Johan HOMBERT Associate Professor of Finance, HEC Paris Email: hombert@hec.fr Curriculum Vitae Blog: I post short pedagogical articles explaining how to use tools learned in finance classes to understand current events in financial markets. Read the blog here

Working Papers

Incentive Constrained Risk Sharing, Segmentation, and Asset Pricing with Bruno Biais and Pierre-Olivier Weill R&R American Economic Review When imperfect asset pledgeability creates endogenous borrowing constraints, asset markets are endogenously segmented, assets trade at a discount relative to replicating portfolios of derivatives, and expected excess returns are concave in beta. [pdf] Can Risk be Shared Across Investor Cohorts? Evidence from a Popular Savings Product with Victor Lyonnet R&R Review of Financial Studies Private implementation of inter-cohort risk sharing on a large scale: savings products sold by life insurers in France transfer 0.8% of GDP across cohorts of investors every year. [pdf] Technology Boom, Labor Reallocation, and Human Capital Depreciation with Adrien Matray The late 1990s tech bubble attracted many high-skill young workers, who initially enjoyed higher wages. In the long run, however, they end up earning 6% less than individuals who started in other sectors. [pdf]

Publications

Can Unemployment Insurance Spur Entrepreneurial Activity? Evidence from France with Antoinette Schoar, David Sraer and David Thesmar Journal of Finance, 2020 Giving unemployment benefits to entrepreneurs leads to the entry of small firms which eventually grow, and fosters creative destruction. [pdf] [supplementary appendix] Anticompetitive Vertical Mergers Waves with Jerome Pouyet and Nicolas Schutz Journal of Industrial Economics, 2019 Vertical mergers relax competition. [pdf] [supplementary appendix] Can Innovation Help U.S. Manufacturing Firms Escape Import Competition from China? with Adrien Matray Journal of Finance, 2018 U.S. manufacturing firms that have invested in R&D are more resilient to trade shocks. [pdf] [supplementary appendix] The Competitive Effect of a Bank Megamerger on Credit Supply with Henri Fraisse and Mathias Le Journal of Banking and Finance, 2018 A merger between two large European banks reduces credit supply to SMEs. [pdf] The Real Effects of Lending Relationships on Innovative Firms and Inventor Mobility with Adrien Matray Review of Financial Studies, 2017 Hurting lending relationships stiffles innovation and leads to reallocation of inventors across firms and across states. [pdf] [vox summary] News Trading and Speed with Thierry Foucault and Ioanid Rosu Journal of Finance, 2016 Traders who observe news faster than others have extremely volatile ("high-frequency") strategies. [pdf] [supplementary appendix] Equilibrium Pricing and Trading Volume under Preference Uncertainty with Bruno Biais and Pierre-Olivier Weill Review of Economic Studies, 2014 Asset pricing when traders make decisions under preference uncertainty, because their financial firms face challenges collecting, processing, and disseminating information. [pdf] [supplementary appendix] Overcoming Limits of Arbitrage: Theory and Evidence with David Thesmar Journal of Financial Economics, 2014 Arbitrageurs can choose their capital structure to take advantage of temporary mispricing: theory and evidence. [pdf] Upstream Competition between Vertically Integrated Firms with Marc Bourreau, Jerome Pouyet and Nicolas Schutz Journal of Industrial Economics, 2011 Competition between vertically integrated firms can fail. [pdf] [supplementary appendix]

Other publications

Does Unemployment Insurance Change the Selection into Entrepreneurship? with Antoinette Schoar, David Sraer and David Thesmar NBER book Measuring Entrepreneurial Businesses: Current Knowledge and Challenges, 2017 Giving unemployment benefits to entrepreneurs does not deteriorate the success potential of start-ups. [pdf]

Teaching

Financial Markets Master in Management, HEC Paris I write short articles posted on this blog showing how to use tools learned in the Financial Markets class to explain current events in financial markets Finance for Data Scientists MSc Data Science for Business, Polytechnique – HEC Paris Microeconomics 1 Master in Economics, IP Paris – HEC Paris