"[W]ithdrawn employers complained that setting assumptions after the valuation date allowed the trustees to 'retroactively' increase their withdrawal liability. The arbitrators agreed with the employers, but the district court reversed ... With the PBGC's support, the [Solicitor General] advised that that case warranted immediate review because even relatively small changes in assumptions can affect withdrawal liability bills by millions of dollars and 'the dueling rules' can 'open any determination of withdrawal liability to challenge.' " [M & K Employee Solutions, LLC v. Trustees of the IAM National Pension Fund, No. 22-7157 (D.C. Cir Feb. 9, 2024; cert. pet. granted Jun. 30, 2025 No. 23-1209)]   MORE >>