He specializes in historical political economy, the political economy of development, and international political economy. He is the author of three books and numerous journal articles. His first book is Political Transformations and Public Finances: Europe, 1650-1913 (Cambridge University Press, 2011). His second is State Capacity and Economic Development: Present and Past (Cambridge University Press, 2017). His third is From Warfare to Wealth: The Military Origins of Urban Prosperity in Europe (Cambridge University Press, 2017; coauthored). This book is the winner of the 2018 William H. Riker Best Book Award. In 2016-17, he was the Edward Teller National Fellow at the Hoover Institution at Stanford University.