“Taxes, Lawyers, and the Decline of Witchcraft Trials in France” with Noel D. Johnson. Journal of Law and Economics, February 2014.
“Tax Farming and the Origins of State Capacity in England and France” with Noel D. Johnson. Explorations in Economic History 51,1, pp. 1-20 January 2014
“Prosecution Associations in Industrial Revolution England: Private Providers of Public Goods?” Journal of Legal Studies 41, 1, pp. 95-130 January 2012
“The Transformation of Labor Supply in the Pre-Industrial World” Journal of Economic Behavior and Organization 82, 2, pp. 505-523 February 2012
“Evading the taint of usury: the usury prohibition as a barrier to entry” Explorations in Economic History 47, 4, pp. 420-442 December 2010
Professor Koyama maintains a website for Economic History at George Mason here.