John Pfaff is a Professor of Law at Fordham Law School where he teaches criminal law, sentencing law, and law and economics. His research focuses primarily on empirical matters related to criminal justice, especially criminal sentencing. He has paid particular attention to trying to understand the causes of the unprecedented 40-year boom in US incarceration rates.

His work has shown that many of the most politically popular reforms put forth to reverse mass incarceration in the US—legalizing certain drugs, imposing shorter prison sentences, and limiting the power of private prisons—will have far less impact than people assume. In particular, it has illuminated the previously-underappreciated role that prosecutorial discretion has played in driving up prison populations, especially since crime rates started falling in the 1990s. It has also demonstrated that real reform requires asking hard questions about how we punish people convicted of violence and how we correct a host of political failures that contributed to the mass incarceration epidemic.

John's findings have been featured in major publications including The New York Times, Wall Street Journal, the Economist, and the New Yorker, as well as prestigious legal opinions and law review articles, including one written by former President Barack Obama.

Before coming to Fordham, John was the John M. Olin Fellow at the Northwestern University School of Law and clerked for Judge Stephen F. Williams on the US Court of Appeals for the DC Circuit. He received both his JD and his PhD in Economics from the University of Chicago.

John recently published his first book, "Locked In: The True Causes of Mass Incarceration—and How to Achieve Real Reform."