Knowledge that Transforms

We study the extent to which time-variation in market betas influence estimates of CAPM alphas. Given the observed variation in conditional market betas, market risk premia, and market variance, the required compensation for conditional market risk can, in theory, be as large as the unconditional equity premium. We implement the conditional CAPM using state-of-the-art methods in a broad global sample. We find that accounting for conditional risk helps explain the return on all the major anomalies we consider and that conditional risk explains two percentage points of alpha for value, investment, and momentum strategies in recent years.

We propose a model of the financial system in which banks are individually prone to runs and connected through fire sales. Strategic complementarities within and across banks amplify each other, making heterogeneity in bank risks a key factor shaping the fragility of each bank and the entire system. As long as different banks are interconnected, an increase in heterogeneity stabilizes all banks. Reductions in asset commonality, bank-specific disclosures, and even broad-based policies such as asset purchases and liquidity requirements can enhance stability by increasing bank heterogeneity.

We study liquidity supply in fragmented markets. Market makers intermediate heterogeneous order flows, trading off spread revenue against inventory costs. Applying our model to payment for order flow (PFOF), we demonstrate that portfolio-based considerations of inventory management incentivize market makers to segment retail orders by siphoning them off-exchange. Banning order flow segmentation reduces total welfare, can make trading more costly for all investors, and can resolve a prisoner's dilemma among market makers. These results differentiate our inventory-based model from the existing information-based theories of PFOF.

We show how uncertainty shapes corporate asset allocation, composition, and productivity using data from the shipping industry. Firms curtail both ship acquisitions and disposals when uncertainty increases, primarily through cuts in new ship orders and ship demolitions — decisions that are costlier to reverse vis-à-vis secondary market transactions. Uncertainty also prompts firms to concentrate their fleets into narrower, less productive portfolios. We corroborate our findings using the 2009–2011 spike in Somali pirate attacks as an uncertainty shock to shipping activity. Uncertainty hampers “creative destruction,” slowing both the adoption of innovation embodied in new capital and the disposal of old capital.

We study the many implications of the Eurosystem collateral framework for corporate bonds. Using data on the evolving collateral eligibility list, we identify the first inclusion dates of bonds and issuers and use these events to find that the increased supply and demand for pledgeable collateral following eligibility (a) increases activity in the corporate securities lending market, (b) lowers eligible bond yields, and (c) affects bond liquidity. Thus, corporate bond lending relaxes the constraint of limited collateral supply and thereby improves market functioning.

Do negative housing shocks lead to persistent changes in household attitudes toward housing and homeownership? We use the residential destruction of Germany during World War II (WWII) as a quasi-experiment and exploit the reasonably exogenous region-by-cohort variation in destruction exposure. We find that WWII-experiencing cohorts from high destruction regions are significantly less likely to be homeowners decades later, controlling for regional differences and household characteristics. Underlying this effect are changes in household attitudes toward homeownership that also extend to preferences for housing consumption, with little or no support for risk preferences, income and wealth effects, or supply-side factors.

We exploit the extinction of the thrift supervisor (OTS) to analyze the effects of supervision on bank lending and bank management. We first show that the OTS replacement resulted in stricter supervision of former OTS banks. Next, we analyze the ensuing lending effects and show that former OTS banks on average increase small business lending by roughly 10 percent. This increase is concentrated in well-capitalized banks and especially in banks that changed management practices following the supervisory transition. These findings suggest that stricter supervision operates not only through the enforcement of loss recognition and capital adequacy, but can also act as a catalyst for operational changes that correct deficiencies in bank management and lending practices, which in turn increase lending.

When race is not directly observed, regulators and analysts commonly predict it using algorithms based on last name and address. In small business lending—where regulators assess fair lending law compliance using the Bayesian Improved Surname Geocoding (BISG) algorithm—we document large prediction errors among Black Americans. The errors bias measured racial disparities in loan approval rates downward by 43%, with greater bias for traditional vs. fintech lenders. Regulation using self-identified race would increase lending to Black borrowers, but also shift lending toward affluent areas because errors correlate with socioeconomics. Overall, using race proxies in policymaking and research presents challenges.

We study the international coordination of bank capital requirements under a host-country rule: the requirement depends on where the borrower, not the bank, is located. In such a regime, countries compete for scarce bank equity capital. Raising a country’s requirement may generate bank capital outflows as well as inflows. We pin down the condition for the sign of the capital flow and the associated externality, and highlight the policy implications. Absent collaboration, overshooting is likely: individual countries have an incentive to increase Basel III’s Counter-Cyclical Capital Buffer too much in good times and cut it too much in bad times.