Congress should use dynamic scoring for new infrastructure spending to reflect the fact that it could partly pay for itself, according to a new report co-authored by a progressive and a conservative economist.

In a report commissioned by the McGraw Hill Financial Global Institute, the economists estimate that $100 billion in new infrastructure spending could generate $12.5 billion to $33.1 billion in new taxes over 20 years. That would reduce the need for tax revenues to pay for new roads, bridges, and ports.

That finding will be welcomed by business groups that have called for Congress to boost spending on the nation's aging infrastructure, as well as by Democrats who would like to use the practice of dynamic budget scoring for different government programs.

The report is written by Douglas Holtz-Eakin, a former director of the Congressional Budget Office and president of the right-leaning think tank the American Action Forum, and Michael Mandel, chief economic strategist for the Progressive Policy Institute.

"[F]ederal infrastructure investment should be dynamically scored," the economists write.

Under dynamic scoring, Congress' budget scorekeepers could take into account the added revenues that would come with faster economic growth generated by a change in law. Today, they can only look at the cost side of the equation.

Republicans have sought to increase the use of dynamic scoring for major tax changes.

Democrats, while critical of the GOP's plans for using dynamic scoring for taxes, have argued that the same process should be used to estimate the cost of government spending, including infrastructure spending that could boost growth.

The paper from Holtz-Eakin and Mandel on infrastructure spending estimates the effects of that spending on growth, using data from the Congressional Budget Office and the International Monetary Fund. That data suggests that $100 billion in infrastructure spending could increase national output by $62.5 billion to $165.5 billion over 20 years. The study then assumes a 20 percent effective tax rate on that extra output, leading to an estimate of $12.5 billion to $33.1 billion in new tax revenues.