Karen Petrou, a Washington-based fiscal policy analyst whose insights shaped banking regulation and monetary strategy for four decades, died on Feb. 21 at age 72 from metastatic breast cancer. As founder of Federal Financial Analytics, she advised major financial institutions and policymakers on the intricacies of banking regulation, including the 2010 Dodd-Frank Act.

Petrou's expertise made her a sought-after speaker before Congress and the Federal Reserve, where she was known for distilling complex rules into their real-world impact on Wall Street and consumers. She gained prominence warning about the unintended consequences of regulatory restrictions, particularly what she termed "complexity risk" from overlapping mandates. Her analyses transcended ideology, criticizing both regulatory laxness during the 2007 crisis and excessive restrictions afterward.

In recent years, Petrou focused on America's wealth inequality, placing significant blame on Federal Reserve policies in her 2021 book "Engine of Inequality: The Fed and the Future of Wealth in America." She also advocated for medical research funding through innovative financial instruments like BioBonds. Petrou, who lost her eyesight to retinitis pigmentosa, often invoked her guide dogs in policy work, comparing financial regulation to guiding complex banks to sound practice.