He is the author of “The Permanent Effects of Innovation on Financial Depth: Theory and U.S. Historical Evidence from Unobservable Components Models,” Journal of Monetary Economics (October 1998), “Jacksonian Monetary Policy, Specie Flows, and the Panic of 1837,” Journal of Economic History (June 2002), and “Historical Perspectives on Financial Development and Economic Growth,” Review, Federal Reserve Bank of St. Louis (July/August 2003).