cssi/SciSciGPT-SciSciNet huggingface dataset:
Fabry-Perot temperature dependence and surface-mounted optical cavities

Factors that contribute to the temperature dependence of a resonant frequency in a low-expansion optical cavity are discussed, including deformation at the cavity ends due to different coefficients of thermal expansion (CTE) of the spacer, optically-contacted mirror substrate and coating. A model of the temperature dependence is presented that incorporates finite-element-analysis of the cavity ends. A measurement of frequency versus temperature of a cavity mode is used along with the model to deduce a spacer's CTE versus temperature profile. The measured profile correlates very well with a separate experiment utilizing a temporary surface-mounted Fabry-Perot cavity fabricated on the outside of the spacer with hydroxy-catalysis bonding.
TeaForN: Teacher-Forcing with N-grams

Sequence generation models trained with teacher-forcing suffer from issues related to exposure bias and lack of differentiability across timesteps. Our proposed method, Teacher-Forcing with N-grams (TeaForN), addresses both these problems directly, through the use of a stack of N decoders trained to decode along a secondary time axis that allows model-parameter updates based on N prediction steps. TeaForN can be used with a wide class of decoder architectures and requires minimal modifications from a standard teacher-forcing setup. Empirically, we show that TeaForN boosts generation quality on one Machine Translation benchmark, WMT 2014 English-French, and two News Summarization benchmarks, CNN/Dailymail and Gigaword.
Phone-sized whispering-gallery microresonator sensing system

We develop a compact whispering-gallery-mode (WGM) sensing system by integrating multiple components, including a tunable laser, a temperature controller, a function generator, an oscilloscope, a photodiode detector, and a testing computer, into a phone-sized embedded system. We demonstrate a thermal sensing experiment by using this portable system. Such a system successfully eliminates bulky measurement equipment required for characterizing optical resonators and will open up new avenues for practical sensing applications by using ultra-high Q WGM resonators.
The Role of Nuclear Star Clusters in Enhancing Supermassive Black Hole Feeding Rates During Galaxy Mergers

During galaxy mergers the gas falls to the center, triggers star formation, and feeds the rapid growth of supermassive black holes (SMBHs). SMBHs respond to this fueling by supplying energy back to the ambient gas. Numerical studies suggest that this feedback is necessary to explain why the properties of SMBHs and the formation of bulges are closely related. This intimate link between the SMBH’s mass and the large scale dynamics and luminosity of the host has proven to be a difficult issue to tackle with simulations due to the inability to resolve all the relevant length scales simultaneously. In this paper we simulate SMBH growth at high-resolution with FLASH, accounting for the gravitational focusing effects of nuclear star clusters (NSCs), which appear to be ubiquitous in galactic nuclei. In the simulations, the NSC core is resolved by a minimum cell size of about 0.001 pc or approximately 10−3 of the cluster’s radius. We discuss the conditions required for effective gas funneling to occur, which are mainly dominated by a relationship between NSC velocity dispersion and the local sound speed, and provide a sub-grid prescription for the augmentation of central SMBH accretion rates in the presence of NSCs. For the conditions expected to persist in the centers of merging galaxies, the resultant large central gas densities in NSCs should produce drastically enhanced embedded SMBH accretion rates—up to an order of magnitude increase can be achieved for gas properties resembling those in large-scale galaxy merger simulations. This will naturally result in faster black hole growth rates and higher luminosities than predicted by the commonly used Bondi–Hoyle–Lyttleton accretion formalism.
Ultra-wideband Detection of 22 Coherent Radio Bursts on M Dwarfs

Coherent radio bursts detected from M dwarfs have some analogy with solar radio bursts but reach orders of magnitude higher luminosities. These events trace particle acceleration, powered by magnetic reconnection, shock fronts (such as those formed by coronal mass ejections (CMEs)), and magnetospheric currents, in some cases offering the only window into these processes in stellar atmospheres. We conducted a 58 hr ultra-wideband survey for coherent radio bursts on five active M dwarfs. We used the Karl G. Jansky Very Large Array to observe simultaneously in three frequency bands covering a subset of 224–482 MHz and 1–6 GHz, achieving the widest fractional bandwidth to date for any observations of stellar radio bursts. We detected 22 bursts across 13 epochs, providing the first large sample of wideband dynamic spectra of stellar coherent radio bursts. The observed bursts have diverse morphology, with durations ranging from seconds to hours, but all share strong (40%–100%) circular polarization. No events resemble solar Type II bursts (often associated with CMEs), but we cannot rule out the occurrence of radio-quiet stellar CMEs. The hours-long bursts are all polarized in the sense of the x-mode of the star's large-scale magnetic field, suggesting that they are cyclotron maser emission from electrons accelerated in the large-scale field, analogous to auroral processes on ultracool dwarfs. The duty cycle of luminous coherent bursts peaks at 25% at 1–1.4 GHz, declining at lower and higher frequencies, indicating source regions in the low corona. At these frequencies, active M dwarfs should be the most common galactic transient source.
THE IMPACT OF NEUTRINO MAGNETIC MOMENTS ON THE EVOLUTION OF MASSIVE STARS

We explore the sensitivity of massive stars to neutrino magnetic moments. We find that the additional cooling due to the neutrino magnetic moments brings about qualitative changes to the structure and evolution of stars in the mass window 7 M ? M 18 M ?, rather than simply changing the timescales for the burning. We describe some of the consequences of this modified evolution: the shifts in the threshold masses for creating core-collapse supernovae and oxygen-neon-magnesium white dwarfs and the appearance of a new type of supernova in which a partial carbon-oxygen core explodes within a massive star. The resulting sensitivity to the magnetic moment is at the level of (2-4) ? 10?11 ?B.
Bayesian Inference for Polycrystalline Materials

Polycrystalline materials, such as metals, are comprised of heterogeneously oriented crystals. Observed crystal orientations are modelled as a sample from an orientation distribution function (ODF), which determines a variety of material properties and is therefore of great interest to practitioners. Observations consist of quaternions, 4-dimensional unit vectors reflecting both orientation and rotation of a single crystal. Thus, an ODF must account for known crystal symmetries as well as satisfy the unit length constraint. A popular method for estimating ODFs non-parametrically is symmetrized kernel density estimation. However, disadvantages of this approach include difficulty in interpreting results quantitatively, as well as in quantifying uncertainty in the ODF. We propose to use a mixture of symmetric Bingham distributions as a flexible parametric ODF model, inferring the number of mixture components, the mixture weights, and scale and location parameters based on crystal orientation data. Furthermore, our Bayesian approach allows for structured uncertainty quantification of the parameters of interest. We discuss details of the sampling methodology and conclude with analyses of various orientation datasets, interpretations of parameters of interest, and comparison with kernel density estimation methods.
Measuring Female Representation and Impact in Films over Time

Women have always been underrepresented in movies and not until recently has the representation of women in movies improved. To investigate the improvement of female representation and its relationship with a movie’s success, we propose a new measure, the female cast ratio, and compare it to the commonly used Bechdel test result. We employ generalized linear regression with L1 penalty and a Random Forest model to identify the predictors that influence female representation, and evaluate the relationship between female representation and a movie’s success in three aspects: revenue/budget ratio, rating, and popularity. Three important findings in our study have highlighted the difficulties women in the film industry face both upstream and downstream. First, female filmmakers, especially female screenplay writers, are instrumental for movies to have better female representation, but the percentage of female filmmakers has been very low. Second, movies that have the potential to tell insightful stories about women are often provided with lower budgets, and this usually causes the films to in turn receive more criticism. Finally, the demand for better female representation from moviegoers has also not been strong enough to compel the film industry to change, as movies that have poor female representation can still be very popular and successful in the box office.
Probing exotic charged Higgs decays in the Type-II 2HDM through top rich signal at a future 100 TeV pp collider

The exotic decay modes of non-Standard Model Higgs bosons are efficient in probing the hierarchical Two Higgs Doublet Models (2HDM). In particular, the decay mode H± → HW± serves as a powerful channel in searching for charged Higgses. In this paper, we analyze the reach for H± → HW± → $$ t\overline{t}W $$ at a 100 TeV pp collider, and show that it extends the reach of the previously studied ττW final states once above the top threshold. Top tagging technique is used, in combination with a boosted decision tree classifier. At the low tan β region, almost the entire hierarchical Type-II 2HDM parameter space can be probed via the combination of all exotic decay channels.
How hospitalized older adults share concerns during daily rounds.

Abstract Objective To explore how hospitalized older adults’ concerns are solicited and shared during daily rounds. Methods We audio recorded 40 physician-patient conversations during daily rounds in a Veterans Affairs Hospital. We developed codes from the conversation analysis (a qualitative method) for the event sequence analysis (a quantitative method) to calculate the conditional probabilities of physicians soliciting for general concerns leading to patients sharing concerns. We used a mixed-effects Poisson regression to calculate the relationship between number of concerns shared and patient education. Results Most of the 141 concerns were shared during the assessment questions and discussion of the plan of care, such as concerns about the patient’s caregiving responsibilities. The conditional probability was higher when physicians solicited for concerns after the assessment questions (0.56) than during the opening (0.25) or the closing (0.19) of the conversation. The design of the solicitation influenced the probability of patients sharing concerns. The number of concerns shared did not differ by level of education. Conclusion Physicians can provide opportunities for patients to share concerns. Practice implications Soliciting for concerns after the assessment questions, asking “what” concerns a patient may have, and asking about caregiving responsibilities may be useful for patients to share their concerns.
Long-Term Prognosis for Return to Athletic Function after Interspinous Ligament Desmotomy for Treatment of Impinging and Overriding Dorsal Spinous Processes in Horses: 71 Cases (2012–2017)

Objective To determine the long-term return to performance of horses with impinging and/or overriding dorsal spinous processes (ORDSP) treated with interspinous ligament desmotomy (ISLD) and to determine the prognostic value of radiographic and scintigraphic grades. Study design Retrospective study. Animals Seventy-one horses with ORDSP treated with ISLD. Methods Medical records were reviewed for signalment, physical examination, gait evaluation, and number of interspinous spaces treated. Preoperative radiographic and scintigraphic images were evaluated with grading scales. Follow-up was obtained with a telephone questionnaire. Prognostic value of the number of affected interspinous spaces, radiographic grading, and scintigraphic grading was tested by using a χ2 test. Results A median follow-up of 35 months (range, 8-64) was available for 56 horses. Fifty-one of 56 (91.1%) horses returned to some level of performance, with 27 of 51 (52.9%) horses achieving equivalent or higher level of performance. Achieving a lower level of performance was attributed to recurrent back pain in nine of 24 (37.5%) horses and to unassociated lameness in nine of 24 (37.5%) horses. Owners of 44 of 56 (78.6%) horses were satisfied with the postoperative performance level, and owners of 46 of 56 (82.1%) horses would recommend the procedure. None of the variables tested influenced the return to performance. Conclusion Interspinous ligament desmotomy allowed horses with ORDSP to return to some level of performance, although fewer returned to an equivalent or higher level of performance than had previously been reported. Clinical significance Interspinous ligament desmotomy allows affected horses to return to some level of performance, regardless of the severity of radiographic and scintigraphic findings.
HODGE NUMBERS OF LANDAU-GINZBURG MODELS

Abstract We study the Hodge numbers f p , q of Landau–Ginzburg models as defined by Katzarkov, Kontsevich, and Pantev. First we show that these numbers can be computed using ordinary mixed Hodge theory, then we give a concrete recipe for computing these numbers for the Landau–Ginzburg mirrors of Fano threefolds. We finish by proving that for a crepant resolution of a Gorenstein toric Fano threefold X there is a natural LG mirror ( Y , w ) so that h p , q ( X ) = f 3 − q , p ( Y , w ) .
A Game-Theoretic Analysis of the Social Impact of Connected and Automated Vehicles

In this paper, we address the much-anticipated deployment of connected and automated vehicles (CAVs) in society by modeling and analyzing the social-mobility dilemma in a game-theoretic approach. We formulate this dilemma as a normal-form game of players making a binary decision for their mobility and construct an intuitive payoff function inspired by the socially beneficial outcomes of a mobility system consisting of CAVs. We show that the game is equivalent to the Prisoner’s dilemma, which implies that the rational collective decision is the opposite of the socially optimum. We present two different solutions to tackle this phenomenon: one with a preference structure and the other with institutional arrangements. We conclude by showcasing our last result with a numerical study.
Do reservoir computers work best at the edge of chaos

It has been demonstrated that cellular automata had the highest computational capacity at the edge of chaos [N. H. Packard, in Dynamic Patterns in Complex Systems, edited by J. A. S. Kelso, A. J. Mandell, and M. F. Shlesinger (World Scientific, Singapore, 1988), pp. 293–301; C. G. Langton, Physica D 42(1), 12–37 (1990); J. P. Crutchfield and K. Young, in Complexity, Entropy, and the Physics of Information, edited by W. H. Zurek (Addison-Wesley, Redwood City, CA, 1990), pp. 223–269], the parameter at which their behavior transitioned from ordered to chaotic. This same concept has been applied to reservoir computers; a number of researchers have stated that the highest computational capacity for a reservoir computer is at the edge of chaos, although others have suggested that this rule is not universally true. Because many reservoir computers do not show chaotic behavior but merely become unstable, it is felt that a more accurate term for this instability transition is the “edge of stability.” Here, I find two examples where the computational capacity of a reservoir computer decreases as the edge of stability is approached: in one case because generalized synchronization breaks down and in the other case because the reservoir computer is a poor match to the problem being solved. The edge of stability as an optimal operating point for a reservoir computer is not in general true, although it may be true in some cases.
Using excess deaths and testing statistics to improve estimates of COVID-19 mortalities

Factors such as non-uniform definitions of mortality, uncertainty in disease prevalence, and biased sampling complicate the quantification of fatality during an epidemic. Regardless of the employed fatality measure, the infected population and the number of infection-caused deaths need to be consistently estimated for comparing mortality across regions. We combine historical and current mortality data, a statistical testing model, and an SIR epidemic model, to improve estimation of mortality. We find that the average excess death across the entire US is 13$\%$ higher than the number of reported COVID-19 deaths. In some areas, such as New York City, the number of weekly deaths is about eight times higher than in previous years. Other countries such as Peru, Ecuador, Mexico, and Spain exhibit excess deaths significantly higher than their reported COVID-19 deaths. Conversely, we find negligible or negative excess deaths for part and all of 2020 for Denmark, Germany, and Norway.
Towards Safe Locomotion Navigation in Partially Observable Environments with Uneven Terrain

This study proposes an integrated task and motion planning method for dynamic locomotion in partially observable environments with multi-level safety guarantees. This layered planning framework is composed of a high-level symbolic task planner and a low-level phase-space motion planner. A belief abstraction at the task planning level enables belief estimation of dynamic obstacle locations and guarantees navigation safety with collision avoidance. The high-level task planner, i.e., a two-level navigation planner, employs linear temporal logic for a reactive game synthesis between the robot and its environment while incorporating low-level safe keyframe policies into formal task specification design. The synthesized task planner commands a series of locomotion actions including walking step length, step height, and heading angle changes, to the underlying keyframe decision-maker, which further determines the robot center-of-mass apex velocity keyframe. The low-level phase-space planner uses a reduced-order locomotion model to generate non-periodic trajectories meeting balancing safety criteria for straight and steering walking. These criteria are characterized by constraints on locomotion keyframe states, and are used to define keyframe transition policies via viability kernels. Simulation results of a Cassie bipedal robot designed by Agility Robotics demonstrate locomotion maneuvering in a three-dimensional, partially observable environment consisting of dynamic obstacles and uneven terrain.
HARISH-CHANDRA BIMODULES OVER QUANTIZED SYMPLECTIC SINGULARITIES

In this paper we classify the irreducible Harish-Chandra bimodules with full support over filtered quantizations of conical symplectic singularities under the condition that none of the slices to codimension 2 symplectic leaves has type E8. More precisely, consider the quantization 𝒜⋋ with parameter ⋋. We show that the top quotient $$ \overline{\mathrm{HC}}\left(\mathcal{A}\lambda \right) $$ of the category of Harish-Chandra 𝒜⋋-bimodules embeds into the category of representations of the algebraic fundamental group, Γ, of the open leaf. The image coincides with the representations of Γ/Γ⋋, where Γ⋋ is a normal subgroup of Γ that can be recovered from the quantization parameter ⋋ combinatorially. As an application of our results, we describe the Lusztig quotient group in terms of the geometry of the normalization of the orbit closure in almost all cases.
Accelerating convergence to the thermodynamic limit with twist angle selection applied to methods beyond many-body perturbation theory.

We recently developed a scheme to use low-cost calculations to find a single twist angle where the coupled cluster doubles energy of a single calculation matches the twist-averaged coupled cluster doubles energy in a finite unit cell. We used initiator full configuration interaction quantum Monte Carlo as an example of an exact method beyond coupled cluster doubles theory to show that this selected twist angle approach had comparable accuracy in methods beyond coupled cluster. Furthermore, at least for small system sizes, we show that the same twist angle can also be found by comparing the energy directly (at the level of second-order Moller–Plesset theory), suggesting a route toward twist angle selection, which requires minimal modification to existing codes that can perform twist averaging.
The JOBS Act and Information Uncertainty in IPO Firms

ABSTRACT: This study examines the effect of the Jumpstart Our Business Startups Act (JOBS Act) on information uncertainty in IPO firms. The JOBS Act creates a new category of issuer, the Emerging Growth Company (EGC), and exempts EGCs from several disclosures required for non-EGCs. Our findings are consistent with proprietary cost concerns motivating EGCs to eliminate some of the previously mandatory disclosures, which increases information uncertainty in the IPO market, attracts investors who rely more on private information, and leads EGCs to provide additional post-IPO disclosures to mitigate the increased information uncertainty. Our results also are consistent with agency explanations, whereby EGCs exploit the JOBS Act provisions to avoid compensation-related disclosures, which results in larger IPO underpricing for such firms. Overall, we provide evidence on how reduced mandatory disclosure affects the IPO market.
The information content of earnings announcements: new insights from intertemporal and cross-sectional behavior

This study examines the information content of quarterly earnings announcements, measured as the magnitude of stock price revision at earnings announcements relative to price revision at other times. We investigate whether quarterly earnings announcements are informative using a nonparametric approach and 1971–2011 sample period. The findings affirm prior evidence on earlier sample periods that significantly more information is conveyed to investors in the three days around earnings announcements than in randomly chosen three-day periods. Next, we examine the behavior of information content over our sample period and document four key findings. First, there is a dramatic increase in information content at earnings dates from 2001 onward. Second, the market reaction to loss firms is substantially less than that for profitable firms. Third, there is a significantly greater reaction to larger firms. Fourth, reaction at earnings dates is significantly increasing in analyst coverage, and once analyst coverage is controlled, the association with size becomes less significant.
On the Determinants of Foreign Direct Investment to Developing Countries: Is Africa Different?

Abstract This paper explores whether factors that affect Foreign Direct Investment (FDI) in developing countries affect countries in sub-Saharan Africa (SSA) differently. The results indicate that: (a) a higher return on investment and better infrastructure have a positive impact on FDI to non-SSA countries, but have no significant impact on FDI to SSA; (b) openness to trade promotes FDI to SSA and non-SSA countries; however, the marginal benefit from increased openness is less for SSA. These results imply that Africa is different—suggesting that policies that have been successful in other regions may not be equally successful in Africa.
What NSA Is Doing... and Why It's Illegal

On December 16, 2005, The New York Times disclosed the existence of a secret electronic surveillance program being carried out by the National Security Agency (NSA) that involves government interception of the contents of international communications without obtaining warrants. The Foreign Intelligence Surveillance Act of 1978 (FISA), which was enacted following the Supreme Court's decision in United States v. United States District Court (1972) and the Church Committee's disclosure of improper NSA activities, created a comprehensive system regulating electronic surveillance for foreign intelligence purposes. Warrants are required when such surveillance takes place within the United States or when it targets United States persons (citizens or permanent residents) within the United States. FISA warrants are issued by the Foreign Intelligence Surveillance Court (FISC) upon a showing that there is probable cause to believe that the target is a foreign power or the agent of a foreign power. The Bush administration has been very successful so far in withholding from the public the details of the warrantless surveillance program, making a precise assessment of its legality very difficult. However, it appears that the core violation being committed is the targeting of international calls involving United States persons in the United States who appear to have had at least some contact with someone connected to al Qaeda, but where it is uncertain that the FISC would find that there is probable cause to believe that the potential target is an agent of a foreign power. FISA plainly requires a warrant in these situations. The Authorization for the Use of Military Force passed by Congress immediately after 9/11 cannot plausibly be taken to have provided statutory authorization for warrantless interceptions under these circumstances. Moreover, the Administration's claim that it has "inherent constitutional authority" to engage in warrantless surveillance flies in the face of Justice Jackson's concurrence in the Steel Seizure Case. The President's power at its lowest ebb here, because he is acting contrary to FISA.
How Much New Information Is There in Earnings

We quantify the relative importance of earnings announcements in providing new information to the share market, using the R2 in a regression of securities' calendar-year returns on their four quarterly earnings-announcement “window” returns. The R2, which averages approximately 5% to 9%, measures the proportion of total information incorporated in share prices annually that is associated with earnings announcements. We conclude that the average quarterly announcement is associated with approximately 1% to 2% of total annual information, thus providing a modest but not overwhelming amount of incremental information to the market. The results are consistent with the view that the primary economic role of reported earnings is not to provide timely new information to the share market. By inference, that role lies elsewhere, for example, in settling debt and compensation contracts and in disciplining prior information, including more timely managerial disclosures of information originating in the firm's accounting system. The relative informativeness of earnings announcements is a concave function of size. Increased information during earnings-announcement windows in recent years is due only in part to increased concurrent releases of management forecasts. There is no evidence of abnormal information arrival in the weeks surrounding earnings announcements. Substantial information is released in management forecasts and in analyst forecast revisions prior (but not subsequent) to earnings announcements.
The Stock-Bond Return Relation, the Term Structure’s Slope, and Asset-Class Risk Dynamics

We study whether asset-class risk dynamics can help explain the predominantly negative stock-bond return relation and movements in the term structure’s slope over 1997–2011. Using option-derived implied volatilities to measure risk, we find i) the negative stock-bond return relation largely disappears when controlling for risk movements, at both monthly and weekly horizons; ii) the partial relation between equity-risk changes and 10-year T-bond excess returns (term-slope movements) is reliably positive (negative); and iii) a stronger link between equity risk and stock returns implies a more negative stock-bond return correlation. Our results suggest a flight-to-quality influence between equity-risk dynamics and longer-term Treasury pricing.
Is mistrust self-fulfilling?

We study experimentally the effect of expectations on whether trust is repaid. Subjects respond with untrustworthy behavior if they see that little is expected of them. This suggests that guilt aversion plays an important role in the repayment of trust.
Visions and scenarios: Heilbroner's worldly philosophy, Lowe's political economics, and the methodology of ecological economics

Abstract Ecological economics is a transdisciplinary alternative to mainstream environmental economics. Attempts have been made to outline a methodology for ecological economics and it is probably fair to say that, at this point, ecological economics takes a “pluralistic” approach. There are, however, some common methodological themes that run through the ecological economics literature. This paper argues that the works of Adolph Lowe and Robert Heilbroner can inform the development of some of those themes. Both authors were aware of the environmental challenges facing humanity from quite early on in their work and quite ahead of its time. In addition, both Lowe's Economics and Sociology (and related writings) and Heilbroner's “Worldly Philosophy” (itself influenced by this work of Lowe) recognized the endogeneity of the natural environment, the impact of human activity on the environment, and the implications of this for questions of method. Lowe and Heilbroner also became increasingly concerned with issues related to the environment over time, such that these issues became of prime importance in their frameworks. This work deals directly with ecological and environmental issues; both authors also dealt with other issues that relate to the environmental challenge, such as technological change. But it is not only their work that explicitly addresses the environment or relates to environmental challenges that is relevant to the concerns of ecological economists. Heilbroner's Worldly Philosophy and Lowe's Political Economics offer insights that may prove useful in developing a methodology of ecological economics. Ecological economists have taken a pluralistic approach to methodology, but the common themes in this work regarding the importance and nature of vision; analysis (including structural analysis); scenarios; implementation; the necessity of working backwards; the role for imagination; rejecting the positive/normative dichotomy; and so on, all are issues that have been elaborated in Lowe's work, and in ways that are relevant to ecological economics. The goal of the paper is actually quite modest: to make ecological economists aware of the work of the two authors, and get them interested enough to explore the possible contribution of these ideas to their methodological approach.
Efficient estimation of stochastic volatility using noisy observations: a multi-scale approach

With the availability of high-frequency financial data, nonparametric estimation of the volatility of an asset return process becomes feasible. A major problem is how to estimate the volatility consistently and efficiently, when the observed asset returns contain error or noise, for example, in the form of microstructure noise. The issue of consistency has been addressed in the recent literature. However, the resulting estimator is not efficient. In work by Zhang, Myland and Ait-Sahalia, the best estimator converges to the true volatility only at the rate of n-1/6. In this paper, we propose an estimator, the multi-scale realized volatility (MSRV), which converges to the true volatility at the rate of n-1/4, which is the best attainable. We show a central limit theorem for the MSRV estimator, which permits intervals to be set for the true integrated volatility on the basis of the MSRV.
African judges, in their own cause: Reconstituting independent courts in contemporary Africa

The global spread of constitutionalism and judicial review, during the last two decades, has generated vigorous scholarly interest and activity in the comparative study of courts and judicial behavior in transitional democracies. On the vast continent of Africa, South Africa’s postapartheid Constitutional Court, known for its innovative jurisprudence in the area of rights, has emerged as the undisputed favorite of comparative constitutional scholars and social scientists as well as a lodestar for jurists across
From groundnuts to globalization: A structural estimate of trade and growth

Abstract Starting with Romer (1987) and Rivera-Batiz-Romer (1991) economists have been able to model how trade enhances growth through the creation and import of new varieties. In this framework, international trade increases economic output through two channels. First, trade raises productivity levels because producers gain access to new imported varieties. Second, increases in the number of varieties drives down the cost of innovation and results in ever more variety creation. Using highly disaggregate trade data, e.g. Gabon’ s imports of Gambian groundnuts, we structurally estimate the impact that new imports have had in approximately 4000 markets per country. We then move from groundnuts to globalization by building an exact TFP index that aggregates these micro gains to obtain an estimate of trade on productivity growth for each country. We find that in the typical country in the world, new imported varieties account for 10–25% of its productivity growth. However, when we structurally estimate the long-run impacts of these productivity growth effects, we find that import variety growth between 1994 and 2003 raised world permanent income by 17% .
Relative Access to Corrective Speech: A New Test for Requiring Actual Malice

The public figure doctrine has become an anachronism. Current First Amendment protections for defamation1 defendants are centered on a simplistic and antiquated conception of the communications environment— one that would appear quaint were it not so pernicious. This outmoded view of communications media cannot account for the dramatic democratization of the means of mass communication spurred by modern technology. The dissimilarity between the contemporary communications environment and the media landscape that informed the public figure doctrine renders current First Amendment protections insufficient and reveals them as inconsistent with the very rationale that demanded their creation. The basic First Amendment framework for defamation suits announced in Gertz v. Robert Welch, Inc.2 has changed little in the intervening decades.3 The Court’s consideration of defamation—a cause of action inseparably tied to the act of publication4—necessarily implicated its understanding of the means of mass communication. In 1974, “the media” was easily defined. Print publishers and broadcasters exhausted the universe of those capable of communicating to the masses.5 As a result, the
The Case of the Missing Holding: The Misreading of Zafiro v. United States, the Misreplication of Precedent, and the Misfiring of Judicial Process in Federal Jurisprudence on the Doctrine of Mutually Exclusive Defenses

This article traces the origins and evolution of the federal doctrine of mutually exclusive defenses (sometimes also called antagonistic, mutually antagonistic, or irreconcilable defenses) among all the various federal circuits. The doctrine concerns whether criminal co-defendants must be severed and have separate trials if their defenses are sharply conflicting. Through a process of borrowing and paraphrasing dicta from other circuits, a mandatory severance rule for mutually exclusive defenses was assumed into existence without proper holdings or consideration of the issue in most circuits between 1962, when a federal case was decided partly though not entirely on the basis of antagonistic defenses, and the 1980s. Later, in 1993, the United States Supreme Court in Zafiro v. United States specifically declared that there should be no mandatory severance rule for antagonistic defenses, that the inquiry was entirely fact-specific, and that the controlling question was whether a defendant suffered prejudice at trial, but due to linguistic and terminological confusion - particularly varying names for the same thing - various circuits did not get the high court's message. The article is a study in the improper formation and replication of precedent in a common law system, and how normal court processes inadvertently can serve to entrench and conceal flawed precedent.
A Cost‐Effectiveness Analysis of the Grameen Bank of Bangladesh

Reports of the success of the Grameen Bank of Bangladesh have led to rapid growth in funding for microfinance. But has the Grameen Bank been cost-effective? This article compares output with subsidy for the bank in a present-value framework. For the timeframe 1983–97, subsidy per person-year of membership in Grameen was about $20, and subsidy per dollar-year borrowed was about $0.22. Although the article does not measure consumer surplus for Grameen users, the evidence in the literature suggests that surplus probably exceeds subsidy. The Grameen Bank — if not necessarily other microlenders — was probably a worthwhile social investment.
Venture capital and career concerns

Abstract This paper finds evidence that the market for follow-on capital discourages risk taking by venture capital fund managers. The amount of follow-on capital raised by venture capitalists is concave with respect to current fund performance. In addition, managers with less consistent performance are slower, and less likely, to raise a follow-on fund. Venture capitalists adjust their investment strategy to balance fundraising incentives against the incentive to pursue risk provided by carried interest. The findings are consistent with models of career concerns, where an agent's compensation is designed to (partially) offset the implicit incentives created by future employment opportunities.
Constitutional Exchange in Japan: From Shogunate to Parliamentary Democracy

This paper uses some recent work from constitutional political economy to analyze the politics of Japan as it shifted from a medieval empire or federation to a modern parliamentary state in the late nineteenth century. The analysis suggests that the Tokugawa period, the Meiji restoration, and its transition to constitutional monarchy can be understood as settings in which a good deal of constitutional exchange took place. This is not to say that all changes in Japanese history are lawful constitutional reforms or motivated by obvious self-interest, but is to say that constitutional negotiations and self-interest are important determinants of constitutional reform. Even in cases in which military threats are important considerations, resistance to change can be reduced by attempting to find reforms that advance mutual interests and minimize unproductive conflict. The alignment of liberal political and economic interests that produced democracies in many European countries was not quite sufficient to do so in Japan in the 1920s. On the other hand, they clearly produced substantial liberalization of Japanese governance in the half century that followed the Meiji restoration.
Money as a Normative Text

The concept of money is regarded as difficult and complex. Today, lawyers leave the discussion of money to economists. Economists see money as a creation of the law and quietly presuppose its existence, so much so that money has disappeared as a separate entity in micro-economic models of market analysis. This article will show, by discussing briefly the modern double-tier system of money creation and the money multiplication within the fractional reserve banking system, that money is an unusual concept, an example of dematerialised property, created by formalised words, figures and symbols. It seems that writers and poets of the nineteenth and twentieth centuries were probably among the first who were able to realize and describe graphically the 'alchemist' impact of money on society and the representational and commodifying aspects of money. The article will give a few examples of literary works that delve into the concept of money.
Regulatory Trading Restrictions, Overvaluation, and Insider Selling

In 2008, trading restrictions prohibited short selling in nearly 800 U.S. financial stocks with a market value of $1.5 trillion. These measures were quickly adopted abroad and were still being implemented as recently as August 2011. Despite the massive scope, global reach, and continued use of restrictions, outcomes are not well documented or fully understood. This article examines the trading ban and documents four important findings: (1) Trading restrictions stabilized falling prices for most (75%), but not all securities. (2) Price stabilization due solely to TARP is ruled out. (3) Cross-sectional return differences provide further evidence on the relationship between institutional ownership and short sale constraints. Firms with low institutional ownership, low short interest, small market cap, and those traded on the Nasdaq were least affected by the ban. (4) Sharp declines (-40%) in short interest contributed to less informative prices. Overall, results indicate trading restrictions stabilized price but they were less effective for securities previously constrained by other factors. Further, benefits from price stabilizing activities were offset by less informative prices.
DECIPHERING Dun & Bradstreet : DOES THE FIRST AMENDMENT MATTER IN PRIVATE FIGURE-PRIVATE CONCERN DEFAMATION CASES?

In Dun & Bradstreet v. Greenmoss Builders, the Supreme Court of the United States reintroduced a subject matter test into libel law, holding that private figures defamed in the discussion of matters of private concern did not need to prove actual malice to collect punitive or presumed damages. The sweeping language of some of opinions, coupled with the Supreme Court's references to subject matter in subsequent cases, led to confusion over whether and how constitutional protections apply in private plaintiff-private issue cases. This article explores how lower federal and state appellate courts have interpreted Dun & Bradstreet and offers three alternate solutions to appropriately balance the First Amendment rights of defendants with the reputational interests of private plaintiffs in cases arising from the discussion of matters of private concern.
Voluntary disclosures and the exercise of CEO stock options

Abstract We examine voluntary disclosures around the exercise of CEO stock options. Previous research shows that managerial incentives depend on the intended disposition of the exercised options' underlying shares. When CEOs intend to sell the underlying shares of exercised options, they have an incentive to increase stock prices in the pre-exercise period. In contrast, when CEOs intend to hold the underlying shares, they have a tax incentive to decrease stock prices in the pre-exercise period. Consistent with these private incentives, we find a significant increase in the frequency and magnitude of good (bad) news announcements in the pre-exercise period when CEOs implement exercise-and-sell (exercise-and-hold) strategies. We provide some evidence that CEOs' propensities for opportunistic disclosures are positively related to the value of their exercised stock options. Lastly, we find that the Sarbanes–Oxley Act (SOX) generally reduces, but does not eliminate, this type of managerial opportunism.
Political inclusion of marginalized groups: indigenous reservations and gender parity in Bolivia

Focusing on the case of Bolivia, this paper analyzes when and why marginalized groups gain access to political power. The country's experience is puzzling. Though we would have expected the indigenous-led government that came to power in early 2006 to be more receptive to the claims of indigenous movements than to women, the opposite occurred. Indigenous groups received a mere 5% of parliamentary seats and women got a gender parity law. What explains these different results of women's and indigenous demands for political inclusion? Adopting an intersectional approach, we view marginalized groups not as a single category but as a collection of categories. Rather than a premise of politics, group unity is a political achievement. While women overcame divisions between white, urban feminists and indigenous women from popular sectors to lobby for gender parity, the indigenous movement remained divided over reserved seats and the project of indigenous autonomy more generally. Our analysis helps explain why quo...
Job Hopping, Information Technology Spillovers, and Productivity Growth

The movement of information technology IT workers among firms is believed to be an important mechanism by which IT-related innovations diffuse throughout the economy. We use a newly developed source of employee microdata---an online resume database---to model IT workers' mobility patterns. We find that firms derive significant productivity benefits from the IT investments of other firms from which they hire IT labor. Our estimates indicate that over the last two decades, productivity spillovers from the IT investments of other firms transmitted through this channel have contributed 20%--30% as much to productivity growth as firms' own IT investments. Moreover, we find that the productivity benefits of locating near other IT-intensive firms can primarily be explained by the mobility of technical workers within the region. Our results are unique to the flow of IT workers among firms, not other occupations, which rules out some alternative explanations related to the similarity of firms that participate in the same labor flow network. This paper was accepted by Yu Jeffrey Hu, guest department editor, information systems.
Two Theories of Money Reconciled: The Colonial Puzzle Revisited with New Evidence

The purported failure of the classical quantity theory of money in the colonial economy is shown to be a failure of data and not a failure of theory. When new data on the quantity of specie in circulation is added to the current data on paper money and prices, and econometrically estimated in both short- and long-run monetary models, the long-debated anomaly regarding the performance of the classical quantity theory of money in the colonial economy disappears. How paper money was backed and could be exchanged for specie was important, but not in the way theorists assert.
Signal Left, Turn Right Central Rhetoric and Local Reform in China

How have local governments in China been able to break through central policy restrictions in a unitary and authoritarian political system? Why is China’s official discourse in the reform era often...
Economic Consequences of Pegging to the Dollar in a Multicurrency World

The paper studies the monetary mechanism of a three-country world where two large countries are engaged in floating exchange rates with each other, and a small country is pegged to one of these large countries. Three countries possess an endogenous wage determination process, so that the choice of exchange-rate regimes has real consequences. This arrangement creates serious difficulties for the small country. The paper evaluates the relative effectiveness of options for the small country, taking account of endogeneity of wage determination. Complete float of the small country and the currency basket pegging both present promising alternatives, but the complete float is likely to be best.
Crash-Free Sequencing Strategies for Financial Development and Liberalization

This paper uses a stylized model of financial intermediation to characterize the exact circumstances along various paths of economic growth, financial development, and liberalization that can trigger a financial crisis. It shows how to avoid financial crises through proper sequencing of various financial development and liberalization measures. The results of the paper show that naive combinas of financial development and liberalization processes can give rise to financial crises. In some typical situations, in order to avoid a financial crisis, it is important that financial liberalization be accompanied by financial development, in the form of improvements in the financial sector's efficiencies. In the case of fast growing economies, financial development becomes even more imperative.