Steven and Roberta Denning Professor of Finance
Senior Fellow, Hoover Institution
Senior Fellow, Stanford Institute for Economic Policy Research

Recent Research

 (with G Buchak,  G Matvos and T Piskorski), 2024

The traditional model of bank-led financial intermediation, where banks issue demandable deposits to savers and make informationally sensitive loans to borrowers, has seen a dramatic decline since 1970s. Instead, private credit is increasingly intermediated through arms-length transactions, such as securitization. This paper documents these trends, explores their causes, and discusses their implications for the financial system and regulation. We document that the balance sheet share of overall private lending has declined from 60% in 1970 to 35% in 2023, while the deposit share of savings has declined from 22% to 13%. Additionally, the share of loans as a percentage of bank assets has fallen from 70% to 55%. We develop a structural model to explore whether technological improvements in securitization, shifts in saver preferences away from deposits, and changes in implicit subsidies and costs of bank activities can explain these shifts. Declines in securitization cost account for changes in aggregate lending quantities. Savers, rather than borrowers, are the main drivers of bank balance sheet size. Implicit banks’ costs and subsidies explain shifting bank balance sheet composition. Together, these forces explain the fall in the overall share of informationally sensitive bank lending in credit intermediation. We conclude by examining how these shifts impact the financial sector’s sensitivity to macroprudential regulation. While raising capital requirements or liquidity requirements decreases lending in both early (1960s) and recent (2020’s) scenarios, the effect is less pronounced in the later period due to the reduced role of bank balance sheets in credit intermediation. The substitution of bank balance sheet loans with debt securities in response to these policies explains why we observe only a fairly modest decline in aggregate lending despite a large contraction of bank balance sheet lending. Overall, we find that the intermediation sector has undergone significant transformation, with implications for macroprudential policy and financial regulation.

(with J Granja, E Jiang, G Matvos and T Piskorski), 2024

In the face of rising interest rates in 2022, banks mitigated interest rate exposure of the accounting value of their assets but left the vast majority of their long-duration assets exposed to interest rate risk. Data from call reports and SEC filings shows that only 6% of U.S. banking assets used derivatives to hedge their interest rate risk, and even heavy users of derivatives left most assets unhedged. The banks most vulnerable to asset declines and solvency runs decreased existing hedges, focusing on short-term gains but risking further losses if rates rose. Instead of hedging the market value risk of bank asset declines, banks used accounting reclassification to diminish the impact of interest rate increases on book capital. Banks reclassified $1 trillion in securities as held-to-maturity (HTM) which insulated these assets book values from interest rate fluctuations. More vulnerable banks were more likely to reclassify. Extending Jiang et al.’s (2023) solvency bank run model, we show that capital regulation could address run risk by encouraging capital raising, but its effectiveness depends on the regulatory capital definitions and can by eroded by the use of HTM accounting. Including deposit franchise value in regulatory capital calculations without considering run risk could weaken capital regulation’s ability to prevent runs. Our findings have implications for regulatory capital accounting and risk management practices in the banking sector.

(with S Agarwal, B Morais and K Shue), 2024

While reliance on human discretion is a pervasive feature of institutional design, human discretion can also introduce costly noise (Kahneman, Sibony, and Sunstein 2021). We evaluate the consequences, determinants, and trade-offs associated with discretion in high-stake decisions assessing bank safety and soundness. Using detailed data on the supervisory ratings of US banks, we find that professional bank examiners exercise significant personal discretion—their decisions deviate substantially from algorithmic benchmarks and can be predicted by examiner identities, holding bank fundamentals constant. Examiner discretion has a large and persistent causal impact on future bank capitalization and supply of credit, leading to volatility and uncertainty in bank outcomes, and a conservative anticipatory response by banks. We identify a novel source of noise: weights assigned to specific issues. Disagreement in ratings across examiners can be attributed to high average weight (50%) assigned to subjective assessment of banks’ management quality, as well as heterogeneity in weights attached to more objective issues such as capital adequacy. Replacing human discretion with a simple algorithm leads to worse predictions of bank health, while moderate limits on discretion can translate to more informative and less noisy predictions.

 (with DeMarzo, Jiang, Krishnamurthy,  Matvos and Piskorski), 2023


  1. New economic conditions have led to insolvency concerns across the banking system.
  2. There are too many banks in this situation to resolve with one-off solutions.
  3. Government backstops and regulatory forbearance risk a repeat of the S&L crisis.
  4. Requiring banks to promptly raise equity capital will both reduce fragility and provide a needed market test to identify truly insolvent banks.
  5. The amount of private capital needed is in the range of $190 to $400 billion.


(with E Jiang, G Matvos and T Piskorski), 2022

Is bank capital structure designed to extract deposit subsidies? We address this question by studying capital structure decisions of shadow banks: intermediaries that provide banking services but are not funded by deposits. We assemble, for the first time, call report data for shadow banks which originate one quarter of all US household debt. We document five facts.

(1) Shadow banks use twice as much equity capital as equivalent banks, but are substantially more leveraged than non-financial firms.

(2) Leverage across shadow banks is substantially more dispersed than leverage across banks.

(3) Like banks, shadow banks finance themselves primarily with short-term debt and originate long-term loans. However, shadow bank debt is provided primarily by informed and concentrated lenders.

(4) Shadow bank leverage increases substantially with size, and the capitalization of the largest shadow banks is similar to banks of comparable size.

(5) Uninsured leverage, defined as uninsured debt funding to assets, increases with size and average interest rates on uninsured debt decline with size for both banks and shadow banks.

Modern shadow bank capital structure choices resemble those of pre-deposit-insurance banks both in the U.S. and Germany, suggesting that the differences in capital structure with modern banks are likely due to banks’ ability to access insured deposits. Our results suggest that banks’ level of capitalization is pinned down by deposit subsidies and capital regulation at the margin, with small banks likely to be largest recipients of deposit subsidies. Models of financial intermediary capital structure then have to simultaneously explain high (uninsured) leverage, which increases with the size of the intermediary, and allow for substantial heterogeneity across capital structures of firms engaged in similar activities. Such models also need to explain high reliance on short-term debt of financial intermediaries.

Selected Data