Ben, you oversimplify. While it’s true that the unemployment rate is very low, that’s not necessarily an accurate picture of the job market, and it’s certainly not clear that the Trump tax cut is responsible for it. I just read an article in Quartz about something called the Job Quality Index. The JQI measures the quality of jobs, and it doesn’t paint the rosy picture that the unemployment rate does.
To answer your question about how to discount the taxes if those who don’t pay taxes, we already refundable credits like the Earned Income Credit.
As for the effect of the Trump tax cut on different groups, can you find documentary evidence to challenge this statement? “In general, higher income households receive larger average tax cuts as a percentage of after-tax income, with the largest cuts as a share of income going to taxpayers in the 95th to 99th percentiles of the income distribution.”
Don’t forget that the deficit has increased greatly due to the tax cut.