Income Inequality in Cook County, IL was 20.72737 Ratio in January of 2022, according to the United States Federal Reserve. Historically, Income Inequality in Cook County, IL reached a record high of 20.72737 in January of 2022 and a record low of 17.62601 in January of 2010. Trading Economics provides the current actual value, an historical data chart and related indicators for Income Inequality in Cook County, IL - last updated from the United States Federal Reserve on May of 2024.