Comment by rawgabbit

The only logic was to make the Trump 2017 tax cuts look "revenue neutral". They were cooking the books so the CBO would give the tax cuts a passing grade.

https://americansfortaxfairness.org/ways-means-trump-tax-law... Quote: Corporations have traditionally been allowed to deduct all of their research expenses in the year incurred, even though a lot of research pays off slowly so its costs should similarly be written off over time. Adopting this position, and as a way to partially pay for its big corporate-rate cut, the Trump-GOP tax law decreed that starting in 2022 companies would have to write off research and experimentation expenses gradually: over five years for domestic research, 15 years for foreign. This requirement to “amortize” the expense over time reduces the value of the deduction, increasing corporations’ taxable income and requiring them to pay more in income taxes upfront. The Ways & Means legislation proposes to retroactively reverse this provision.