Joe Biden, called the study “the latest example of non-credible, trickle-down fairy dust.” He’s skeptical that corporate tax cuts boost productivity, and says that one can’t assume higher productivity boosts wages.

Another critique comes from Joe Rosenberg of the Tax Policy Center. Rosenberg said he doesn’t disagree that corporate tax cuts can help lift wages. “I just think the magnitude of it is very, very high,” he says of the $4,000 figure. The White House study says the boost could be more than $9,000 under different estimates.

Rosenberg also says the study is based on a “selective review” of economic literature. That literature itself has been hotly debated. Last month, the Treasury Department took down an economic analysis from 2012 which argued that workers pay 18% of the corporate tax rate, and business owners pay the rest.

Jason Furman, who held Hassett’s position in the Obama administration, said the study puts the percentage of the corporate rate paid by labor at 250%.

Trump and his chief lieutenants including Treasury Secretary Steven Mnuchin have been trying to sell the tax plan as a boon to the middle class, versus the wealthy. Trump’s re-election operation touted the $4,000 figure in an email to supporters on Monday. “Over and over again, voters across the country are telling us that they want Republicans in Congress to back President Trump’s solutions to Make America Great Again, especially through his tax reform plan that will provide a $4,000 pay raise for middle class families,” the email read in part.

Speaking on CNBC on Monday, Hassett said economic literature is “consistent with the story that the president’s been saying: that if we cut corporate taxes, we lure businesses back here, and the businesses drive up wages.”

Hassett has previously argued that ending the taxation of corporations’ foreign earnings and cutting the corporate rate could result in a $4,000 boost over eight years.

Trump has been trying to bring some Democrats on board as he seeks to push a tax overhaul through Congress. But on Monday the Senate’s top Democrat slammed the study.

“President Trump complains about fake news,” said Senate Minority Leader Charles Schumer. “This fake math is as bad as any of the so-called fake news he has complained about.”