cssi/SciSciGPT-SciSciNet huggingface dataset:
Reconsidering Racial and Partisan Gerrymandering

In recent years, scholars have come to a general agreement about the relationship between partisan gerrymandering and racial redistricting. Drawing districts that contain a majority of minority voters, as is often required by the Voting Rights Act, is said to help minority voters in those districts but hurt the Democratic Party more broadly. This Article argues that this familiar claim is based on a mistaken assumption about how redistricters can best manipulate districts for partisan gain—an assumption grounded in the idea that all voters can be thought of as either Democrats or Republicans. Relaxing this assumption, and acknowledging that voters come in diverse ideological types, we highlight the fact that the optimal partisan gerrymandering strategy is quite different from the pack-and-crack strategy that is pervasive in the literature. Understanding this optimal strategy leads to a second insight—that the Voting Rights Act constrains Republicans’ partisan ambitions, not Democrats’, as is typically thought. We conclude by discussing some implications for the future of the Voting Rights Act and the next round of decennial redistricting.
Stumbling to Johannesburg: The United States' Haphazard Progress Toward Sustainable Forestry Law

This Article addresses how well forestry law in the United States promotes sustainable development, with special attention to the trends of the past decade. The role of law in shaping forest management decisions has been a contentious issue in this recent period, and forestry has been at the forefront of public concern about sustainability of natural resource management generally. Therefore, the problems and opportunities for forestry law to promote sustainable development are indications of the weaknesses and strengths of the overall U.S. legal regime.
Who Should Be Providing Mortgage Credit to American Households

Who should be providing mortgage credit to American households? Given that the residential mortgage market is a ten-trillion-dollar one, the answer we come up with had better be right, or we may suffer another brutal financial crisis sooner than we would like. Indeed, the stakes are as high as they were in the Great Depression when the foundation of our current system was first laid down. Unfortunately, the housing finance experts of the 1930s seemed to have a greater clarity of purpose when designing their housing finance system. Part of the problem today is that debates over the housing finance system have been muddled by broader ideological battles and entrenched special interests, as well as by plain old inertia and the fear of change. It is worth taking a step back to evaluate the full range of options available to us, as the course we decide upon will shape the housing market for generations to come. This is a Response to Brent Horton, For the Protection of Investors and the Public: Why Fannie Mae’s Mortgage-Backed Securities Should Be Subject to the Disclosure Requirements of the Securities Act of 1933, 89 Tulane L. Rev. __ (forthcoming 2014-2015).
Financial Intermediation as a Beliefs-Bridge Between Optimists and Pessimists

Abstract This paper proposes a new framework for understanding financial intermediation. In contrast to previous research, we consider a setting in which intermediaries possess no inherent information processing or monitoring advantages. Instead, in an economy with overly optimistic entrepreneurs who require funding from pessimistic investors, we show that intermediaries can arise endogenously. In such a setting, only a rational intermediary will be sufficiently optimistic to find it worthwhile to invest in a technology for screening entrepreneurs' projects, and yet be pessimistic enough to use this technology. Our framework produces implications consistent with heretofore unexplained stylized facts, and conjectures which are thus far untested.
The focus of attention in financial reporting

This article discusses a concept of the focus of attention and its implications for financial reporting, a concept that has essentially been ignored in the financial reporting literature. Ignoring it has made dealing with the conflict between the proprietary and the entity theories of the firm the most intractable problem in financial reporting. Exploring the concept of the focus of attention permits abandonment of the conflict rather than continuation of the attempt to solve it. It permits avoiding the errors committed by those involved in the conflict: dealing with the wrong level of abstraction and incorporating contradictions, fictions, and false assumptions. Applying the concept of the focus of attention helps solve a number of issues not solvable by consideration of the theories of the firm.
The Interplay Between Law School Rankings, Reputations, and Resource Allocation: Ways Rankings Mislead

The law school rankings published by US News and World Report have changed and continue to change the law school world, affecting both the demand and supply sides of legal education. Are the rankings valid? Are they changing schools for the better? The US News rankings mislead both applicants and law schools. As measures of educational quality, the US News rankings are seriously flawed. They overweight criteria that matter little, such as bar pass rate. They exclude criteria that matter greatly, such as job satisfaction. At least two of the seemingly valid criteria incorporated into the US News rankings are illusory; the reputation surveys done by US News do not tap into independent professional opinion but instead measure opinions that are echos of US News and, thus, add little reliability to the results that would be reached on other criteria. A more serious problem is the effect of US News rankings on the operation of law schools and students who desire admission. The rankings have created incentives for students who want to be lawyers to go to schools that have grade inflation and take easy courses at those schools. The US News rankings have created incentives for schools to teach to the bar exam, spend money on glossy publications, raise tuition, increase the number of transfer students, and admit students according to their bubble ability (their aptitude for taking multiple-choice standardized exams) rather than their prospects for contributing to the learning environment at the law school or their prospects for becoming effective and responsible lawyers.
Sensitivity of the bank stock returns distribution to changes in the level and volatility of interest rate: A GARCH-M model

Abstract The objective of this paper is to employ the generalized autoregressive conditionally heteroskedastic in the mean (GARCH-M) methodology to investigate the effect of interest rate and its volatility on the bank stock return generation process. This framework discards the restrictive assumptions of linearity, independence, and constant conditional variance in modeling bank stock returns. The model presented here allows for shifts in the volatility equation in response to the changes in monetary policy regime in 1979 and 1982 to be estimated. ARCH, GARCH, and volatility feed back effects are found to be significant. Interest rate and interest rate volatility are found to directly impact the first and the second moments of the bank stock returns distribution, respectively. The latter also affects the risk premia indirectly. The degree of persistence in shocks is substantial for all the three bank portfolios and sensitive to the nature of the bank portfolio and the prevailing monetary policy regime.
Digging deeper into Hardin's pasture: the complex institutional structure of ‘the tragedy of the commons’

A revised application of Ostrom's (Ostrom, 2007) Social-Ecological System (SES) framework to Hardin's ‘tragedy of the commons’ (Hardin, G. (1968), Science, 162(3859): 1243–1248) demonstrates that its institutional structure is more complex than either Hardin or Ostrom had imagined. The ‘tragedy’ arises from several interacting resources and institutions. If the grass on the pasture was not subject to appropriation, the cattle were not privately owned, or property- and contract-enforcement institutions supporting market exchange were absent, then the ‘tragedy of the commons’ would not have arisen regardless of the open-access pasture. This paper highlights the utility of the SES framework and the care required to apply it precisely to specific social-ecological situations.
The Job Search Intensity Supply Curve: How Labor Market Conditions Affect Job Search Effort

During the Great Recession of 2007, unemployment reached nearly 10 percent and the ratio of un- employment to open positions (as measured by the Help Wanted OnLine Index) more than tripled. The weak labor market prompted an unprecedented extension in the length of time in which a claimant can collect unemployment insurance (UI) to 99 weeks, at an expense to date of $226.4 billion. While many claim that extending UI during a recession will reduce search intensity, the effect of weak labor market conditions on search remains a mystery. As a result, policymakers are in the dark as to whether UI ex- tensions reduce already low search effort during recessions or perhaps decrease excessive search, which causes congestion in the labor market. At the same time, modelers of the labor market have little em- pirical justification for their assumptions on how search intensity changes over the business cycle. This paper develops a search model where the impact of macro labor market conditions on a worker's search effort depends on whether these two factors are substitutes or complements in the job search process. Parameter estimates of the structural model using a sample of unemployment spells from the National Longitudinal Survey of Youth 1997 indicate that macro labor market conditions and individual search effort are complements and move together over the business cycle. The estimation also reveals that more risk-averse and less wealthy individuals exhibit less search effort.
Why Voters Veto Vouchers: Public Schools and Community-Specific Social Capital

This article explains voters‘ attachment to public education the public benefit of local schools accrues to adults, not children. Having children in local schools increases parents’ “community-specific social capital.” Through local school connections, parents get to know other adults in their community better, which in turn reduces the transaction costs of citizen provision of local public goods. Vouchers would disperse students from their communities and thereby reduce localized social capital. Empirical evidence supporting this also explains the rise and fall of Robert Putnam’s national indicators of social capital, which have moved in lock-step with the number of children per household.
Deriver's Licenses: An Argument for Establishing a Statutory License for Derivative Works

This paper argues that current law is not properly balancing the interests of copyright holders and the American public to encourage the creation of derivative works. The author advocates a statutory license for the derivative work right based on existing statutory licenses and trademark law. Part I examines the concept of derivative works and their unique value to the progress of American culture. Part II reviews the current state of the law and the creative community, finding both deficiencies and inspiration, with sections on fair use, statutory licenses, the effects of trademark law, psychic effects, and economics. Part III proposes the optimal elements and operation of a statutory license for derivative works.
Short-run money demand

Abstract The conventional wisdom holds that the short-run demand for money is unstable. This paper challenges the conventional view by finding a stable demand for M1 in U.S. data from 1959 through 1993. The approach follows previous work in interpreting long-run money demand as a cointegrating relation, and it uses Goldfeld's partial-adjustment model to interpret short-run dynamics. The key innovation is the choice of the interest rate in the money demand function. Most previous work uses a short-term market rate, but this paper uses the average return on “near monies”—the savings accounts and money market mutual funds that are close substitutes for M1. This choice helps rationalize the behavior of money demand; in particular, the increase in the volatility of velocity after 1980 is explained by increased volatility in the returns on near monies.
The Fantasy of Athlete Publicity Rights: Public Fascination and Fantasy Sports' Assertion of Free Use Place Athlete Publicity Rights on an Uncertain Playing Field

When Hugo Zacchini shot himself out of a cannon, the television station which broadcasted the performer‘s entire fifteen second cannonball performance without permission was held to have violated the performer‘s right to publicity. Despite the station‘s claim that its broadcast was protected as a newsworthy event under the First Amendment, the U.S. Supreme Court ruled that broadcast of the act effectively deprived the performer of the act‘s commercial value and constituted unjust enrichment on behalf of the station by receiving for free what others had paid to view. Baseball players‘ right to publicity in the value of their photograph precluded Topps Chewing Gum, Inc. from including trading cards in its chewing gum packets without compensation and permission of the players. Other athletes have also restricted the commercial use of their name, image, or distinctive references by third parties without authorization. In the sports and entertainment arenas, violations of publicity rights have been adjudged in a number of settings, including the use of the name of a professional hockey player as a character in a comic book, the use of an athlete‘s recognized nickname in a shaving cream commercial, and even a drawing which contained distinctive characteristics resembling a popular athlete.
Non-partisan 'get-out-the-vote' efforts and policy outcomes

Abstract This paper utilizes a simple model of redistributive politics with voter abstention to analyze the impact of nonpartisan ‘get-out-the-vote’ efforts on policy outcomes. Although such efforts are often promoted on the grounds that they provide the social benefit of increasing participation in the electoral process, we find that they have a meaningful impact on policy outcomes and are an important political influence activity for nonprofit advocacy organizations. In equilibrium, nonpartisan gotv efforts are more likely to arise in those segments of the electorate that are sufficiently small and disenfranchised (as measured by the ex ante voter abstention rate). Among those segments in which such efforts arise, the resulting gains are increasing in the level of disenfranchisement of the voters in the segment and decreasing in the segment's size.
The First Amendment and Political Risk

First Amendment doctrine is at its core about the correct response to the fact that speech can increase the risk of social harm. First Amendment risk varies along several dimensions, including distribution of risk, its magnitude, and the magnitude of social benefit. After describing several cases in which the Supreme Court’s assessment risk or harm seems mistaken, I describe the tendency over time for courts to replace doctrine articulated as standards with doctrine articulated as rules with exceptions. I explain why that tendency occurs and can be normatively justified, but that it can produce pathologies when the courts resist, for a variety of reasons, the proliferation of exceptions to the rules. 1. I NTRODUCTION Speech can directly inflict harm, and can increase the risk that harm will occur. False statements about a person’s life can injure that person’s reputation, to the point where the person might lose a job. Speech vigorously criticizing a government policy can increase the risk that some people will take unlawful actions that interfere with the government’s ability to implement that policy. Such speech can increase the likelihood that the government will abandon the policy, and adopt one that promotes social welfare to a lesser extent. First Amendment doctrine is at its core about the correct response to the fact that speech can increase the risk of social harm. Like all risks, First Amendment risk varies along several dimensions, of which I will focus on three. 2 Risk can be distributed broadly or in a more focused way: criticisms of government policy increase the risk that large numbers of people
Performance and Turnover in a Stochastic Partnership

This paper characterizes the social-welfare maximizing equilibrium of a \stochastic partnership matching market", in which players paired to play a stochastic game may quit to be costlessly and anonymously re-matched. Patterns of performance and turnover in this equilibrium are consistent with the well-known \survivorship bias" and, if partners form \meaningful rst impressions", with the \honeymoon eect".
Does PCAOB inspection access improve audit quality? An examination of foreign firms listed in the United States

To gain insight into the impact of the Public Company Accounting Oversight Board’s (PCAOB) auditor inspection program, I examine the association between the PCAOB’s access to inspect auditors of foreign SEC registrants and audit quality. Although the PCAOB is mandated to inspect all auditors of SEC registrants, certain foreign governments prohibit PCAOB inspections of their domestic auditors, providing variation in PCAOB inspection access that is not available when studying a sample of US companies. I find that auditors subject to PCAOB inspection access provide higher quality audits as measured by more going concern opinions, more reported material weaknesses, and less earnings management, relative to auditors not subject to PCAOB inspection access. There is no observable difference between the two sets of auditors prior to the PCAOB inspection regime. The positive effect of PCAOB inspection access on audit quality is observed in jurisdictions with, and without, a local audit regulator. Overall, the results are consistent with PCAOB inspection access being positively associated with audit quality
Corruption and military spending

Abstract Anecdotal evidence relates corruption with high levels of military spending. This paper tests empirically whether such a relationship exists. The empirical analysis is based on data from four different sources for up to 120 countries during 1985–1998. The association between military spending and corruption is investigated by using cross-section and panel regression techniques. The results suggest that corruption is associated with higher military spending as a share of both GDP and total government spending, as well as with arms procurement in relation to GDP and total government spending. The results can be interpreted as evidence that defense spending may be used as a component of an indicator of the quality of governance.
Is Child Labor Harmful? The Impact of Working Earlier in Life on Adult Earnings

AbstractThis paper explores the question: is working as a child harmful to an individual in terms of adult outcomes in earnings? Although this is an extremely important question, little is known about the effect of child labor on adult outcomes. Estimations of an instrumental variables earnings model on data from Brazil show that child labor has a large negative impact on adult earnings for male children even when controlling for schooling and that the negative impact of starting to work as a child reverses at around ages 12–14.
Environmental Compliance Costs and the Distribution of Emissions in the U.S.

Using the properties of the Gini coefficient, a structural model is developed to assess the impact of uniform changes in environmental compliance costs on the distribution of per capita emissions across U.S. counties and states, a distribution that places a larger burden on minorities. Using data from the U.S. EPA’s Toxic Release Inventory and three state-specific measures of environmental compliance costs, we find that uniform increases in federal environmental standards have little impact on the distribution of environmental hazards, and may actually exacerbate spatial inequality. As a result, Federal standards that target specific high pollution locations are necessary to redress current inequities.
The Role of Leasing under Adverse Selection

Leasing contracts are extensively used in durable goods markets. These contracts specify a rental rate and an option price at which the used good can be bought on termination of the lease. This option price cannot be controlled when the car is sold. We show that in a world in which quality is observable, this additional control variable is ineffective. Under adverse selection instead, leasing contracts affect equilibrium allocations in a way that matches observed behavior in the car market. Consistent with the data, our model predicts that leased cars have a higher turnover and that off-lease used cars are of higher quality. Moreover, the model predicts that the recent increase in leasing can be explained by the observed increase in car durability. We show that leasing contracts can improve welfare but that they are imperfect tools. We also show that a producer with market power can benefit from leasing contracts for two reasons: market segmentation and better pricing of the option. Moreover, despite the fact that lessors could structure contracts to prevent adverse selection, we show that this is not in their interest.
Managing Consumer Referrals on a Chain Network

We consider a monopoly that sets a price and differentiated referral fees to spread product information along a simple consumer communication network (a chain). The profit-maximizing solution involves standard monopoly pricing and referral fees that provide consumers with strictly positive referral incentives. Effective price discrimination among consumers based on their positions in the chain occurs both in the case of differentiated referral fees and in the case of uniform referral fees.
Trust, Reciprocity and Rules

In the absence of enforceable contracts, many economic and personal interactions rely on trust and reciprocity. Research shows that although this reliance often works well, sometimes it breaks down. Simple rules mandating minimum standards on reciprocation prevent the most egregious trust violations, but may also undermine behavior that would have otherwise produced higher overall economic welfare. We test the efficacy of exogenously imposed minimum return rules using experimental trust games. We find that rules fail to increase trust and trustworthiness. Thus low minimum standards significantly decrease economic welfare. Although sufficiently restrictive rules restore welfare, trust and trustworthy behavior never returns.
The co‐surface graph and the geometry of hyperbolic free group extensions

We introduce the co-surface graph CS of a finitely generated free group F and use it to study the geometry of hyperbolic group extensions of F. Among other things, we show that the Gromov boundary of the co-surface graph is equivariantly homeomorphic to the space of free arational F-trees and use this to prove that a finitely generated subgroup of Out(F) quasi-isometrically embeds into the co-surface graph if and only if it is purely atoroidal and quasi-isometrically embeds into the free factor complex. This answers a question of I. Kapovich. Our earlier work [S. Dowdall and S. J. Taylor, ‘Hyperbolic extensions of free groups’, to appear in Geom. Topol.] shows that every such group gives rise to a hyperbolic extension of F, and here we prove a converse to this result that characterizes the hyperbolic extensions of F arising in this manner. As an application of our techniques, we additionally obtain a Scott–Swarup type theorem for this class of extensions.
Do banks’ internal Basel risk estimates reflect risk?

Abstract Using supervisory data for U.S. banks, we evaluate the alignment of Basel II/III AIRB (advanced internal ratings based) risk estimates with portfolio risk. We use loan performance as a direct measure of portfolio risk as well as less direct market-based measures. Our results document that AIRB risk weights are highly correlated with loan performance and that, in contrast, Basel I risk weights are not. We find that capital requirements under the AIRB approach are higher than those under Basel I especially for portfolios recently under stress such as mortgages and some sovereign exposures. The alignment of Basel risk estimates with market-based risk indicators is less robust, although the association is nevertheless stronger under the AIRB approach. Our results support the view that internally generated risk weights are determined mostly by portfolio risk and, as a result, are substantially more risk sensitive than the fixed asset class based risk weights of Basel I.
Are Short Sellers Informed? Evidence from the Bond Market

ABSTRACT : We examine whether short sellers in the equity market provide valuable information to investors in the bond market. Using a sample of publicly traded bond data covering the period from 1988 to 2011, we find that firms with high short interest have lower credit ratings and are more likely to have their ratings downgraded. We also find that firms with highly shorted stocks are associated with higher bond yield spreads (about 24 basis points). Evidence of causality from short interest spikes and a natural experiment based on the SEC's Regulation SHO pilot program confirms our findings. Overall, our results suggest that equity short sellers provide predictive information to creditors in the bond market. JEL Classifications: G12; G14. Data Availability: Data are publicly available from the sources identified in the study with the exception of the bond data from Lehman Brothers, which is a proprietary dataset.
International Protection of Persons Undergoing Medical Experimentation: Protecting the Right of Informed Consent

This Article focuses on the right of informed consent to medical experimentation, the "process by which an individual voluntarily expresses his or her willingness to participate in a particular trial, after having been informed of all aspects of the trial that are relevant to the decision to participate." There are many barriers to the comprehension of risk and rational decision-making necessary for informed consent. These barriers are particularly acute in developing nations. The "short course" AZT trials in Africa are a modern example of this problem. In this paradigmatic case, science's quest for a cure has led to the erosion of principles of in-formed consent and the denigration of individual rights. Part II of this Article explains the short course AZT trials conducted on HIV-positive African subjects by U.S. physicians. In particular, Part II outlines violations of the research subject's right of informed consent. Part III describes the experiments of Nazi physicians during World War II, the trial of these physicians at Nuremberg, and the Nuremberg Tribunal's development of the Nuremberg Code, the foundation of modern international regulation of human experimentation. Part IV details the development of international regulation of human experimentation following the Nuremberg Code. Part V highlights the weaknesses of these international regulations insofar as they permitted involuntary medical experimentation with HIV-positive subjects in Africa to continue unabated. Part VI recommends the development of an international solution to guarantee the right of meaningful informed consent to each subject of medical experimentation and proposes the creation of an international convention for the protection of informed consent.
Are Institutions and Empiricism Enough

Legal philosophers have given relatively little attention to international law in comparison to other topics, and philosophers working on international or global justice have not taken international law as a primary focus, either. Allen Buchanan's recent work is arguably the most important exception to these trends. For over a decade he has devoted significant time and philosophical skill to questions central to international law, and has tied these concerns to related issues of global justice more generally. In what follows I review Buchanan's new collection of essays, Human Rights, Legitimacy, and the Use of Force, paying special attention to Buchanan's argument that the philosophy of international law must be more empirically informed than it has been so far, and also to his claim that greater emphasis must be placed on the role of institutions. While these are important claims, I show that Buchanan often does not take the first far enough, and that appealing to institutions cannot do as much as Buchanan hopes or needs if his substantive conclusions are to be correct.
Measuring Deviations from Expected Voting Patterns on Collegial Courts

Even where idiosyncratic factors such as ideology play large and consistent roles in judges' decision making, there are always cases where the patterns of judges' votes confound our expectations. In some ways, these are among the most interesting cases for scholars, raising important questions about judicial behavior and institutions. In the first part of this article, we introduce a quantitative measure of deviations from expected voting patterns intended to allow scholars to systematically study unexpected votes and the questions they raise. In the second part, we illustrate the use of this new measure by developing a preliminary model to predict departures from strict ideological voting in the U.S. Supreme Court in an effort to distinguish alternative explanations for these patterns. Although the conventional wisdom might suggest that disordered voting occurs because of cross-cutting issues, we find little evidence that case complexity is responsible for unexpected coalitions. This result suggests that some alternative explanation exists for such voting behavior; we offer several possibilities—including the influence of legal considerations—in our conclusions.
A Structural Equation Modeling-Based Examination of the Private Label Brand (PLB) Consumer Evaluation Process

The goal of this paper is to answer the question “What variables influence consumer private label brand (PLB) evaluations?” We employ structural equation modeling (SEM) in order to analyze a hypothesized process by which consumer-based evaluations of retailer and product category, along with perceived risk of the category and PLB all affect the ultimate PLB brand evaluation. PLBs have been heavily researched in academic marketing research journals but SEM-based research is minimal. Research has generally been conducted using model-building techniques which are then empirically tested using real-world data. Given the complexity of the process, an alternate approach is to use experimental techniques to gain first-hand PLB data and then analyze it using appropriate methodology. The current project represents a step in that direction. While the model is subject to limitations that call its utility into question, it does provide guidance for a future, more theoretically-sound a priori model and resulting SEM analysis.
A Behavioral Characterization of Plausible Priors

Abstract This Online Appendix contains (i) additional results and discussion related to the notion of plausible priors, and (ii) proofs that have been omitted from the main text in the interest of brevity. In particular, it presents two constructions that deliver a continuum of behaviorally equivalent representations for arbitrary MEU and Bewley preferences.
Market Power, Growth, and Inclusion: The South African Experience

Before the pandemic, the South African economy remained stuck in low gear, with anemic growth, stagnant private investment, and a shrinking tradable sector. Subdued growth has raised unemployment, poverty, and inequality, hindering inclusion efforts. The pandemic has worsened economic and social vulnerabilities. Economic recovery and social inclusion hinge critically on structural reforms to boost competiveness and growth. Product markets represent a cornerstone of the reform strategy. Firms have used their market power to drive up prices and limit competition. Important state-owned monopolies provide low-quality services, while representing a fiscal drag. Existing regulations inhibit the entry of both domestic and foreign firms. Addressing product markets constraints could boost per capita growth by 1 percentage point-adding about 21/2 percentage points to headline growth-and foster greater inclusion.
Learning-based Support Estimation in Sublinear Time

We consider the problem of estimating the number of distinct elements in a large data set (or, equivalently, the support size of the distribution induced by the data set) from a random sample of its elements. The problem occurs in many applications, including biology, genomics, computer systems and linguistics. A line of research spanning the last decade resulted in algorithms that estimate the support up to ±en from a sample of size O(log2⁡(1/e)⋅n/log⁡n), where n is the data set size. Unfortunately, this bound is known to be tight, limiting further improvements to the complexity of this problem. In this paper we consider estimation algorithms augmented with a machine-learning-based predictor that, given any element, returns an estimation of its frequency. We show that if the predictor is correct up to a constant approximation factor, then the sample complexity can be reduced significantly, to log⁡(1/e)⋅n1−Θ(1/log⁡(1/e)). We evaluate the proposed algorithms on a collection of data sets, using the neural-network based estimators from {Hsu et al, ICLR'19} as predictors. Our experiments demonstrate substantial (up to 3x) improvements in the estimation accuracy compared to the state of the art algorithm.
Optimism in Reinforcement Learning with Generalized Linear Function Approximation

We design a new provably efficient algorithm for episodic reinforcement learning with generalized linear function approximation. We analyze the algorithm under a new expressivity assumption that we call ``optimistic closure,'' which is strictly weaker than assumptions from prior analyses for the linear setting. With optimistic closure, we prove that our algorithm enjoys a regret bound of O~(Hd3T) where H is the horizon, d is the dimensionality of the state-action features and T is the number of episodes. This is the first statistically and computationally efficient algorithm for reinforcement learning with generalized linear functions.
Exploring the effects of psychological ownership, gaming motivations, and primary/secondary control on online game addiction

Abstract Online gaming has grown to be a very popular electronic entertainment for people throughout the world. However, the burgeoning popularity of online games in some cases leads to addiction, a phenomenon that has received considerable attention. The purpose of this study is to examine the effects of psychological ownership, gaming motivation, and primary–secondary control on online game addiction (OGA). Based on 436 valid responses collected from online questionnaires, the partial least squares structural equation modeling approach was employed to test the research model. Findings show that the motivations of achievement and escapism are positively associated with psychological ownership toward a virtual gaming environment. Of particular interest is the inverted-U relationship between psychological ownership and OGA, suggesting that too little or too much psychological ownership is associated with less OGA. Finally, individuals with high levels of primary (secondary) control are more (less) inclined to be addicted to online games. This study provides practical implications and strategies to address the alarming increase in OGA. First, families, communities, and universities should encourage outdoor activities, such as sports competitions, and offline cosplay games to address the need for achievement and escapism. Second, individuals who play online games for relaxation should choose a relatively easy or hard mode to avoid game addiction. Finally, parents, teachers, and employers are encouraged to pay attention to individuals who have a high level of primary control since they can be susceptible to OGA. This study provides several theoretical contributions. First, the study enriches OGA and the gaming motivation literature by exploring the roles of gaming motivation, psychological ownership, and personal control strategies as they can be a factor in OGA. In addition, this study is the first to investigate the dark side of psychological ownership in terms of negative outcomes for OGA. This study also advances the personal control strategy literature by understanding the roles of primary and secondary control on OGA.
AFLOW-XtalFinder: a reliable choice to identify crystalline prototypes

The accelerated growth rate of repository entries in crystallographic databases makes it arduous to identify and classify their prototype structures. The open-source AFLOW-XtalFinder package was developed to solve this problem. It symbolically maps structures into standard designations following the AFLOW Prototype Encyclopedia and calculates the internal degrees of freedom consistent with the International Tables for Crystallography. To ensure uniqueness, structures are analyzed and compared via symmetry, local atomic geometries, and crystal mapping techniques, simultaneously grouping them by similarity. The software (i) distinguishes distinct crystal prototypes and atom decorations, (ii) determines equivalent spin configurations, (iii) reveals compounds with similar properties, and (iv) guides the discovery of unexplored materials. The operations are accessible through a Python module ready for workflows, and through command line syntax. All the 4+ million compounds in the AFLOW.org repositories are mapped to their ideal prototype, allowing users to search database entries via symbolic structure-type. Furthermore, 15,000 unique structures — sorted by prevalence — are extracted from the AFLOW-ICSD catalog to serve as future prototypes in the Encyclopedia.
Genetic algorithm based topology optimization of heat exchanger fins used in aerospace applications

Abstract Topology Optimization (TO) in the design of structural components is commonly used and well explored. However, its utilization in the design of complex thermo-fluid equipment used in aerospace applications is limited and relatively new. This is because the coupling between the fluid dynamics, heat transfer, and the shape is complex and nonlinear. Furthermore, the resulting geometry from a TO analysis is often very complex and difficult to manufacture due to the free forms that can occur. With the advent of Additive Manufacturing (AM), however, it has become possible to directly manufacture complex geometries. This study develops a new Genetic Algorithm (GA) based TO combined with Computational Fluid Dynamics (CFD) to produce optimized fin shapes for heat exchangers used in aerospace applications. To implement this approach, a rectangular shaped baseline fin geometry was created using voxel representation. An initial population is generated by mutating the baseline fin a random number of times. The CFD package OpenFOAM is then used to evaluate the performance of each design, after which the optimization algorithm is applied. The GA sorts the designs using a composite fitness function that is comprised of the overall heat transfer and pressure drop, and generates new generations based on mutation and carryover of top performing designs. The study also explores the sensitivity of the GA to the various GA parameters as well as the effect of varying flow Reynolds number. In general, as Reynolds number increases, the percent improvement in the optimum relative to the baseline increases, with potentially an 89% performance improvement. Overall, the approach enables generation of novel freeform designs that may open new performance space for heat transfer applications.
Dynamic Tensor Rematerialization

Checkpointing enables training deep learning models under restricted memory budgets by freeing intermediate activations from memory and recomputing them on demand. Previous checkpointing techniques statically plan these recomputations offline and assume static computation graphs. We demonstrate that a simple online algorithm can achieve comparable performance by introducing Dynamic Tensor Rematerialization (DTR), a greedy online algorithm for checkpointing that is extensible and general, is parameterized by eviction policy, and supports dynamic models. We prove that DTR can train an N-layer linear feedforward network on an Ω(N) memory budget with only O(N) tensor operations. DTR closely matches the performance of optimal static checkpointing in simulated experiments. We incorporate a DTR prototype into PyTorch just by interposing on tensor allocations and operator calls and collecting lightweight metadata on tensors.
Optimal Regularization can Mitigate Double Descent

Recent empirical and theoretical studies have shown that many learning algorithms -- from linear regression to neural networks -- can have test performance that is non-monotonic in quantities such the sample size and model size. This striking phenomenon, often referred to as "double descent", has raised questions of if we need to re-think our current understanding of generalization. In this work, we study whether the double-descent phenomenon can be avoided by using optimal regularization. Theoretically, we prove that for certain linear regression models with isotropic data distribution, optimally-tuned l2 regularization achieves monotonic test performance as we grow either the sample size or the model size. We also demonstrate empirically that optimally-tuned l2 regularization can mitigate double descent for more general models, including neural networks. Our results suggest that it may also be informative to study the test risk scalings of various algorithms in the context of appropriately tuned regularization.
Variational Embedding for Quantum Many-Body Problems

Quantum embedding theories are powerful tools for approximately solving large-scale strongly correlated quantum many-body problems. The main idea of quantum embedding is to glue together a highly accurate quantum theory at the local scale and a less accurate quantum theory at the global scale. We introduce the first quantum embedding theory that is also variational, in that it is guaranteed to provide a one-sided bound for the exact ground-state energy. Our method, which we call the variational embedding method, provides a lower bound for this quantity. The method relaxes the representability conditions for quantum marginals to a set of linear and semidefinite constraints that operate at both local and global scales, resulting in a semidefinite program (SDP) to be solved numerically. The accuracy of the method can be systematically improved. The method is versatile and can be applied, in particular, to quantum many-body problems for both quantum spin systems and fermionic systems, such as those arising from electronic structure calculations. We describe how the proper notion of quantum marginal, sufficiently general to accommodate both of these settings, should be phrased in terms of certain algebras of operators. We also investigate the duality theory for our SDPs, which offers valuable perspective on our method as an embedding theory. As a byproduct of this investigation, we describe a formulation for efficiently implementing the variational embedding method via a partial dualization procedure and the solution of quantum analogs of the Kantorovich problem from optimal transport theory.
The sluggard has no locusts: From persistent pest to irresistible icon

Desert locusts Schistocerca gregaria are threatening the food security of millions of people and devastating economies in eastern Africa and northern India. The ongoing outbreak is the largest in seven decades.These events give us cause to reflect on the natural history of locusts, our fraught relationship with them, and how they are represented in American popular culture and others.Symbolic representations span millennia and most have roots in the natural life cycle of locusts—they transform, they swarm, they devastate specific food crops. There is strong tendency to exaggerate the body size of locusts and the effectiveness of control efforts. Expressions of human futility are rare except in the form of ironic humour.We conclude by suggesting that we humans indulge in hyperbole and humour to normalize and inure ourselves to the psychologically unbearable, and that this tendency is a precondition for the techno‐optimism that drives anti‐locust technologies.There is no substitute for effective monitoring and management programs, but the importance of new and emerging anti‐locust technologies is expected to increase with projections of increased cyclone activity in the northern Indian Ocean.A free Plain Language Summary can be found within the Supporting Information of this article.
Behavior and properties of water in silicate melts under deep mantle conditions.

Water (H2O) as one of the most abundant fluids present in Earth plays crucial role in the generation and transport of magmas in the interior. Though hydrous silicate melts have been studied extensively, the experimental data are confined to relatively low pressures and the computational results are still rare. Moreover, these studies imply large differences in the way water influences the physical properties of silicate magmas, such as density and electrical conductivity. Here, we investigate the equation of state, speciation, and transport properties of water dissolved in Mg1-xFexSiO3 and Mg2(1-x)Fe2xSiO4 melts (for x = 0 and 0.25) as well as in its bulk (pure) fluid state over the entire mantle pressure regime at 2000-4000 K using first-principles molecular dynamics. The simulation results allow us to constrain the partial molar volume of the water component in melts along with the molar volume of pure water. The predicted volume of silicate melt + water solution is negative at low pressures and becomes almost zero above 15 GPa. Consequently, the hydrous component tends to lower the melt density to similar extent over much of the mantle pressure regime irrespective of composition. Our results also show that hydrogen diffuses fast in silicate melts and enhances the melt electrical conductivity in a way that differs from electrical conduction in the bulk water. The speciation of the water component varies considerably from the bulk water structure as well. Water is dissolved in melts mostly as hydroxyls at low pressure and as -O-H-O-, -O-H-O-H- and other extended species with increasing pressure. On the other hand, the pure water behaves as a molecular fluid below 15 GPa, gradually becoming a dissociated fluid with further compression. On the basis of modeled density and conductivity results, we suggest that partial melts containing a few percent of water may be gravitationally trapped both above and below the upper mantle-transition region. Moreover, such hydrous melts can give rise to detectable electrical conductance by means of electromagnetic sounding observations.
Multi-Atlas Image Soft Segmentation via Computation of the Expected Label Value

The use of multiple atlases is common in medical image segmentation. This typically requires deformable registration of the atlases (or the average atlas) to the new image, which is computationally expensive and susceptible to entrapment in local optima. We propose to instead consider the probability of all possible atlas-to-image transformations and compute the expected label value (ELV) , thereby not relying merely on the transformation deemed “optimal” by the registration method. Moreover, we do so without actually performing deformable registration, thus avoiding the associated computational costs. We evaluate our ELV computation approach by applying it to brain, liver, and pancreas segmentation on datasets of magnetic resonance and computed tomography images.