Employing methods of differential geometry, we propose a new framework for covariance dynamics modeling. Our approach respects the intrinsic geometric properties of the space of covariance matrices and allows their natural evolution. We develop covariance models that exploit either asset returns or realized covariances and propose a new estimation method that minimizes the length of the geodesic between the forecast and the realization. The geodesic length is equivalent to the Fisher information metric under the Gaussian assumption and is deemed a proper measure of similarity between two covariance matrices. Empirical studies involving three data samples and various performance metrics suggest that our models outperform existing ones.

Announcements of stock-financed mergers and acquisitions (M&As) may attract short selling of bidder shares by merger arbitrageurs. We hypothesize that bidders with higher short-selling potential include a higher proportion of cash in their M&A payments to mitigate stock price declines resulting from arbitrage short sales. Consistent with this hypothesis, we find that the ex ante net lending supply of bidder shares has a positive impact on the percentage of cash in public target payments. Further tests, including a placebo analysis of public-to-private deals and an analysis of expected price pressure proxies, corroborate the impact of anticipated arbitrage-related price pressure on payment choice.

We empirically examine the effects of index investing using predictions derived from a Grossman-Stiglitz framework. An exogenous increase in index investing leads to lower information production as measured by Google searches, EDGAR views, and analyst reports, yet price informativeness remains unchanged. These findings are consistent with an equilibrium in which investors choose to gather private information whenever it is profitable. As index investing increases, there are fewer privately-informed active investors (so overall information production drops), but the mix of investors adjusts until the returns to active investing are unchanged. As a result, passive investing does not undermine price efficiency.

Physicians, judges, teachers, and agents in many other settings differ systematically in the decisions they make when faced with similar cases. Standard approaches to interpreting and exploiting such differences assume they arise solely from variation in preferences. We develop an alternative framework that allows variation in preferences and diagnostic skill and show that both dimensions may be partially identified in standard settings under quasi-random assignment. We apply this framework to study pneumonia diagnoses by radiologists. Diagnosis rates vary widely among radiologists, and descriptive evidence suggests that a large component of this variation is due to differences in diagnostic skill. Our estimated model suggests that radiologists view failing to diagnose a patient with pneumonia as more costly than incorrectly diagnosing one without, and that this leads less skilled radiologists to optimally choose lower diagnostic thresholds. Variation in skill can explain 39% of the variation in diagnostic decisions, and policies that improve skill perform better than uniform decision guidelines. Failing to account for skill variation can lead to highly misleading results in research designs that use agent assignments as instruments.

We re-examine the puzzling pattern of lead-lag returns among economically-linked firms. Our results show that investors consistently underreact to information from lead firms that arrives continuously, while information with the same cumulative returns arriving in discrete amounts is quickly absorbed into price. This finding holds across many different types of economic linkages, including shared-analyst-coverage. We conclude that the ǣfrog in the panǥ (FIP) momentum effect is pervasive in co-momentum settings, suggesting that information discreteness (ID) serves as a cognitive trigger that reduces investor inattention and improves inter-firm news transmission.

ABSTRACT We study the determinants of auditor industry specialization, the impact of specialization on fees and audit quality, and a regulator's optimal choice of audit standards in the presence of specialization. In industries with correlated firm values, a specialist auditor enjoys synergies from information spillovers between clients. These spillovers, however, only induce a specialist to decrease audit effort when the cost of effort and the prior precision of the firms' values are low. We derive empirical predictions about the determinants of specialization, and show that specialization benefits firms through lower expected fees and higher audit reporting quality, but only enhances the usefulness of reports to investors when the specialist exerts high audit effort. In a regulated setting, a stricter audit standard affects fees through its impact on specialization. We provide conditions under which standards that maximize firm value will be more strict and less strict when a regulator recognizes synergies. JEL Classifications: C72; D80; D83; L22; M42; M48.

ABSTRACT CEOs of S&P 500 firms that report high non-GAAP earnings relative to GAAP earnings receive substantial unexplained pay. Crucially, this result remains even after controlling for the level of non-GAAP and GAAP earnings. These firms are relatively poor performers (i.e., low GAAP earnings and stock returns) and have less powerful CEOs, consistent with non-GAAP earnings being used as justification when high executive pay is more likely to cause outrage. Additionally, despite the lower GAAP and return performance, these firms are more likely to beat the earnings targets specified in their compensation plans, which likely increases investors' perceptions of core operating earnings and reduces outrage. Indeed, these firms face less dissent from shareholders and proxy advisors, and no additional media scrutiny. Our evidence suggests that the fraction of CEO pay that seems attributable to opportunistic non-GAAP reporting, while limited, is economically meaningful. JEL Classifications: G14; G34; G38; M12; M41.

ABSTRACT We use trade-level data to examine the role of actively managed funds (AMFs) in earnings news dissemination. We find that AMFs are drawn to, and participate disproportionately more in, earnings announcements (EAs) that include bundled managerial guidance. When the two pieces of news are directionally inconsistent, AMFs trade in the direction of future guidance rather than current earnings. AMFs exhibit an ability to discern, and adapt their trading to, the bias in bundled guidance. While AMF trades at EAs are generally more profitable than their non-EA trades, this result reverses when guidance bias is extreme. Overall, we find that increased AMF trading during EAs leads to faster price adjustment. Collectively, these findings suggest that AMFs are sophisticated processors of bundled earnings news, and their trading generally improves market price discovery. JEL Classifications: G12; G14; G23; M41.

Abstract Many development programs that attempt to disseminate improved technologies are limited in duration because of external funding constraints or an assumption of impact sustainability, but there is limited evidence on whether and when terminating such programs is efficient. We provide novel experimental evidence on the impacts of a randomized phaseout of an agricultural extension and subsidy program that promotes improved inputs and cultivation practices among smallholder women farmers in Uganda. We find that phaseout does not diminish the use of either practices or inputs as farmers shift purchases from NGO-sponsored village-based supply networks to market sources. These results indicate that short-term interventions can suffice to trigger persistent effects, consistent with models of technology adoption that emphasize learning from experience.

Abstract The economic analysis of racial discrimination in public accommodations is remarkably limited. To study this issue, we construct a national data set of nondiscriminatory establishments from the Negro Motorist Green Books, a travel guide published from 1936 to 1966 to aid Black Americans in finding nondiscriminatory retail and service establishments. We document patterns in the geographic spread and evolution of Green Book establishments, as well as the correlates of Green Book presence. We find that economic and social measures, as well as state laws relating to racial discrimination and antidiscrimination, were correlated with the provision of nondiscriminatory services. We then use the Green Book data to test whether market conditions and white consumer discrimination led businesses to bar Black customers prior to the Civil Rights Act of 1964. We use plausibly exogenous variation from white World War II casualties and Black migration patterns to isolate the effect of a change in the racial composition of consumers on the growth of nondiscriminatory businesses. We find that the share of nondiscriminatory establishments grew faster in locations with larger increases in the share of the Black population, but the magnitudes were small. These results highlight the importance of federal legislation in ending racial discrimination in public accommodations.