ProPublica reported the disproportionate audit focus on lower-income families in April. Lawmakers confronted IRS Commissioner Charles Rettig about the emphasis, citing our stories, and Sen. Ron Wyden, D-Ore., asked Rettig for a plan to fix the imbalance. Rettig readily agreed…

On the one hand, the IRS said, auditing poor taxpayers is a lot easier: The agency uses relatively low-level employees to audit returns for low-income taxpayers who claim the earned income tax credit. The audits — of which there were about 380,000 last year, accounting for 39% of the total the IRS conducted — are done by mail and don’t take too much staff time, either. They are “the most efficient use of available IRS examination resources,” Rettig’s report says.

On the other hand, auditing the rich is hard. It takes senior auditors hours upon hours to complete an exam. What’s more, the letter says, “the rate of attrition is significantly higher among these more experienced examiners.” As a result, the budget cuts have hit this part of the IRS particularly hard.