Ripley was the Vice President of the American Economics Association 1898, 1900, and 1901, and was elected president of it in 1933. From 1919 to 1920, he served as the chairman of the National Adjustment Commission of the United States Shipping Board, and from 1920 to 1923, he served with the Interstate Commerce Commission. In 1921, he was ICC special examiner on the construction of railroads. There, he wrote the ICC's plan for the regional consolidation of U.S. railways, which became known as the "Ripley Plan". In 1929, the ICC published Ripley's Plan under the title "Complete Plan of Consolidation". Numerous hearings were held by the ICC regarding the plan under the topic of "In the Matter of Consolidation of the Railways of the United States into a Limited Number of Systems".