Learning and the Disappearing Association Between Governance and Returns

In an important and influential work, Gompers, Ishii, and Metrick (2003) show that a trading strategy based on an index of 24 governance provisions (G-Index) would have earned abnormal returns during the 1991-1999 period, and this intriguing finding has attracted much attention ever since it was reported. We show that the G-Index (as well as the E-Index based on a subset of the six provisions that matter the most) was no longer associated with abnormal returns during the period of 2000-2008, or any sub- periods within it, and we provide evidence consistent with the hypothesis that the disappearance of the governance-returns association was due to market participants’ learning to appreciate the difference between firms scoring well and poorly on the governance indices. Consistent with the learning hypothesis, we document that (i) attention to corporate governance from the media, institutional investors, and researchers has exploded in the beginning of the 2000s and remained on a high level since then, and (ii) until the beginning of the 2000s, but not subsequently, market participants were more positively surprised by the earning announcements of good-governance firms than by those of poor-governance firms. Our results are robust to excluding new economy firms or to focusing solely on firms in non- competitive industries. While the G and E indices could no longer generate abnormal returns in the 2000s, their negative association with Tobin’s Q persists and they thus remain valuable tools for researchers, policymakers, and investors.

Staggered Boards and the Wealth of Shareholders: Evidence from Two Natural Experiments

While staggered boards have been documented to be negatively correlated with firm valuation, such association might be due to staggered boards either bringing about lower firm value or merely reflecting the tendency of low-value firms to have staggered boards. In this paper, we use two natural experiments to shed light on the causality question. In particular, we focus on two recent court rulings, separated by several weeks, that affected in opposite directions the antitakeover force of staggered boards: (i) a ruling by the Delaware Chancery Court approving the legality of shareholder-adopted bylaws that weaken the antitakeover force of a staggered board by moving the company’s annual meeting up from later parts of the calendar year to January, and (ii) the subsequent decision by the Delaware Supreme Court to overturn the Chancery Court ruling and invalidate such bylaws. We find evidence consistent with the hypothesis that the Chancery Court ruling increased the value of affected companies – namely, companies with a staggered board and an annual meeting in later parts of the calendar year – and that the Supreme Court ruling produced a reduction in the affected companies’ value. The identified effects were most pronounced for firms for which control contests are especially relevant due to relative underperformance, small firm size, high asset pledgibility, or high takeover intensity in their industry. Our findings have implications for the long-standing debate on staggered boards. The findings are consistent with the market’s viewing staggered boards as bringing about a reduction in firm value. Our findings are thus consistent with leading institutional investors’ policies in favor of board de-staggering, and with the view that the ongoing process of board de-staggering in public firms can be expected to enhance shareholder value.

Staggered Boards and the Wealth of Shareholders: Evidence from Two Natural Experiments

While staggered boards have been documented to be negatively correlated with firm valuation, such association might be due to staggered boards either bringing about lower firm value or merely reflecting the tendency of low-value firms to have staggered boards. In this paper, we use two natural experiments to shed light on the causality question. In particular, we focus on two recent court rulings, separated by several weeks, that affected in opposite directions the antitakeover force of staggered boards: (i) a ruling by the Delaware Chancery Court approving the legality of shareholder-adopted bylaws that weaken the antitakeover force of a staggered board by moving the company’s annual meeting up from later parts of the calendar year to January, and (ii) the subsequent decision by the Delaware Supreme Court to overturn the Chancery Court ruling and invalidate such bylaws. We find evidence consistent with the hypothesis that the Chancery Court ruling increased the value of affected companies – namely, companies with a staggered board and an annual meeting in later parts of the calendar year – and that the Supreme Court ruling produced a reduction in the affected companies’ value. The identified effects were most pronounced for firms for which control contests are especially relevant due to relative underperformance, small firm size, high asset pledgibility, or high takeover intensity in their industry. Our findings have implications for the long-standing debate on staggered boards. The findings are consistent with the market’s viewing staggered boards as bringing about a reduction in firm value. Our findings are thus consistent with leading institutional investors’ policies in favor of board de-staggering, and with the view that the ongoing process of board de-staggering in public firms can be expected to enhance shareholder value

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

Flow harmonic coefficients, v n , which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV . The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features

Helium identification with LHCb

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Curvature-bias corrections using a pseudomass method

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass