Several conservative economists, including one of President Donald Trump’s campaign advisors, disputed the White House’s claim that a corporate tax cut Trump signed into law last year has already paid for itself.

Trump’s top economic advisor, Kevin Hassett, highlighted economic stimulus from the tax cuts as part of a presentation to reporters on Monday intended to strengthen Trump’s claim that U.S. economic growth is due to his policies. “I think that the notion that the corporate tax side has about paid for itself is clearly in the data,” Hassett said.