Stefano Giglio
Professor of Finance, Yale School of Management
NBER Research Associate
CEPR Research Affiliate
Working Papers
Biodiversity Risk, with Johannes Stroebel, Theresa Kuchler, and Xuran Zeng, April 2023
Northwestern University Moskowitz Prize for sustainable finance research
Berkeley Haas Sustainable Business Research Prize
We explore the effects of physical and regulatory risks related to biodiversity loss on economic activity and asset values. We first develop a news-based measure of aggregate biodiversity risk and analyze how it varies over time. We also construct and publicly release several firm-level measures of exposure to biodiversity risk, based on textual analyses of firms’ 10-K statements, a large survey of financial professionals, regulators, and academics, and the holdings of biodiversity-related funds. Exposures to biodiversity risk vary substantially across industries in a way that is economically sensible and distinct from exposures to climate risk. We find evidence that biodiversity risks already affect equity prices: returns of portfolios that are sorted on our measures of biodiversity risk exposure covary positively with innovations in aggregate biodiversity risk. However, our survey indicates that market participants do not perceive the current pricing of biodiversity risks to be adequate.
Four Facts about ESG Beliefs and Investor Portfolios, with Matteo Maggiori, Johannes Stroebel, Zhenhao Tan, Stephen Utkus, and Xiao Xu, April 2023
Northwestern University Moskowitz Prize for sustainable finance research (honorable mention)
We analyze survey data on ESG beliefs and preferences in a large panel of retail investors linked to administrative data on their investment portfolios. The survey elicits investors’ expectations of long- term ESG equity returns and asks about their motivations, if any, to invest in ESG assets. We document four facts. First, investors generally expected ESG investments to underperform the market. Between mid-2021 and late-2022, the average expected 10-year annualized return of ESG investments relative to the overall stock market was −1.4%. Second, there is substantial heterogeneity across investors in their ESG return expectations and their motives for ESG investing: 45% of survey respondents do not see any reason to invest in ESG, 25% are primarily motivated by ethical considerations, 22% are driven by climate hedging motives, and 7% are motivated by return expectations. Third, there is a link between individuals’ reported ESG investment motives and their actual investment behaviors, with the highest ESG portfolio holdings among individuals who report ethics-driven investment motives. Fourth, financial considerations matter independently of other investment motives: we find meaningful ESG holdings only for investors who expect these investments to outperform the market, even among those investors who reported that their most important ESG investment motives were ethical or hedging reasons.
Prediction When Factors are Weak, with Dacheng Xiu and Dake Zhang, March 2023
In macroeconomic forecasting, principal component analysis (PCA) has been the most prevalent approach to the recovery of factors, which summarize information in a large set of macro predictors. Nevertheless, the theoretical justification of this approach often relies on a convenient and critical assumption that factors are pervasive. To incorporate information from weaker factors, we propose a new prediction procedure based on supervised PCA, which iterates over selection, PCA, and projection. The selection step finds a subset of predictors most correlated with the prediction target, whereas the projection step permits multiple weak factors of distinct strength. We justify our procedure in an asymptotic scheme where both the sample size and the cross-sectional dimension increase at potentially different rates. Our empirical analysis highlights the role of weak factors in predicting inflation, industrial production growth, and changes in unemployment.
What Drives Booms and Busts in Value?, with John Campbell and Christopher Polk, November 2023
Value investing delivers volatile returns, with large drawdowns during both market booms and busts. This paper interprets these returns through an intertemporal CAPM, which predicts that aggregate cash flow, discount rate, and volatility news all move value returns. We document that indeed these shocks explain a large fraction of quarterly value returns over the last 60 years. We also distinguish between the intra-industry and inter-industry components of value, showing that the ICAPM explains the former better. Finally, we develop a novel methodology to perform this decomposition at the daily frequency, using it to interpret value returns during the Covid-19 pandemic.
Risk preferences implied by synthetic options, with Ian Dew-Becker, October 2023
The historical returns on equity index options are well known to be strikingly negative. That is typically explained either by investors having convex marginal utility over stock returns (e.g. crash/variance aversion) or by intermediaries demanding a premium for hedging risk. This paper examines the consistency of those explanations with returns on dynamically replicated, or synthetic, options. Theoretically, it derives conditions under which convex marginal utility leads synthetic options to also have negative excess returns. Empirically, synthetic options have CAPM alphas near zero over the period 1926-2022, in stark contrast to exchange-traded options. Over the last 15 years, returns on traded options have converged to those on synthetic options - with the variance risk premium shrinking towards zero - while various drivers of the cost and risk of hedging options exposures have declined, consistent with a model in which intermediaries drive option prices.
A Quantity-Based Approach to Constructing Climate Risk Hedge Portfolios, with Georgij Alekseev, Quinn Maingi, Julia Selgrad and Johannes Stroebel, June 2022
Best Paper in Asset Pricing at the 2022 SFS Cavalcade
Two Sigma Award, Best Paper on Investment Management, 2022 WFA Meetings
We propose a new methodology to build portfolios that hedge climate change risks. Our quantity-based approach explores how mutual funds holdings change when the fund adviser experiences a local extreme heat event that shifts beliefs about climate risks. We use the observed trading behavior to predict how investors will reallocate their capital when "global" climate news shocks occur, which shift the beliefs and asset demands of many investors simultaneously and thus move equilibrium prices. We show that a portfolio that holds stocks that investors tend to buy after experiencing a local heat shock appreciates in value in periods with aggregate climate news shocks. Our quantity-based approach yields superior out-of-sample hedging performance compared to traditional methods of identifying hedge portfolios. The key advantage of the quantity-based approach is that it learns from cross-sectional trading responses rather than time-series price information, which is limited in the case of climate risks. We also demonstrate the efficacy and versatility of the quantity-based approach by constructing successful hedge portfolios for aggregate unemployment and house price risk.
Credit Default Swap Spreads and Systemic Financial Risk, April 2014
Runner-up, Ieke van den Burg Prize for Research on Systemic Risk 2015
This paper measures the joint default risk of financial institutions by exploiting information about counterparty risk in credit default swaps (CDS). A CDS contract written by a bank to insure against the default of another bank is exposed to the risk that both banks default. From CDS spreads we can then learn about the joint default risk of pairs of banks. From bond prices we can learn the individual default probabilities. Since knowing individual and pairwise probabilities is not sufficient to fully characterize multiple default risk, I derive the tightest bounds on the probability that many banks fail simultaneously.
Publications
29. Recent Developments in Financial Risk and the Real Economy, with Ian Dew-Becker, March 2024
Annual Review of Financial Economics, forthcoming
28. Test Assets and Weak Factors, with Dacheng Xiu and Dake Zhang
Journal of Finance, forthcoming
[Code]
27. Equity Term Structures without Dividend Strips Data, with Bryan Kelly and Serhiy Kozak
Journal of Finance, forthcoming
[Data]
26. Cross-sectional uncertainty and the business cycle: evidence from 40 years of options data, with Ian Dew-Becker
American Economic Journal: Macroeconomics (2023), 15 (2): 65-96
[Data]
25. The effect of climate risks on the interactions between financial markets and energy companies, with Arthur van Benthem, Edmund Crooks, Eugenie Schwob and Johannes Stroebel
Nature Energy (2022), 7: 690–697
24. Factor Models, Machine Learning, and Asset Pricing, with Bryan Kelly and Dacheng Xiu
Annual Review of Financial Economics (2022), 14: 337-68
23. The Collateral Rule: Evidence from the Credit Default Swap Market, with Agostino Capponi, Allen Cheng, Chuan Du, and Richard Haynes
Journal of Monetary Economics (2022), 126: 58-86
22. Climate Change and Long-Run Discount Rates: Evidence from Real Estate, with Matteo Maggiori, Krishna Rao, Johannes Stroebel, and Andreas Weber
Review of Financial Studies (2021), 34(8): 3527-3571
RFS Editor's Choice Article
RFS Michael Brennan Best Paper Award Runner Up 2022
21. Asset Pricing with Omitted Factors, with Dacheng Xiu
Journal of Political Economy (2021), 129(7): 1947-1990
Lead Article
Best Paper Prize at the 2017 European Financial Association conference
[Online Appendix] [Code]
20. The joint dynamics of investor beliefs and trading during the COVID-19 crash, with Matteo Maggiori, Johannes Stroebel and Stephen Utkus
PNAS (2021), 118(4)
Previously circulated as "Inside the Mind of a Stock Market Crash"
19. Five Facts About Beliefs and Portfolios, with Matteo Maggiori, Johannes Stroebel, and Steven Utkus
American Economic Review (2021), 111 (5): 1481-1522
2021 AQR Insight Award (Distinguished Paper)
Best Behavioral Finance Paper, Midwest Finance Association Meetings 2020
Yuki Arai Faculty Research Prize for Finance 2019
18. Climate Finance, with Bryan Kelly and Johannes Stroebel
Annual Review of Financial Economics (2021), 13:15-36
17. Hedging macroeconomic and financial uncertainty and volatility, with Ian Dew-Becker and Bryan Kelly
Journal of Financial Economics (2021), 142: 23-45
[Data] [Online Appendix]
16. Thousands of alpha tests, with Yuan Liao and Dacheng Xiu
Review of Financial Studies (2021), 34(7): 3456-3496
[Online Appendix] [Code]
15. Taming the Factor Zoo: a Test of New Factors, with Guanhao Feng and Dacheng Xiu
Journal of Finance (2020), 75(3): 1327-1370
AQR Insight Award 2018, First Prize
14. Uncertainty Shocks as Second-Moment News Shocks, with David Berger and Ian Dew-Becker
Review of Economic Studies (2020), 87(1): 40-76
[Data] [Online Appendix]
(Previous Title: "Contractionary Volatility or Volatile Contractions"?)
13. Hedging Climate Change News, with Robert Engle, Bryan Kelly, Heebum Lee and Johannes Stroebel
Review of Financial Studies (2020), 33(3): 1184-1216
[Data]
12. An Intertemporal CAPM with Stochastic Volatility, with John Campbell, Christopher Polk and Bob Turley
Journal of Financial Economics (2018), 128(2): 207-233
Lead article
Fama-DFA Prize for the Best Paper Published in the Journal of Financial Economics (Asset Pricing), 2018
11. Excess Volatility: Beyond Discount Rates, with Bryan Kelly
Quarterly Journal of Economics (2018), 133(1): 71-127
Finalist, AQR Insight Award, 2016
Napa Conference Best Paper Award, 2016
10. The Price of Variance Risk, with Ian Dew-Becker, Anh Le and Marius Rodriguez
Journal of Financial Economics (2017), 123(2): 225-250
Lead article
[Data] [Online Appendix]
9. Asset Pricing in the Frequency Domain: Theory and Empirics, with Ian Dew-Becker
Review of Financial Studies (2016), 29(8): 2029-2068
[Online Appendix] [Coverage: VoxEU]
8. No-Bubble Condition: Model-Free Tests in Housing Markets, with Matteo Maggiori and Johannes Stroebel
Econometrica (2016), 84(3): 1047-1091
[Online Appendix] [Reply] [Coverage: VoxEU]
7. Systemic Risk and the Macroeconomy: An Empirical Evaluation, with Bryan Kelly and Seth Pruitt
Journal of Financial Economics (2016), 119(3): 457-471
Lead article
Fama-DFA Prize for the Best Paper Published in the Journal of Financial Economics (Asset Pricing), 2016
Q-Group Roger F. Murray Prize (3rd prize), 2015
[Online Appendix] [Data] [Coverage: MoneyAndBanking.com; VoxEU; BFI]
6. A Review of Long-Run Discounting: evidence from Housing Markets, with Matteo Maggiori
Rivista di Politica Economica (2016), 4, 7-36 (not refereed)
5. Very Long-Run Discount Rates, with Matteo Maggiori and Johannes Stroebel
Quarterly Journal of Economics (2015), 130(1): 1-53
QJE Lead Article
QJE Editor's Choice article
Jacob Gold & Associates Best Paper Prize, ASU Sonoran Winter Finance Conference, 2014
NYU Glucksman Institute Faculty Research Prize for the Best Paper in Finance, 2015
[Online Appendix] [NBER WP Version] [Data]
[Coverage: Forbes ; Economist, May 2014 ; National Review ; NBER Digest ; VoxEU; Economist, April 2015]
4. No News is News: Do Markets Underreact to Nothing?, with Kelly Shue
Review of Financial Studies, (2014), 27(12): 3389-3440
Lead Article
Winner of the UBS Global Asset Management Award for Research in Investments, FRA Meeting 2012
3. Hard Times, with John Campbell and Christopher Polk
Review of Asset Pricing Studies (2013), 3(1): 95-132
2. Intangible Capital, Relative Asset Shortages, and Bubbles, with Tiago Severo
Journal of Monetary Economics (2012), 59: 303-317
1. Forced Sales and House Prices, with John Campbell and Parag Pathak
American Economic Review (2011), 101(5): 2108–31