Assistant Professor of Economics, Columbia University
1131 International Affairs Building, NY 10027
mg3901@columbia.edu

Feel free to pronounce my name the American way (Matthew). My pronouns are he/his/him.

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Working Papers

• Asset-Price Redistribution with A. Fagereng, E. Gouin-Bonenfant, M. Holm, B. Moll, and G. Natvik
  Over the last several decades, there has been a large increase in valuations across many asset classes. These rising valuations had important effects on the distribution of wealth. However, little is known regarding their effect on the distribution of welfare . To make progress on this question, we derive a sufficient statistic for the welfare effect of a change in asset valuations, which depends on the present value of an individual’s net asset sales. We estimate this quantity using panel microdata covering the universe of financial transactions in Norway from 1994 to 2015. We find that rising asset valuations had important redistributive effects: they redistributed welfare from the young towards the old and from the poor towards the wealthy.
• A Q-Theory of Inequality with E. Gouin-Bonenfant
  R&R, Econometrica
  We study the effect of interest rates on wealth inequality. While low rates decrease the average growth rate of existing fortunes, they increase the growth rate of new fortunes by making it cheaper to raise capital. To understand which effect dominates, we derive a sufficient statistic for the effect of interest rates on the Pareto exponent of the wealth distribution: it depends on the average equity issuance rate and leverage of individuals reaching the right tail of the distribution. We estimate this sufficient statistic using new data on the trajectory of top fortunes in the U.S. We conclude that the secular decline in discount rates has played a key role in the recent increase of top wealth inequality.
• Sorting Out the Real Effects of Credit Supply with B. Chang and H. Hong
  R&R, Journal of Financial Economics
  We show that banks that cut lending more during the Great Recession lent to riskier firms. To examine the equilibrium effect of this sorting pattern, we build an assignment model in which banks have heterogeneous holding costs and firms have heterogeneous risks. In the model, loan volume declines more when negative credit supply shocks are concentrated on low holding cost banks like Lehman Brothers relative to high holding cost banks. We then use our model to recover the change in the distribution of bank holding costs during the Great Recession and quantify its effect on aggregate loan volume.
• The Dynamics of Asset Prices and Wealth Inequality
  Wealthy households disproportionaly invest in risky assets; as a result, fluctuations in asset prices generate fluctuations in wealth inequality. To examine the equilibrium effect of these fluctuations, I build an asset pricing model in which agents have heterogeneous exposures to aggregate shocks. While the wealth distribution implied by the model is stochastic, it still exhibits a thick right tail, which depends on the geometric average of the portfolio returns of wealthy households. The model, calibrated the model on the saving rate and wealth exposure of households at the top of the wealth distribution, can account for a large fraction of the dynamics of asset prices and wealth inequality over the 20th century.

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Publications

• Decomposing the Growth of Top Wealth Shares
  Accepted, Econometrica
  [Data] [Stata Program]
  Top wealth inequality has dramatically increased over the last fourty years. To understand why, I propose an accounting framework that decomposes the growth of the share of aggregate wealth owned by a top percentile into three terms: a within term, which is the average growth of individuals in the top percentile relative to the economy; a between term, which accounts for the flow of existing individuals in and out the top percentile; and a demography term, which accounts for death and population growth. Evidence from the Forbes 400 list suggests that the between term accounts for about half of the rise in top wealth inequality.
• Bank Exposure to Interest-Rate Risk and the Transmission of Monetary Policy with A. Landier, D. Sraer, and D. Thesmar
  Journal of Monetary Economics (2021)
  The cash-flow exposure of banks to interest rate risk, or income gap, is a significant determinant of the transmission of monetary policy to bank lending and real activity. When the Fed Funds rate rises, banks with a larger income gap generate stronger earnings and contract their lending by less than other banks. This finding is robust to controlling for factors known to affect the transmission of monetary policy to bank lending. It also holds on loan-level data, even when we control for firm-specific credit demand. When monetary policy tightens, firms borrowing from banks with a larger income gap reduce their investment by less than other firms.