Yet if the House plan resolves some longstanding issues with the corporate tax code, it also creates new ones. Congress has, in effect, set aside $1.5 trillion over the next 10 years to pay for revisions to the tax code, but to keep the cost of the plan to that limit, the Republican leadership is relying on financing gimmicks to phase in some provisions, or put time limits on others.

A proposal that allows companies to immediately deduct business expenses rather than stretching them over a number of years potentially has the most impact on smaller companies that need money to build up or expand their business. Indeed a hefty chunk of the administration’s growth estimates is based on the extra investing it is supposed to cause.

But the proposal has a five-year time limit. “If expensing goes away at the end of 2022, they should not expect any permanent growth effect,” said Mr. Viard of the American Enterprise Institute.

For businesses, predictability about the tax code is as important as any specific alteration. And temporary measures that obscure the costs deter long-term investment. New low rates and breaks will not be sustainable over the long term if they do not provide enough money to run the government.

“If they want to claim credit for the growth effect,” Mr. Viard said, “then they have to claim responsibility for the revenue loss.”

All would-be tax reformers juggle varying goals. They want to entice domestic and foreign companies to invest in the United States, which should, in turn, produce more jobs and stockholder returns.

They want to create a system that is widely judged as fair.

And they need to collect enough revenue to keep the lights on. That includes having the money to cover Social Security payments, antiterrorism measures and disaster relief, as well as maintaining or upgrading the educational, transportation, technological and other systems that undergird the nation’s overall economic strength.