Norman Lencz and Elizabeth Stieff published "20% Pass-Through Deduction Final Regulations—Some Key Highlights" in Bloomberg Tax Insights on March 4, 2019. Here is an excerpt.
The 20 percent pass-through deduction (the "QBI deduction") for "qualified business income" (QBI) under tax code Section 199A is the Tax Cuts and Jobs Act provision that has probably attracted the most attention from both tax professionals and the general media. While not as dramatic as the corporate tax rate cut from 35 percent to 21 percent, Section 199A can potentially reduce the highest effective marginal tax rate with respect to QBI from 37 percent to 29.6 percent.