Sudden Firm Exit (2025) with Connor Powell

A model that combines Hopenhayn (1992) and Klette and Kortum (2004) can better account for large firm exit than either model and implies a much larger role for new variety creation and creative destruction as sources of economic growth.

Immigration and Productivity: Unpacking the Role of Spatial Sorting (2025) with Jan Auerbach, Elisa Keller, and Rish Singhania 

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Foreign-born workers increase aggregate productivity by overcoming the birth-state bias of US-born.

From Population Growth to Firm Demographics (2022) with Hugo Hopenhayn and Rish Singhania. Econometrica                                                                                                                                                                                               

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    • Online Appendix

    • BibTeX file

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    • Coverage: Marginal Revolution, Growth Economics Blog, The New York Times, Washington Post, Speech by the Philly Fed President, and in Fully Grown: Why a Stagnant Economy is a Sign of Success.

The baby boom provides a unified quantitative explanation for a set of apparently disparate long-term trends, such as the rise in concentration, the fall of the labor share, and the decline of entrepreneurship.

The Role of Corporate Taxes in the Decline of the Startup Rate (2022) with Rish Singhania. Economic Inquiry                                                                                                                                                               

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While a decline in corporate taxes can generate a decline in the startup rate, it is unlikely that this decline played a major role.

Optimal Taxation with Risky Human Capital (2019) with Marek Kapička. American Economic Journal: Macroeconomics 

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    • Online Appendix

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Schooling expenditures should be highly subsidized - due to their inherent fiscal externality - but less than fully - due to moral hazard disincentives on learning effort.

Bankruptcy and Cross-Country Differences in Productivity (2019). Journal of Economic Behavior and Organization

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Better bankruptcy laws raise aggregate productivity by allowing lenders to lend more and to more productive firms.

Nelder-Mead Simplex Minimization Routine for Large-Scale Problems: A Distributed Memory Implementation (2014) with Kyle Klein.  Computational Economics

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    • BibTeX file

    • C++ codes

    • Implementation in R (by Chris Cheung)

Proposes an implementation of the Nelder-Mead optimization routine for supercomputers.