cssi/SciSciGPT-SciSciNet huggingface dataset:
A Web of Liability: Does New Cyberbullying Legislation Put Public Schools in a Sticky Situation?

Bullying has long been a concern for students, parents, and schools. However, the explosion of communication technology has transformed the nature of bullying, allowing “cyberbullies” to extend their reach far beyond the physical schoolyard. This development creates uncertainty for schools, legislatures, and courts in assessing when and where schools should be permitted to regulate student behavior.The growing number of tragic cyberbullying incidents, as well as national media coverage, has forced legislatures to take action. This has manifested itself in a number of different statutory forms and approaches.The most aggressive legislation appears to impose new duties on school districts, individual schools, and educators to police and prevent cyberbullying. Increased liability will likely accompany these new duties. This could be problematic since courts have been protective of students’ off-campus free speech rights when schools have acted aggressively to combat cyberbullying.This piece argues that the potential for new liability that schools may face, while perhaps appropriate, will put schools in a “lose-lose” situation. Schools that choose to act in accordance with new legislation will undoubtedly face legal challenges by cyberbullies, claiming violations of free speech rights. Schools that hesitate to act may face liability for failing to fulfill their new statutory duties to protect victims of cyberbullying. In order to balance these competing interests, courts should apply existing legal standards more deferentially to allow schools to combat cyberbullying effectively while also respecting the First Amendment.
The Intergenerational Effects of Paternal Migration on Schooling and Work: What Can We Learn from Children's Time Allocations?

This paper explores the short-run effects of a father's U.S. migration on his children's schooling and work outcomes in Mexico. To get around the endogeneity of paternal migration, I use individual fixed effects and instrumental variables estimation (FEIV) where the instrumental variables are based on U.S. city-level employment statistics in two industries popular with Mexican immigrants. Overall, the estimates suggest that in the short-run, children reduce study hours and increase work hours in response to a father's U.S. migration. Decomposing the sample into sex- and age-specific groups suggests that this is mainly driven by the effects of paternal migration on 12–15 year-old boys. These results are consistent with a story in which the immediate aftermath of a father's migration is one of financial hardship that is borne in part by relatively young children.
From a Trickle to a Flood: A Case Study of the Current Index to Legal Periodicals to Examine the Swell of American Law Journals Published in the Last Fifty Years

Using the lists of journals indexed in the Current Index to Legal Periodicals from the last fifty years, this article analyzes the increase in the number of general law reviews, specialized law journals, student-edited journals, and peer-edited and refereed law journals during the last half-century. Data from the Current Index to Legal Periodicals were combined with further data collected from HeinOnline, American Bar Association (ABA) statistics, and U.S. News & World Report statistics. Comparison of these data not only shows a massive increase in the number of law journal titles being published but also suggests a correlation between the number of law journals published by a law school and its student population, length of time that it has been accredited by the ABA, and its U.S. News & World Report ranking. This article also contains a list of all law journals currently indexed by the Current Index to Legal Periodicals including each journal's date of initial publication, in addition to a list of all p...
Putting Per-Capita Income back into Trade Theory

A major role for per-capita income in international trade, as opposed to simply country size, was persuasively advanced by Linder (1961). Yet this crucial element of Linder’s story was abandon by most later trade economists in favor of the analytically-tractable but counter-empirical assumption that all countries share identical and homothetic preferences. This paper collects and unifies a number of disjoint points in the existing literature and builds further on them using simple and tractable alternative preferences. Adding non-homothetic preferences to a traditional models helps explain such diverse phenomenon as growing wage gaps, the mystery of the missing trade, home bias in consumption, and the role of intra-country income distribution, solely from the demand side of general equilibrium. With imperfect competition, we can explain higher markups and higher price levels in higher per-capita income countries, and the puzzle that gravity equations show a positive dependence of trade on per-capita incomes, aggregate income held constant. The effects of growth are quite different depending on whether it is growth in productivity or through neutral factor-endowment growth, and suggestions are made for calibration, estimation, and gravity equations. The final section presents some empirical results that give preliminary but good support to the crucial assumption that produces many of the results just listed: goods with high capital-labor ratios in production are systematically goods with high income elasticities of demand in consumption.
The power of the law: Central Americans’ legality and everyday life in Phoenix, Arizona

This article examines how a multi-pronged legal regime, composed of laws at the federal, state and local levels, shapes the everyday lives of Guatemalans, Hondurans and Salvadorans in Phoenix, Arizona, with special attention to the ambit of the family. On the basis of qualitative fieldwork conducted over a decade in the Phoenix metro area, and moving away from a focus on undocumented statuses per se, the article shifts attention to how changes in the law affect how immigrants live with their families as well as the separations they experience, and how the effects of the law are felt beyond US borders in multiple forms. Following the pivotal role that the law plays in the immigrants’ lives, the article also notes that the immigrants’ hyper awareness of the law makes them cognizant of the power of the law and how it can be used in other areas of life.
The Borders Of E.U. Tax Policy And U.S. Competitiveness

In March of 2011, the European Commission proposed that the member states of the European Union allow corporations to elect a harmonized corporate income tax. A particularly interesting feature of the proposal is that income would be allocated among the member states using a mathematical apportionment formula rather than, as currently is the law, by determining the source of income on a case-by-case basis. The E.C. proposal presents a number of interesting and important issues. One of the most interesting is how the apportionment feature of the proposal would impact business risk taking within the European Union. The European Commission believes that its proposal would provide for more efficient risk taking. This article agrees and goes further to note that, by making the E.U. a more attractive location for investment, the E.C. proposal would put the U.S. at a competitive disadvantage.
Mixed motives in the equilibrium view of joint intention

We develop a theory of joint intention in contexts in which participants have mixed motives that can manifest in all-things-considered reasons to deviate from contributing to the desired project, e.g., contexts with collective action problems. Our theory is based on strategic equilibrium-based reasoning, which links the characterization of joint intention in terms of individual intentions with conditions on strategy profiles of the underlying strategic games. We use elements of equilibrium reasoning to construct a counterfactual account of joint intention in the mixed-motive contexts, which extends the reach of the notion of joint intention considerably beyond that of previous formulations.
Stock Market Forecastability and Volatility: A Statistical Appraisal

This paper presents and implements statistical tests of stock market forecastability and volatility that are immune from the severe statistical problems of earlier tests. It finds that although the null hypothesis of market efficiency is rejected, the rejections are only marginal. The paper also shows how volatility tests and recent regression tests are closely related, and demonstrates that when finite sample biases are taken into account, regression tests also fail to provide strong evidence of violations of the conventional valuation model.
Bait, mask, and ruse: Technology and police deception

Deception and enticement have long been tools of the police, but new technologies have enabled investigative deceit to become more powerful and pervasive. Most of the attention given to today’s advances in police technology tends to focus either on online government surveillance1 or on the use of algorithms for predictive policing or threat assessment.2 No less important but less well known, however, are the enhanced capacities of the police to bait, lure, and dissemble in order to investigate crime. What are these new deceptive capabilities, and what is their importance? Misrepresentation by the police can take many forms. The police may deceive by concealing their identity, their purpose, or both. Police conceal their purpose when they try to convince a suspect to open his door by asking for help in locating a fictitious person. They conceal both their identity and purpose when they pretend to be mobsters or potential robbery victims. Covert policing of this second type has greatly expanded over time; a recent New York Times investigation estimated that there are thousands of undercover agents at the federal level alone.3 Consider the new world of baits, masks, and ruses. Baits: While offering attractive targets to entice potential thieves is not new, the baiting capabilities of the police are. Small GPS trackers can be embedded into everyday items, and their low cost means that police departments can use them to investigate many different crimes. For example, the NYPD has planted “bait bottles” with GPS trackers in drugstores to catch OxyContin thieves.4 Albuquerque police have
Coordination with flexible information acquisition

Abstract We study flexible information acquisition in a coordination game. “Flexible” acquisition means that players choose not only how much but also what kind of information to acquire. Information acquisition has a cost proportional to reduction of entropy. Hence, players will collect the information most relevant to their welfare but can be rationally inattentive to other aspects of the fundamental. When information is cheap, this flexibility enables players to acquire information that makes efficient coordination possible, which also leads to multiple equilibria. This result contrasts with the global game literature, where information structure is less flexible and cheap information leads to a unique equilibrium with inefficient coordination.
Space, Time, Memory: Gendered Recollections of Wartime Los Alamos

In this article, I examine configurations of space and time in memory texts written by men and women who lived at Los Alamos, New Mexico, during World War II. These accounts each use somewhat different parameters to frame their recollections, drawing attention to the gendered hierarchy of space-times involved in the work of the Manhattan Project. Despite their heterogeneous authors and motivations, however, these frameworks circumscribe memories within a narrow time and space—the physical boundaries of the Los Alamos site and the frantic tempo of wartime work. In this way, they construct a collective memory of Los Alamos that overlooks the broader spaces and times within which the development of the atomic bomb was situated. Far from being neutral, like dates on a calendar or coordinates on a map, space and time function ideologically to shape memories in ways that support the ideological interests of scientists.
Fiscal policies in open cities with firms and households

Abstract This paper provides an equilibrium numerical model of an open city economy with mobile firms and resident workers. Given household preferences and firm technologies and an exogenous configuration of city tax rates and national grants and fiscal mandates, the model calculates equilibrium values for aggregate city economic activity, factor prices, and finally, local tax bases, revenues, and public goods provision. The model is calibrated to the Philadelphia economy for Fiscal Year 1998. We then explore the economic and fiscal consequences of raising city tax rates and the city’s ability to finance rising local welfare payments. We find the city to be incapable of bearing significant increases in local responsibility for welfare transfers.
Do Economics Journal Archives Promote Replicable Research

All the long-standing archives at economics journals do not facilitate the re- production of published results. The data-only archives at Journal of Business and Eco- nomic Statistics and Economic Journal fail in part because most authors do not contribute data. Results published in the FRB St. Louis Review can rarely be reproduced using the data+code in the journal archive. Recently created archives at top journals should avoid the mistakes of their predecessors. We categorize reasons for archives' failures and identify successful policies. JEL classification: B40, C80 Est-ce que les archives des revuespromeuvent les travaux de replication? Toutes les archives de longue date des revues ´ economiques ne facilitent pas la r´
Why does IPO volume fluctuate so much

Abstract IPO volume fluctuates substantially over time. This paper compares the extent to which the aggregate capital demands of private firms, the adverse-selection costs of issuing equity, and the level of investor optimism can explain these fluctuations. Empirical tests include both aggregate and industry-level time-series regressions using proxies for the above factors and an analysis of the relation between post-IPO stock returns and IPO volume. Results indicate that firms’ demands for capital and investor sentiment are important determinants of IPO volume, in both statistical and economic terms. Adverse-selection costs are also statistically significant, but their economic effect appears small.
To the Water’s Edge, and Beyond: Effects of Shore Protection Projects on Beach Development

The effects on real estate development of shore-protection efforts that lower erosion rates and storm hazards are both controversial and difficult to detect. A simple theoretical model indicates that shore protection is likely to “tilt” development from areas a few hundred feet inland toward beachfront property. A modified repeat-sale house price index is used to measure price appreciation rates to the water’s edge. We are able to formulate an extremely sensitive empirical test for a tilt in rates of house-price appreciation implied by a tilt in development. Surprisingly, we find no significant evidence that shore-protection efforts have produced additional beachfront development in the Florida counties studied. The method used in this article is quite general and could be used in a number of applications where an environmental effect impacts real estate differentially over space.
How Logo Colors Influence Shoppers’ Judgments of Retailer Ethicality: The Mediating Role of Perceived Eco-Friendliness

Despite the moral gravity and far-reaching consequences of ethical judgment, evidence shows that such judgment is surprisingly malleable, prone to bias, informed by intuition and implicit associations, and swayed by mere circumstance. In this vein, this research examines how mere colors featured in logos can bias consumers’ ethical judgments about a retailer. Exposure to a logo featuring an eco-friendly color makes an ethically ambiguous practice seem more ethical; however, exposure to a logo featuring a non-eco-friendly color makes the same practice seem less ethical (Study 1). This effect is due to the embodied meaning of color, not referential meanings associated with the names of colors, and it is mediated by perceptions of a retailer’s eco-friendliness (Study 2a). Furthermore, although the word “green” appears to influence ethical ratings of retail practices more than the word “blue,” visual exposure to either color evokes similar perceptions of eco-friendliness and influences ethical judgments (Study 2b). Study 2c assesses and rules out alternative explanations for this effect. Critically, an eco-friendly color can skew judgments even when the practices judged are not ethically ambiguous (Study 3). Individual differences in ethical sensitivity moderate the observed effect, such that individuals who are less ethically sensitive are less influenced by color (Study 4). The article concludes with a discussion on how logo colors shape consumers’ perceptions of retailer ethicality.
Modeling and forecasting mortality rates

Abstract We show that by modeling the time series of mortality rate changes rather than mortality rate levels we can better model human mortality. Leveraging on this, we propose a model that expresses log mortality rate changes as an age group dependent linear transformation of a mortality index. The mortality index is modeled as a Normal Inverse Gaussian. We demonstrate, with an exhaustive set of experiments and data sets spanning 11 countries over 100 years, that the proposed model significantly outperforms existing models. We further investigate the ability of multiple principal components, rather than just the first component, to capture differentiating features of different age groups and find that a two component NIG model for log mortality change best fits existing mortality rate data.
Council-Manager Conflict and Cooperation in Times of Fiscal Distress:

the midst of trying times. Revenues have not kept up with the demands for public services. Governments across the country are cutting back services, reducing their operating hours, and in some cases, lay ing off public employees and contracting out their responsibilities. Florida's local governments have been hit especially hard. The decline in the hous ing industry and an increase in property foreclosures have resulted in a significant reduction in property taxes. In Florida, local governments receive most of their rev enues from property taxes. Unlike many oth er states, Florida does not have a state income tax to ensure stable revenue patterns over time. Florida residents are also known for resisting tax increases. When Gov. Charlie Crist was running for office, he promised voters that if elected, he would lower prop erty taxes. During the spring 2007 legisla tive session, the governor and the state leg islature mandated a reduction in the millage rate imposed by local governments. The loss of revenue was exacerbated on
Adaptive consumption behavior

Abstract In this paper we propose and study a theory of adaptive consumption behavior under income uncertainty and liquidity constraints. We assume that consumption is governed by a linear function of wealth, whose coefficients are revised each period by a procedure that places few informational or computational demands on the consumer. We show that under a variety of settings the procedure converges quickly to a set of coefficients with low welfare cost relative to a fully optimal nonlinear consumption function.
Competing for Capital: The Diffusion of Bilateral Investment Treaties, 1960-2000

Over the past forty- five years, bilateral investment treaties (BITs) have become the most important international legal mechanism for the encouragement and governance of foreign direct investment. Their proliferation over the past two decades in particular has been phenomenal. These intergovernmental treaties typically grant extensive rights to foreign investors, including protection of contractual rights and the right to international arbitration in the event of an investment dispute. We argue that the spread of BITs is driven by international competition among potential host countries – typically developing countries – for foreign direct investment. We design and test three different measures of competition. The evidence suggests that potential hosts are more likely to sign BITs when their competitors have done so. We also control for diffusion via coercion, social learning, and cultural networks. We find some evidence that coercion plays a role, but less support for learning or cultural explanations. Our main finding is that diffusion in this case is associated with competitive economic pressures among developing countries to capture a share of foreign investment. We are agnostic at this point about the benefits of this competition for development.
Why Measure Inequality

A large body of literature is devoted to the measurement of income inequality, yet little attention is given to the question, Why measure inequality? However, the reasons for measurement bear importantly on whether and how measurement should be done. Upon examination, normative measures are found to be of questionable value. Descriptive measures, by contrast, may be useful, but the appropriate measure depends on the field of application rather than on general, a priori principles of the sort that are emphasized in the existing measurement literature. Measures of poverty are also considered, and similar conclusions are reached.
An Empirical Analysis of Stock and Bond Market Liquidity

This article explores cross-market liquidity dynamics by estimating a vector autoregressive model for liquidity (bid-ask spread and depth, returns, volatility, and order flow in the stock and Treasury bond markets). Innovations to stock and bond market liquidity and volatility are significantly correlated, implying that common factors drive liquidity and volatility in these markets. Volatility shocks are informative in predicting shifts in liquidity. During crisis periods, monetary expansions are associated with increased liquidity. Moreover, money flows to government bond funds forecast bond market liquidity. The results establish a link between "macro" liquidity, or money flows, and "micro" or transactions liquidity. A number of important theorems in finance rely on the ability of investors to trade any amount of a security without affecting the price. However, there exist several frictions,1 such as trading costs, short sale restrictions, and circuit breakers, that impact price formation. The influence of market imperfections on security pricing has long been recognized. Liquidity, in particular, has attracted a lot of attention from traders, regulators,
The credits that count: how credit growth and financial aid affect college tuition and fees

Using a two-stage least squares model, we build a macroeconomic model of supply and demand for US higher education as measured by enrollment. We find that college education benefits (e.g. relative earnings and employment level), credit factors (e.g. student loan amounts and household debt), and financial aid shift demand. Higher tuition prices increase the appeal of higher education for students but credit constraints put a barrier on demand growth. Tuition prices and debt levels are highly correlated, suggesting that students respond to higher tuition prices by borrowing. School's operating costs as well as tuition and non-tuition revenue drive supply. Schools can use tuition prices to signal quality, and relative demand-side price-in-elasticity allows them to raise prices. For the private institution sector alone, we see a higher level of consumer price sensitivity, with schools determining enrollment levels and adjusting tuition price accordingly.
Two-Sided Network Effects: A Theory of Information Product Design

How can firms profitably give away free products? This paper provides a novel answer and articulates trade-offs in a space of information product design. We introduce a formal model of two-sided network externalities based in textbook economics-a mix of Katz and Shapiro network effects, price discrimination, and product differentiation. Externality-based complements, however, exploit a different mechanism than either tying or lock-in even as they help to explain many recent strategies such as those of firms selling operating systems, Internet browsers, games, music, and video. The model presented here argues for three simple but useful results. First, even in the absence of competition, a firm can rationally invest in a product it intends to give away into perpetuity. Second, we identify distinct markets for content providers and end consumers and show that either can be a candidate for a free good. Third, product coupling across markets can increase consumer welfare even as it increases firm profits. The model also generates testable hypotheses on the size and direction of network effects while offering insights to regulators seeking to apply antitrust law to network markets.
Blockbuster Culture's Next Rise or Fall: The Impact of Recommender Systems on Sales Diversity

This paper examines the effect of recommender systems on the diversity of sales. Two anecdotal views exist about such effects. Some believe recommenders help consumers discover new products and thus increase sales diversity. Others believe recommenders only reinforce the popularity of already-popular products. This paper seeks to reconcile these seemingly incompatible views. We explore the question in two ways. First, modeling recommender systems analytically allows us to explore their path-dependent effects. Second, turning to simulation, we increase the realism of our results by combining choice models with actual implementations of recommender systems. We arrive at three main results. First, some well-known recommenders can lead to a reduction in sales diversity. Because common recommenders (e.g., collaborative filters) recommend products based on sales and ratings, they cannot recommend products with limited historical data, even if they would be rated favorably. In turn, these recommenders can create a rich-get-richer effect for popular products and vice versa for unpopular ones. This bias toward popularity can prevent what may otherwise be better consumer-product matches. That diversity can decrease is surprising to consumers who express that recommendations have helped them discover new products. In line with this, result two shows that it is possible for individual-level diversity to increase but aggregate diversity to decrease. Recommenders can push each person to new products, but they often push users toward the same products. Third, we show how basic design choices affect the outcome, and thus managers can choose recommender designs that are more consistent with their sales goals and consumers' preferences.
Globalization, Macroeconomic Performance, and the Exchange Rates of Emerging Economies

Among the developing countries of the world, those emerging markets that have sought some degree of integration into world finance are characterized by higher per capita incomes, higher long-run growth rates, and lower output and consumption volatility. These characteristics are more likely to be causes than effects of financial integration. The measurable gains from financial integration appear to be lower for emerging markets than for higher-income countries, and appear to have been limited by recent crises. One factor limiting the gains from financial integration is the difficulty emerging economies face in resolving the open-economy trilemma. Given their structural and institutional features, many emerging economies cannot live comfortably either with fixed or with freely floating exchange rates. Most recently, the exchange rates of several emerging countries display attempts at stabilization punctuated by high volatility in periods of market stress.
Disaster Awareness and Level of Compliance to Disaster Programs in a Highly Urbanized City

Disaster is an event that shapes our future. During a disaster, it affects lives, infrastructures, livestock and produce, and we can only adapt to it. The aim of this study is to analyze disaster awareness and level of compliance to disaster programs of selected individuals in a highly urbanized city in Central Luzon, Philippines. The study made use of a descriptive-correlational design. One hundred five (105) individuals took part in the survey using a convenience-sampling technique. This study used an adapted and modified instrument for the survey. For the statistical treatment, the researcher used SPSS 20 in computing the data gathered. Results show that the respondents are aware of disaster but in terms of level of compliance, they answered moderately complied. In addition, there are significant differences in disaster awareness and level of compliance with disaster programs when grouped according to location and the number of family members. Last, there is a relationship between the locations, disaster awareness and compliance level on disaster programs in the study. Based on the results of the study, the researcher recommended pertinent ideas and concepts for improved compliance with disaster programs.
The Presentation Arrangements of Pro Forma Earnings Disclosures: Managerial Incentives and Market Responses

This study examines whether the presentation of pro forma earnings disclosures within earnings announcements reflects managerial incentives, as well as the impact of these presentation decisions on equity market pricing of earnings. Using hand-collected data, I measure “presentation” along two dimensions: emphasis of pro forma earnings within the earnings announcement, and the display format of earnings. Consistent with expectations, I document three empirical regularities. First, these presentation decisions appear to reflect managerial opportunism, such as the desire to beat benchmark earnings. Second, these decisions affect the market reaction to disclosed earnings. Finally, implementation of Regulation G, which mandated improved reconciliation of pro forma earnings to GAAP earnings, reduces both opportunistic presentation as well as the influence of presentation arrangements over investors’ decision making. Overall, the results suggest that presentation of pro forma earnings also reflects managerial incentives and market pricing, and that regulatory efforts to mitigate these effects have been successful.
Using unstructured and qualitative disclosures to explain accruals

Abstract We examine the usefulness of support vector regressions (SVRs) in assessing the content of unstructured, qualitative disclosures by relating MD&A-based SVR-accrual estimates (MD&A accruals) to actual accruals. We find that MD&A accruals explain a statistically and economically significant portion of firm-level accruals and identify more persistent accruals. We find that the explanatory power of MD&A accruals is higher for more readable 10-Ks, thereby providing evidence for the construct validity of the readability measures. To highlight the flexibility of the SVR method, we apply it to other dependent variables and disclosures. We find that MD&A-based cash-flow forecasts produced by SVR predict next period’s cash flows. We apply SVR to conference call transcripts and find accruals estimates have similar explanatory power to MD&A accruals. Finally, the explanatory power of MD&A accruals increases between 1994 and 2013.
Defined benefit pension de‐risking and corporate risk‐taking

U.S. corporate sponsors of defined benefit (DB) pension plans in recent years have been de‐risking by paying premiums to transfer their pension plan assets and liabilities to the balance sheets of third‐party insurers. The passage of the Moving Ahead for Progress in the 21st Century Act (MAP‐21) in 2012 provided the pension funding relief necessary to make de‐risking a mainstream corporate activity. This study provides the first empirical analysis of plan and firm factors that cause a firm to de‐risk its DB pension plans. We find a positive association between de‐risking and aggregate corporate risk taking. The results also show that de‐risking, on average, has a stronger effect on corporate financing policy than investment policy, leading to an increase in credit risk reflected in a firm's credit rating and cost of debt. Also, we present suggestive evidence that the reallocation of pension risk increases firm idiosyncratic risk and excess returns.
Concurrency groups: a new way to look at real-time multiprocessor lock nesting

When designing a real-time multiprocessor locking protocol, the allowance of lock nesting creates complications that can inhibit parallelism. Such protocols are typically designed by focusing on the arbitration of resource requests that should be prohibited from executing concurrently. This paper proposes “concurrency groups,” a new concept that reflects an alternative point of view that focuses instead on requests that can be allowed to execute concurrently. A concurrency group is simply a group of lock requests, determined offline, that can safely execute together. This paper’s main contribution is the CGLP, a new real-time multiprocessor locking protocol that supports lock nesting through the use of concurrency groups. The CGLP is able to reap runtime parallelism benefits that have eluded prior protocols by investing effort offline in the construction of concurrency groups. A schedulability study is presented to quantify these benefits, as well as an approach to determining such groups using an Integer Linear Program (ILP) solver, which we show to be efficient in practice.
Nuclear spin assisted magnetic field angle sensing

Quantum sensing exploits the strong sensitivity of quantum systems to measure small external signals. The nitrogen-vacancy (NV) center in diamond is one of the most promising platforms for real-world quantum sensing applications, predominantly used as a magnetometer. However, its magnetic field sensitivity vanishes when a bias magnetic field acts perpendicular to the NV axis. Here, we introduce a different sensing strategy assisted by the nitrogen nuclear spin that uses the entanglement between the electron and nuclear spins to restore the magnetic field sensitivity. This, in turn, allows us to detect small changes in the magnetic field angle relative to the NV axis. Furthermore, based on the same underlying principle, we show that the NV coupling strength to magnetic noise, and hence its coherence time, exhibits a strong asymmetric angle dependence. This allows us to uncover the directional properties of the local magnetic environment and to realize maximal decoupling from anisotropic noise.
The off-grid catch-22: Effective institutions as a prerequisite for the global deployment of distributed renewable power

Abstract Off-grid electric systems powered by renewable sources are appealing because they could reduce energy poverty in a sustainable manner. Yet their deployment has been uneven across the world. In this article, I argue that the deployment of such technology pre-requires effective institutions. This is because the off-grid power industry faces two problems: governments (who may reverse policies on short notice) and customers (who may fail to pay their bills). More democratic regimes, which tend to uphold the rule of law, can mitigate these risks and facilitate long-term investments. Empirically, I show that countries that are democratic deployed considerably more off-grid renewable energy capacity. An increase in the democratic score by one standard deviation leads to an increase in deployed capacity by 40% (95% CI: [20%, 63%]). Further, I show that this effect operates through supply-side institutions, such as the protection of the rule of law. I find little evidence for a competing interpretation of my main results based on the demand side: democracies do not provide more off-grid power in countries with stronger demand for it. These results suggest that institutions are a prerequisite for a successful growth of the off-grid renewable energy industry and raise concerns over the ability of its technologies to penetrate the most destitute regions.
How Are Bankers Paid

We empirically examine bank CEOs’ compensation. We find that bank CEOs (a) are paid less than their nonfinancial counterparts, an effect driven by the CEOs of small bank; (b) experienced declining compensation during 2007–2009 (the hardest-hit banks cut compensation more) but pay is now 24% higher than precrisis levels; (c) are paid more at larger banks, those with less nonperforming loans, those with a higher proportion of noninterest income, and those with less demand-deposit dependence; and (d) have pay highly sensitive to ROA and ROE, but not stock returns. Tail risk is higher when compensation depends more on short-term measures of performance. (JEL F34, G32, G33, G38, K42)
Rates of gene conversions between Escherichia coli ribosomal operons.

Due to their universal presence and high sequence conservation, ribosomal RNA (rRNA) sequences are used widely in phylogenetics for inferring evolutionary relationships between microbes and in metagenomics for analyzing the composition of microbial communities. Most microbial genomes encode multiple copies of rRNA genes to supply cells with sufficient capacity for protein synthesis. These copies typically undergo concerted evolution that keeps their sequences identical, or nearly so, due to gene conversion, a type of intragenomic recombination that changes one copy of a homologous sequence to exactly match another. Widely varying rates of rRNA gene conversion have previously been estimated by comparative genomics methods and using genetic reporter assays. To more directly measure rates of rRNA intragenomic recombination, we sequenced the seven Escherichia coli rRNA operons in 15 lineages that were evolved for ∼13,750 generations with frequent single-cell bottlenecks that reduce the effects of selection. We identified 38 gene conversion events and estimated an overall rate of intragenomic recombination within the 16S and 23S genes between rRNA copies of 3.6 × 10-4 per genome per generation or 8.6 × 10-6 per rRNA operon per homologous donor operon per generation. This rate varied only slightly from random expectations at different sites within the rRNA genes and between rRNA operons located at different positions in the genome. Our accurate estimate of the rate of rRNA gene conversions fills a gap in our quantitative understanding of how ribosomal sequences and other multicopy elements diversify and homogenize during microbial genome evolution.
Quantum Solvers for Plane-Wave Hamiltonians: Abridging Virtual Spaces Through the Optimization of Pairwise Correlations

For many-body methods such as MCSCF and CASSCF, in which the number of one-electron orbitals is optimized and independent of the basis set used, there are no problems with using plane-wave basis sets. However, for methods currently used in quantum computing such as select configuration interaction (CI) and coupled cluster (CC) methods, it is necessary to have a virtual space that is able to capture a significant amount of electron-electron correlation in the system. The virtual orbitals in a pseudopotential plane-wave Hartree-Fock calculation, because of Coulomb repulsion, are often scattering states that interact very weakly with the filled orbitals. As a result, very little correlation energy is captured from them. The use of virtual spaces derived from the one-electron operators has also been tried, and while some correlations are captured, the amount is quite low. To overcome these limitations, we have been developing new classes of algorithms to define virtual spaces by optimizing orbitals from small pairwise CI Hamiltonians, which we term as correlation optimized virtual orbitals with the abbreviation COVOs. With these procedures, we have been able to derive virtual spaces, containing only a few orbitals, which are able to capture a significant amount of correlation. The focus in this manuscript is on using these derived basis sets to target full CI (FCI) quality results for H2 on near-term quantum computers. However, the initial results for this approach were promising. We were able to obtain good agreement with FCI/cc-pVTZ results for this system with just 4 virtual orbitals, using both FCI and quantum simulations. The quality of the results using COVOs suggests that it may be possible to use them in other many-body approaches, including coupled cluster and Moller-Plesset perturbation theories, and open up the door to many-body calculations for pseudopotential plane-wave basis set methods.
Bayesian inference of network structure from unreliable data

Most empirical studies of complex networks do not return direct, error-free measurements of network structure. Instead, they typically rely on indirect measurements that are often error-prone and unreliable. A fundamental problem in empirical network science is how to make the best possible estimates of network structure given such unreliable data. In this paper we describe a fully Bayesian method for reconstructing networks from observational data in any format, even when the data contain substantial measurement error and when the nature and magnitude of that error is unknown. The method is introduced through pedagogical case studies using real-world example networks, and specifically tailored to allow straightforward, computationally efficient implementation with a minimum of technical input. Computer code implementing the method is publicly available.
An efficient and secure location-based alert protocol using searchable encryption and Huffman codes

Location data are widely used in mobile apps, ranging from location-based recommendations, to social media and navigation. A specific type of interaction is that of location-based alerts, where mobile users subscribe to a service provider (SP) in order to be notified when a certain event occurs nearby. Consider, for instance, the ongoing COVID-19 pandemic, where contact tracing has been singled out as an effective means to control the virus spread. Users wish to be notified if they came in proximity to an infected individual. However, serious privacy concerns arise if the users share their location history with the SP in plaintext. To address privacy, recent work proposed several protocols that can securely implement location-based alerts. The users upload their encrypted locations to the SP, and the evaluation of location predicates is done directly on ciphertexts. When a certain individual is reported as infected, all matching ciphertexts are found (e.g., according to a predicate such as “10 feet proximity to any of the locations visited by the infected patient in the last week”), and the corresponding users notified. However, there are significant performance issues associated with existing protocols. The underlying searchable encryption primitives required to perform the matching on ciphertexts are expensive, and without a proper encoding of locations and search predicates, the performance can degrade a lot. In this paper, we propose a novel method for variable-length location encoding based on Huffman codes. By controlling the length required to represent encrypted locations and the corresponding matching predicates, we are able to significantly speed up performance. We provide a theoretical analysis of the gain achieved by using Huffman codes, and we show through extensive experiments that the improvement compared with fixed-length encoding methods is substantial. © 2021 Copyright held by the owner/author(s).
Bargaining and monopolization: In search of the "boundary of Section 2 Liability" between Aspen and Trinko

Aspen1 has had theoretical importance for antitrust law far out of proportion to the trivial dispute it resolved. It has divided adherents of the Chicago and PostChicago Schools, providing a useful vehicle for considering the proper goals of antitrust. And it has gained still more significance by the Supreme Court's recent characterization of it in Trinko2 as "at or near the outer boundary of § 2 liability."3 The Court's description suggests that antitrust governs a limited domain within a larger economy regulated by a variety of other laws, from the common law standards of property and contract to the much more intrusive requirements of the Telecommunications Act. In this image, Aspen recognized a duty to cooperate that was at the margin of antitrust's reach, while the Trinko plaintiffs sought recognition of a duty beyond it. Both cases involved a monopolist's refusal to deal with a smaller rival. Aspen, however, held that an operator of skiing facilities monopolized by refusing to continue to assist a smaller rival in offering skiers easy access to their combined areas, while Trinko held that a local telephone carrier did not monopolize by failing to provide smaller rival carriers with elements of its network. In evaluating the allegations in Trinko, the Court repeatedly referred to the facts and reasoning of Aspen.
Endgame Design for Europa Lander: Ganymede to Europa Approach

The endgame scenario that was explored in this analysis consisted of the part of the trajectory starting at the last Ganymede flyby and ending at the final Europa approach. The basic design components included computing the phasing for the final Ganymede encounter, computing the required intermediate Europa flybys, determining the required maneuvers to transition between the intermediate resonances, and interfacing with a computed portal prior to the final approach. The JPL optimization software, COSMIC, was used in the ephemeris model to optimize solutions computed in the circular restricted three-body problem and compute bounds on the attainable set of solutions by sweeping various design parameters.
Problem-Complexity Adaptive Model Selection for Stochastic Linear Bandits

We consider the problem of model selection for two popular stochastic linear bandit settings, and propose algorithms that adapts to the unknown problem complexity. In the first setting, we consider the $K$ armed mixture bandits, where the mean reward of arm $i \in [K]$, is $\mu_i+ \langle \alpha_{i,t},\theta^* \rangle $, with $\alpha_{i,t} \in \mathbb{R}^d$ being the known context vector and $\mu_i \in [-1,1]$ and $\theta^*$ are unknown parameters. We define $\|\theta^*\|$ as the problem complexity and consider a sequence of nested hypothesis classes, each positing a different upper bound on $\|\theta^*\|$. Exploiting this, we propose Adaptive Linear Bandit (ALB), a novel phase based algorithm that adapts to the true problem complexity, $\|\theta^*\|$. We show that ALB achieves regret scaling of $O(\|\theta^*\|\sqrt{T})$, where $\|\theta^*\|$ is apriori unknown. As a corollary, when $\theta^*=0$, ALB recovers the minimax regret for the simple bandit algorithm without such knowledge of $\theta^*$. ALB is the first algorithm that uses parameter norm as model section criteria for linear bandits. Prior state of art algorithms \cite{osom} achieve a regret of $O(L\sqrt{T})$, where $L$ is the upper bound on $\|\theta^*\|$, fed as an input to the problem. In the second setting, we consider the standard linear bandit problem (with possibly an infinite number of arms) where the sparsity of $\theta^*$, denoted by $d^* \leq d$, is unknown to the algorithm. Defining $d^*$ as the problem complexity, we show that ALB achieves $O(d^*\sqrt{T})$ regret, matching that of an oracle who knew the true sparsity level. This methodology is then extended to the case of finitely many arms and similar results are proven. This is the first algorithm that achieves such model selection guarantees. We further verify our results via synthetic and real-data experiments.
Information-driven stock price comovement

This paper provides a new empirical strategy for testing models of information choice based on observing which types of information are consumed and incorporated into asset prices. Consistent with the predictions of the information driven comovement hypothesis (Veldkamp 2006), we find that stock price comovement is stronger when investors consume qualitative information about firms whose payoffs covary strongly with many others. Furthermore, as aggregate correlation falls, so does the demand for these high covariance signals. Our findings imply that investor information consumption choices are shaped by a market for information, and that these choices can drive excessive stock price comovement.