After GOP lawmakers and the Trump administration slashed the corporate income tax rate from 35 percent to 21 percent two years ago, corporate tax revenue as a share of gross domestic product is lower in the United States than any of 30 developed countries — with the exception of Latvia.

That's the conclusion of Jason Furman, a Harvard University economics professor who testified before the House Ways and Means Committee Tuesday. “Corporate revenue collections are very low” both historically and compared to other advanced economies, said Furman, who served as chairman of the Council of Economic Advisers under President Barack Obama.

While there are estimates that corporate tax collections will grow slightly as a percentage of GDP in coming years, that likelihood will evaporate if business provisions in the 2017 tax law are made permanent, Furman added, chiefly those allowing more generous equipment expensing.

Ways and Means Democrats held the hearing to highlight unexpectedly low corporate tax collections following the big tax cut, which took effect in 2018. Republicans countered that making U.S. corporate tax rates internationally competitive ended the relocations of U.S. corporations overseas, and has been key to an economic boom that President Donald Trump has called the greatest in American history.

At the time the tax overhaul was being considered, the Joint Committee on Taxation estimated that the corporate tax rate cut would cost $1.35 trillion over 10 years. But tax collections following the cut suggest the hit was even bigger, as corporate tax collections plummeted 31 percent to $205 billion in 2018, $38 billion below estimates. The $230 billion collected in 2019 was $46 billion below earlier JCT predictions.