The bipartisan tax bill contains a critical fix to spur American innovation

For nearly 70 years, American businesses were permitted to deduct 100 percent of research and development expenses from taxable income in the year those expenses were incurred. This favorable tax treatment promoted innovation by incentivizing investments in research and technological advancement — leading to countless scientific breakthroughs, powering economic growth and producing many significant commercial and military advantages for the U.S.

But when Congress passed the Tax Cuts and Jobs Act (TCJA) in 2017...