Welcome! I am an IES Postdoctoral Fellow in the Economics Department at Princeton University. I completed my PhD in Economics at the University of Chicago in 2025. My research interests are in Urban and Spatial Economics, International Trade, and Econometrics.

My CV is available here.

My email is hierons@princeton.edu

Job Market Paper

Spreading the Jam: Optimal Congestion Pricing in General Equilibrium
Road traffic leads to an externality: drivers do not account for the time cost they impose on others. In this paper, I study the potential gains from optimal congestion pricing. I develop an urban general equilibrium model which features residential and workplace location, travel mode, and route choices with congestion. The attractiveness of workplaces and residences is also determined endogenously. I provide conditions for the uniqueness of both the competitive equilibrium and the first best planner’s problem and characterize the tax instruments needed to decentralize it. I show how the model can be solved with arbitrary taxes, including congestion toll zones of the kind often implemented in practice. I estimate the model's parameters in an application to New York City. I find that the first best tax policy would realize gains of $0.77 per person per day or a total of $21.7 million per week. Over a third of the gains from optimal congestion pricing at the individual link level can be achieved by a congestion zone that covers only lower Manhattan. I decompose these gains along different margins of adjustment, finding that mode choice is a key driver of the results with driver route choice and general equilibrium location choices also playing a non-negligible role.

Work in Progress

Survival of the Fit Test: Can Experiments Validate Structural Models?

With Omkar Katta and Alexander Torgovitsky