cssi/SciSciGPT-SciSciNet huggingface dataset:
Kitaev's quantum double model as an error correcting code

Kitaev's quantum double models in 2D provide some of the most commonly studied examples of topological quantum order. In particular, the ground space is thought to yield a quantum error-correcting code. We offer an explicit proof that this is the case for arbitrary finite groups. Actually a stronger claim is shown: any two states with zero energy density in some contractible region must have the same reduced state in that region. Alternatively, the local properties of a gauge-invariant state are fully determined by specifying that its holonomies in the region are trivial. We contrast this result with the fact that local properties of gauge-invariant states are not generally determined by specifying all of their non-Abelian fluxes -- that is, the Wilson loops of lattice gauge theory do not form a complete commuting set of observables. We also note that the methods developed by P. Naaijkens (PhD thesis, 2012) under a different context can be adapted to provide another proof of the error correcting property of Kitaev's model. Finally, we compute the topological entanglement entropy in Kitaev's model, and show, contrary to previous claims in the literature, that it does not depend on whether the "log dim R" term is included in the definition of entanglement entropy.
Multi-scale dynamical analysis (MSDA) of sea level records versus PDO, AMO, and NAO indexes

Herein I propose a multi-scale dynamical analysis to facilitate the physical interpretation of tide gauge records. The technique uses graphical diagrams. It is applied to six secular-long tide gauge records representative of the world oceans: Sydney, Pacific coast of Australia; Fremantle, Indian Ocean coast of Australia; New York City, Atlantic coast of USA; Honolulu, US state of Hawaii; San Diego, US state of California; and Venice, Mediterranean Sea, Italy. For comparison, an equivalent analysis is applied to the Pacific Decadal Oscillation (PDO) index and to the Atlantic Multidecadal Oscillation (AMO) index. Finally, a global reconstruction of sea level (Jevrejeva et al. in Geophys Res Lett 35:L08715, 2008) and a reconstruction of the North Atlantic Oscillation (NAO) index (Luterbacher et al. in Geophys Res Lett 26:2745–2748, 1999) are analyzed and compared: both sequences cover about three centuries from 1700 to 2000. The proposed methodology quickly highlights oscillations and teleconnections among the records at the decadal and multidecadal scales. At the secular time scales tide gauge records present relatively small (positive or negative) accelerations, as found in other studies (Houston and Dean in J Coast Res 27:409–417, 2011). On the contrary, from the decadal to the secular scales (up to 110-year intervals) the tide gauge accelerations oscillate significantly from positive to negative values mostly following the PDO, AMO and NAO oscillations. In particular, the influence of a large quasi 60–70 year natural oscillation is clearly demonstrated in these records. The multiscale dynamical evolutions of the rate and of the amplitude of the annual seasonal cycle of the chosen six tide gauge records are also studied.
Multiple Tunable Hyperbolic Resonances in Broadband Infrared Carbon-Nanotube Metamaterials

Aligned densely packed carbon-nanotube metamaterials prepared using vacuum filtration are an emerging infrared nanophotonic material. We report multiple hyperbolic plasmon resonances, together spanning the mid-infrared, in individual resonators made from aligned and densely packed carbon nanotubes. In a near-field scanning optical microscopy (NSOM) imaging study of nanotube metamaterial resonators, we observe distinct deeply subwavelength field profiles at the fundamental and higher-order resonant frequencies. The wafer-scale area of the nanotube metamaterials allows us to combine this near-field imaging with a systematic far-field spectroscopic study of the scaling properties of many resonator arrays. Thorough theoretical modeling agrees with these measurements and identifies the resonances as higher-order Fabry-Perot (FP) resonances of hyperbolic waveguide modes. Nanotube resonator arrays show broadband extinction from 1.5--10 \textmu{}m and reversibly switchable extinction in the 3--5 \textmu{}m atmospheric transparency window through the coexistence of multiple modes in individual ribbons. Broadband carbon-nanotube metamaterials supporting multiple resonant modes are a promising candidate for ultracompact absorbers, tunable thermal emitters, and broadband sensors in the mid-infrared.
A Probability-Density Function Approach to Capture the Stochastic Dynamics of the Nanomagnet and Impact on Circuit Performance

In this paper, we systematically evaluate the variation in the reversal delay of a nanomagnet driven by a longitudinal spin current under the influence of thermal noise. We then use the results to evaluate the performance of an all-spin-logic (ASL) circuit. First, we review and expand on the physics of previously published analytical models on stochastic nanomagnet switching. The limits of previously established models are defined, and it is shown that these models are valid for nanomagnet reversal times <200 ps. Second, the insight obtained from previous models allows us to represent the probability density function (pdf) of the nanomagnet switching delay using the double exponential function of the Frechet distribution. The pdf of a single nanomagnet is extended to more complex nanomagnet circuit configurations. It is shown that the delay-variation penalty incurred by nanomagnets arranged in parallel configuration is dwarfed by the average delay increase for nanomagnets arranged in a series configuration. Finally, we demonstrate the impact of device-level performance variation on the circuit behavior using ASL logic gates. While the analysis presented in this paper uses an ASL-AND gate as the prototype switching circuit in the spin domain, the physical concepts are generic and can be extended to any complex spin-based circuit.
Against the wind: Radio light curves of type ia supernovae interacting with low-density circumstellar shells

For decades a wide variety of observations spanning the radio through optical and on to the X-ray have attempted to uncover signs of type Ia supernovae (SNe Ia) interacting with a circumstellar medium (CSM). The goal of these studies is to constrain the nature of the hypothesized SN Ia mass-donor companion. A continuous CSM is typically assumed when interpreting observations of interaction. However, while such models have been successfully applied to core-collapse SNe, the assumption of continuity may not be accurate for SNe Ia, because shells of CSM could be formed by pre-supernova eruptions (novae). In this work, we model the interaction of SNe with a spherical, low-density, finite-extent CSM and create a suite of synthetic radio synchrotron light curves. We find that CSM shells produce sharply peaked light curves. We also identify a fiducial set of models that obey a common evolution and can be used to generate radio light curves for an interaction with an arbitrary shell. The relations obeyed by the fiducial models can be used to deduce CSM properties from radio observations; we demonstrate this by applying them to the nondetections of SN 2011fe and SN 2014J. Finally, we explore a multiple shell CSM configuration and describe its more complicated dynamics and the resultant radio light curves.
Algorithms for the explicit computation of Penrose diagrams

An algorithm is given for explicitly computing Penrose diagrams for spacetimes of the form $ds^2 = -f(r)\, dt^2 + f(r)^{-1} \, dr^2 + r^2 \, d\Omega^2$. The resulting diagram coordinates are shown to extend the metric continuously and nondegenerately across an arbitrary number of horizons. The method is extended to include piecewise approximations to dynamically evolving spacetimes using a standard hypersurface junction procedure. Examples generated by an implementation of the algorithm are shown for standard and new cases. In the appendix, this algorithm is compared to existing methods.
Connected Heegaard Floer homology of sums of Seifert fibrations

We compute the connected Heegaard Floer homology (defined by Hendricks, Hom, and Lidman) for a large class of 3-manifolds, including all linear combinations of Seifert fibered homology spheres. We show that for such manifolds, the connected Floer homology completely determines the local equivalence class of the associated $\iota$-complex. Some identities relating the rank of the connected Floer homology to the Rokhlin invariant and the Neumann-Siebenmann invariant are also derived. Our computations are based on combinatorial models inspired by the work of Nemethi on lattice homology.
The Role of Symmetry in Mathematics

Over the past few decades the notion of symmetry has played a major role in physics and in the philosophy of physics. Philosophers have used symmetry to discuss the ontology and seeming objectivity of the laws of physics. We introduce several notions of symmetry in mathematics and explain how they can also be used in resolving different problems in the philosophy of mathematics. We use symmetry to discuss the objectivity of mathematics, the role of mathematical objects, the unreasonable effectiveness of mathematics and the relationship of mathematics to physics.
Parallel HOP: A Scalable Halo Finder for Massive Cosmological Data Sets

Modern N-body cosmological simulations contain billions (10{sup 9}) of dark matter particles. These simulations require hundreds to thousands of gigabytes of memory and employ hundreds to tens of thousands of processing cores on many compute nodes. In order to study the distribution of dark matter in a cosmological simulation, the dark matter halos must be identified using a halo finder, which establishes the halo membership of every particle in the simulation. The resources required for halo finding are similar to the requirements for the simulation itself. In particular, simulations have become too extensive to use commonly employed halo finders, such that the computational requirements to identify halos must now be spread across multiple nodes and cores. Here, we present a scalable-parallel halo finding method called Parallel HOP for large-scale cosmological simulation data. Based on the halo finder HOP, it utilizes message passing interface and domain decomposition to distribute the halo finding workload across multiple compute nodes, enabling analysis of much larger data sets than is possible with the strictly serial or previous parallel implementations of HOP. We provide a reference implementation of this method as a part of the toolkit {sup yt}, an analysis toolkit for adaptive mesh refinement datamore » that include complementary analysis modules. Additionally, we discuss a suite of benchmarks that demonstrate that this method scales well up to several hundred tasks and data sets in excess of 2000{sup 3} particles. The Parallel HOP method and our implementation can be readily applied to any kind of N-body simulation data and is therefore widely applicable.« less
Fast and Scalable Complex Network Descriptor Using PageRank and Persistent Homology

The PageRank of a graph is a scalar function defined on the node set of the graph which encodes nodes centrality information of the graph. In this article we use the PageRank function along with persistent homology to obtain a scalable graph descriptor and utilize it to compare the similarities between graphs. For a given graph G(V, E), our descriptor can be computed in O(|E|α(|V|)), where $a$ is the inverse Ackermann function which makes it scalable and computable on massive graphs. We show the effectiveness of our method by utilizing it on multiple shape mesh datasets.
Distributed Resource Management in Systems of Systems: An Architecture Perspective

This paper introduces a framework for studying the interactions of autonomous system components and the design of the connectivity structure in Systems of Systems SoSs. This framework, which uses complex network models, is also used to study the connectivity structure's impact on resource management. We discuss resource sharing as a mechanism that adds a level of flexibility to distributed systems and describe the connectivity structures that enhance components' access to the resources available within the system. The framework introduced in this paper explicitly incorporates costs of connection and the benefits that are received by direct and indirect access to resources and provides measures of the optimality of connectivity structures. We discuss central and a distributed schemes that, respectively, represent systems in which a central planner determines the connectivity structure and systems in which distributed components are allowed to add and sever connections to improve their own resource access. Furthermore, we identify optimal connectivity structures for systems with various heterogeneity conditions.
Biomineralization of hypersaline produced water using microbially induced calcite precipitation.

Abstract Reusing produced water (PW) as the subsequent hydraulic fracturing fluid is currently the most economical and dominant practice in the shale oil and gas industry. However, high Ca2+ present in PW needs to be removed prior to reuse to minimize the potential for well clogging and formation damage. In this study, the microbially induced calcite precipitation (MICP), as an emerging biomineralization technique mediated by ureolytic bacteria, was employed to remove Ca2+ and toxic contaminants from hypersaline PW for the first time. Batch and continuous studies demonstrated the feasibility of MICP for Ca2+ removal from hypersaline PW under low urea and nutrient conditions. Throughout the continuous biofiltration operation with biochar as the media, high removal efficiencies of Ca2+ (~96%), organic contaminants (~100%), and heavy metals (~100% for As, Cd, Mn and Ni, 92.2% for Ba, 94.2% for Sr) were achieved when PW co-treated with synthetic domestic wastewater (SDW) under the condition of PW:SDW = 1:1 & urea 4 g/L. Metagenomic sequencing analysis showed that a stable ureolytic bacterial consortium (containing Sporosarcina and Arthrobacter at the genus level) was constructed in the continuous biofiltration system under hypersaline conditions, which may play a crucial role during the biomineralization process. Moreover, the combination of the MICP and ammonium recovery could significantly reduce the acute toxicity of PW towards Vibrio fischeri by 72%. This research provides a novel insight into the biomineralization of Ca2+ and heavy metals from hypersaline PW through the MICP technique. Considering the low cost and excellent treatment performance, the proposed process has the potential to be used for both hydraulic fracturing reuse and desalination pretreatment on a large scale.
Effect of Solvent Quality on the Phase Behavior of Polyelectrolyte Complexes

The role of polyelectrolyte–solvent interactions, among other non-Coulomb interactions, in dictating the thermodynamics and kinetics of polyelectrolyte complexation is prominent yet sparingly studi...
Domain Adaptive Transfer Learning on Visual Attention Aware Data Augmentation for Fine-grained Visual Categorization

Fine-Grained Visual Categorization (FGVC) is a challenging topic in computer vision. It is a problem characterized by large intra-class differences and subtle inter-class differences. In this paper, we tackle this problem in a weakly supervised manner, where neural network models are getting fed with additional data using a data augmentation technique through a visual attention mechanism. We perform domain adaptive knowledge transfer via fine-tuning on our base network model. We perform our experiment on six challenging and commonly used FGVC datasets, and we show competitive improvement on accuracies by using attention-aware data augmentation techniques with features derived from deep learning model InceptionV3, pre-trained on large scale datasets. Our method outperforms competitor methods on multiple FGVC datasets and showed competitive results on other datasets. Experimental studies show that transfer learning from large scale datasets can be utilized effectively with visual attention based data augmentation, which can obtain state-of-the-art results on several FGVC datasets. We present a comprehensive analysis of our experiments. Our method achieves state-of-the-art results in multiple fine-grained classification datasets including challenging CUB200-2011 bird, Flowers-102, and FGVC-Aircrafts datasets.
The Frankenstein Controversy: The Constitutionality of a Federal Ban on Cloning

Part I of this Article begins with a description of the science of cloning and concludes with a history of cloning research, both of which provide a much needed perspective on the current national debate over cloning. Part II summarizes the President's proposed cloning legislation, as well as the bills introduced in Congress since February of 1997, when Dolly's birth was announced. The quality of the drafting of these proposals suggests caution, because poorly crafted legislation leads to unintended consequences. Part III examines the federal response to cloning in the context of Supreme Court Commerce Clause jurisprudence. Part III concludes that Congress may ban cloning pursuant to its power to regulate interstate commerce, notwithstanding the Supreme Court's recent decision in United States v. Lopez. Finally, Part IV provides an analysis of the Supreme Court's substantive due process cases involving the right of personal privacy. The trends in the Court's case law strongly suggest that a majority of the current Court would hold that a federal government ban on cloning would not violate the Fifth Amendment's Due Process Clause. Although the reasoning used by individual Justices may vary, it is likely that a majority of the current Court would conclude that the right to use and have access to cloning technology is not a fundamental right protected by the Constitution.
Aid Does Matter, After All: Revisiting the Relationship Between Aid and Growth

Recent influential studies among development economists claim that aid to developing countries is not nearly as beneficial to recipient nations as had been expected. Are these statistical analyses right? One problem is that total aid, on which most studies are based, includes two distinct kinds of aid. The first is what we might call "developmental" aid, and the second, geopolitical aid. When the authors focus only on the first kind of aid, they find strong correlations between the level of such aid and average economic growth experienced over the long term. Moreover, they do not find that aid is more effective under specific policy conditions.
Regulating the Sharing Economy: New and Old Insights into an Oversight Regime for the Peer-to-Peer Economy

The significant expansion of new, peer-to-peer businesses, supercharged by the internet and mobile technologies, has led to an exploration of the proper role that government regulation and oversight should play in these new ventures and markets. The value these companies bring in terms of convenience, quality, and competition justify an approach to regulation that promotes innovation but recognizes the need for consumer protection within these markets. As within this so-called “Sharing Economy,” where companies, regulators, and consumers grapple with the question of how to strike the right balance between innovation and consumer protection, there is an industry that shares many features with Sharing Economy models, one that has dealt with many of these same questions for centuries. That industry is the legal profession, and the manner in which it, and the regulatory infrastructure that has evolved as that sector has evolved, offers lessons to those who wish to explore the best way to regulate the Sharing Economy. Because the legal profession shares so many features with the Sharing Economy and has wrestled with many of the same questions with which actors inside and outside the Sharing Economy now struggle, one can glean insights from the lessons learned over the centuries of the development of the rules and protections that govern the functioning of the legal profession to help inform the debate over the need for and contours of any coming regulatory oversight of the Sharing Economy. Moreover, as the manner in which the legal profession has been regulated over the last two centuries exhibits many of the hallmarks of New Governance approaches to regulation, one can also consider New Governance models in any approach to regulation of the Sharing Economy. This Article thus attempts to engage in an analysis of the evolution of regulation of the legal profession in the United States to unearth lessons from that evolution and draw insights from it that might inform approaches to regulating the Sharing Economy and help strike the balance between innovation and consumer protection. These prescriptions consciously borrow from New Governance models to suggest an approach to regulation of the Sharing Economy that will encourage experimentation and innovation, while not jeopardizing consumer safety.
Optimal stopping for non-linear expectations—Part II ✩

Relying on the stochastic analysis tools developed in Bayraktar and Yao (2011) [1], we solve the optimal stopping problems for non-linear expectations.
On the Informed Seller Problem: Optimal Information Disclosure

We consider a revenue-maximizing seller who, before proposing a mechanism to sell her object(s), observes a vector of signals correlated with buyers’ valuations. Each buyer knows only the signal that the seller observes about him, but not the signals she observes about other buyers. The seller first chooses how to disclose her information and then chooses a revenue-maximizing mechanism. We allow for very general disclosure policies, that can be random, public, private, or any mixture of these possibilities. Through the disclosure of information privately, the seller can create correlation in buyers’ private information, which then consist of valuations plus beliefs. For the standard independent private values model, we show that information revelation is irrelevant: irrespective of the disclosure policy an optimal mechanism for this informed seller generates expected revenue that is equal to her maximal revenue under full information disclosure. For more general allocation environments that allow also for interdependent, for common values, and for multiple items, disclosure policies may matter, and the best the seller can do is to disclose no information at all.
Product Market Power and Tax Avoidance: Market Leaders, Mimicking Strategies, and Stock Returns

ABSTRACT: Product market power provides firms with comparative advantages through more persistent profitability and insulation from competitive threats. These advantages likely provide firms with the ability to engage in greater tax avoidance. We present evidence consistent with this hypothesis. We also show that firms mimic the tax outcomes of their product market leaders. Among firms with greater product market power and comparatively high cash tax avoidance, we find stock prices to be less informative and that investors require additional compensation for the risks associated with comparatively high cash tax avoidance. Our results survive numerous robustness tests. Overall, our results suggest that industry dynamics, particularly related to a firm's competitive position, play a meaningful role in corporate tax policy.
Congressional Budget Reform: Impact on the Appropriations Committees

The congressional budget process has undergone several major reforms in the last twenty years: the Congressional Budget and Impoundment Control Act of 1974, the Balanced Budget and Emergency Deficit Control Act of 1985 and 1987 (Gramm-Rudman-Hollings I and II) and the Budget Enforcement Act of 1990 (BEA) that have had a direct impact on the Appropriations Committees and the appropriations process. This article evaluates that impact on the decision-making capacity and power of the Appropriations Committees.
Elite Defection under Autocracy: Evidence from Russia

Elite cohesion is a fundamental pillar of authoritarian stability. High-level defections can signal weakness, embolden the opposition, and sometimes, lead to regime collapse. Using a dataset of 4,291 ruling party candidates in Russia, this paper develops and tests hypotheses about the integrity of elite coalitions under autocracy. Our theory predicts that ruling elites defect when there is greater uncertainty about the regime’s willingness to provide spoils. Regimes that share power with the opposition, limit access to spoils, and lack formal institutions see more defections. Co-opting the opposition assuages outside threats but leaves regime insiders disgruntled and prone to defection. Those with personal followings and business connections are the most likely to defect, since they can pursue their political goals independently of the regime. Taken together, our results highlight important tradeoffs among authoritarian survival strategies. Many of the steps autocrats take to repel challenges simultaneously heighten the risk of defections.
Lender Characteristics and the Neurological Reasons for Strategic Mortgage Default

In this study, we use functional magnetic resonance imaging (fMRI) to understand how homeowners process non-financial information when considering strategic mortgage default. We find that borrowers initially attempt to inhibit their knee-jerk reaction to retaliate against a lender who has engaged in egregious lending practices when compared to a financially conservative lender. Moreover, when defaults are rare, borrowers are less likely to default because violating the social norm results in feelings of disgust. Finally, when a lender refuses a loan modification, the borrower is found to seek retribution. Interestingly, granting even a modest loan modification removes the desire of homeowners to seek retribution towards their lender no matter what their impression of the lender may be. The results carry a number of policy implications.
The optimal sequence of prices and auctions

Abstract To sell a good before a deadline, a monopolist chooses between posting a price and running a costly reserve-price auction each period. Buyers with independent private values arrive over time. For a wide range of auction costs, the profit-maximizing mechanism sequence is to post prices first and then to run auctions. The optimality of the prices-then-auctions mechanism sequence provides a new justification for the hybrid sales mechanism of allowing the “Buy It Now” option before a standard auction on eBay.
Dangerous Diagnoses, Risky Assumptions, and the Failed Experiment of "Sexually Violent Predator" Commitment

Follow this and additional works at: http://digitalcommons.mainelaw.maine.edu/facultypublications Part of the Civil Law Commons, Civil Procedure Commons, Civil Rights and Discrimination Commons, Criminal Law Commons, Evidence Commons, Health Law and Policy Commons, Human Rights Law Commons, Law and Philosophy Commons, Law and Politics Commons, Law and Psychology Commons, Law and Society Commons, Legal Ethics and Professional Responsibility Commons, and the Medical Jurisprudence Commons
Mobile Targeting Using Customer Trajectory Patterns

Rapid improvements in the precision of mobile technologies now make it possible for advertisers to go beyond real-time static location and contextual information on consumers. In this paper we prop...
Reconceiving Reparations: Multiple Strategies in the Reparations Debate

Much of the current debate oyer Mrican-American reparations is characterized by a posture of confrontation and demand, and is exemplified in the law by seeking redress using the doctrines of tort and unjust enrichment. This confrontational posture presents a variety of legal, political. and ethical problems for reparations advocates, and has alienated potential allies from the reparations moyement. This Article examines and exposes the confrontation model's shortcomings, proposing as an alternative a "conversational" model for reparations debate and advocacy. The conversational framework is not only a superior litigation strategy that more closely approximates traditional civil rights litigation, it also embraces the complexity of the current debate on race, premitting the nation to engage in a more inclusive discussion of the future of race in America. {Njothing is more freighted with meaning for our OWlI destiny than the revolution of the Negro A.lIlerican. III far too many ways Amelican Negroes have been G1lOtlw' nation: de/lrived of freedom, crip/lled by hatred, the doors of opportunity closed to hope. In our time change has come to this Nation, too. The Amelican Negro, acting with impressive restraint, has peacefully protested and marched, entered the courtrooms and the scats of goVel'll/llellt, demanding a justice that has long been denied. The voice of the Negro was the call to action. But it is a tribute to A.lIlcnca that, once aroused, the courts and the Congress, the President and 11I0st of the people, have been the allies of progress. 1
Implicit guarantees, business models and banks’ risk-taking through the crisis: Global and European perspectives

Abstract The objectives of this paper are, first, to analyze whether banks’ risk-taking can be explained by factors contributing to implicit guarantees and by factors associated with banks’ business models. Second, it analyzes how risk-taking associated with these factors has changed from a period before the financial crisis (2004–2006), through the crisis (2007–2009), to a period after the crisis (2010–2012). Third, it analyzes whether risk-taking behavior of banks in Europe differs from banks’ risk-taking behavior in the US and globally. The empirical analysis covers 753 banks in a global sample of 45 countries including 86 European banks in 19 countries. Implicit insurance of banks’ creditors is captured both by an expected U-shaped relationship between explicit deposit insurance coverage and banks’ risk-taking, and by factors influencing the likelihood of bail-outs of individual banks. The main business model factors capture banks’ reliance on wholesale funding and their involvement in derivatives markets. A comparison of the results of the cross-section analysis for each sub-period shows that the sources of implicit guarantees have become more pervasive in Europe as well as globally after the crisis. Business models are strongly associated with risk during and after the crisis globally. In Europe, banks relying on wholesale funding as well as those with large derivatives positions are relatively risky. Policy implications of these results are discussed.
Developing an e-Curriculum: Reflections on the Future of Legal Education and on the Importance of Digital Expertise

Legal practice and legal education are both at challenging inflection points, where much of how and what we do as lawyers and how and what we have taught as legal educators comes under scrutiny. Legal technology is an important factor in driving the challenges we face. As we reform our curriculums in this moment of change, we should be guided by considerations of value added, values added, and economic sustainability. Law and technology is an area that is ripe for expansion in our teaching, with the possibility of satisfying all of these criteria. It also provides ample room for scholarly examination. Creating opportunities for learning how technology is shaping legal practice should be a priority for any school looking to provide a useful education for the lawyers of the present, let alone the future.
Scale Factor, R2, and the Choice of Levels versus Returns Models:

This paper analyzes a potential scale effect on the regression R2 to determine if a scale factor can reconcile the arguments concerning the choice between the price levels model and the returns model. Analytically, it is shown that the scale effect depends on the unknown scale-free economic relation and is generally unpredictable. This makes it difficult to choose one model over the other on the basis of controlling for a scale problem. Empirically, it is shown that a scale factor cannot explain the observed discrepancy between the R2 patterns from the levels and the returns models. The results support the view that the two models likely represent two different economic relations and that the model choice depends on the researcher's belief and the research question at hand rather than any scale factor concerns.
Estimating demand elasticities using nonlinear pricing

Abstract Nonlinear pricing is prevalent in industries such as health care, public utilities, and telecommunications. However, this pricing scheme introduces bias into estimating elasticities for welfare analysis or policy changes. I develop a local elasticity estimation method that uses nonlinear price schedules to isolate consumers' expenditure choices from selection and simultaneity biases. This method improves over previous approaches by using commonly-available observational data and requiring only a single general monotonicity assumption. Using claims-level data on health insurance with two nonlinearities, I am able to measure two separate elasticities, and find that elasticity declines from − 0.26 to− 0.09 by the second nonlinearity. These estimates are then used to calculate moral hazard deadweight loss. This method enables estimation of many policies with nonlinear pricing which previous tools could not address.
Purchasing Art in a Market Full of Forgeries: Risks and Legal Remedies for Buyers

Since the first lawsuit against the Knoedler Gallery was filed for selling forgeries, the art world has been abuzz with stories of high-end fakes. However, forgeries are not a new phenomenon. The law of supply and demand dictates that there will be no end to the rising value of artworks done by the hands of "masters." And with soaring market prices, art forgery will proliferate as forgers find incentive in skyrocketing sales. At the heart of forgery disputes is the determination of authenticity. Who makes these determinations? How does the market and legal world handle a battle of experts? Moreover, what remedies are available to disappointed buyers? The best method of protection is to complete due diligence; however, the process is often complex and expensive. Even after completing due diligence, it is possible for buyers to be left with sophisticated fakes. What legal remedies are available to buyers?
A Behavioral Approach to Human Rights

For the last sixty years, scholars and practitioners of international human rights have paid insufficient attention to the ground level social contexts in which human rights norms are imbued with or deprived of social meaning. During the same time period, social science insights have shown that social conditions can have a significant impact on human behavior. This Article is the first to investigate the far ranging implications of behavioralism, especially behavioral insights about social influence, for the international human rights regime. It explores design implications for three broad components of the regime: the content, adjudication, and implementation of human rights. In addition, the Article addresses some of the advantages and limitations of the behavioral approach and identifies the rich but unexplored nexus of behavioralism, norms, and international law.
The Association Between Market and Exchange Rate Risks and Accounting Variables: A GARCH Model of the Japanese Banking Institutions

This study has two purposes. First, it estimates the market, interest rate, and exchange rate sensitivities (betas) of the Japanese banking institutions. Second, it investigates the relationship between the market-based measures of risk and accounting-based financial ratios. We extend the literature in three important ways. First, we employ a multi-factor GARCH model to estimate the betas. This framework incorporates non-linearities in the bank stock return modeling and allows for time-varying risk premia. Second, we investigate the determinants of market and exchange rate risk in terms of bank financial ratios. To this end, we regress the beta measures derived from the GARCH model against the corporate decision variables to determine the direction and the magnitude of the impact of the latter on the market and exchange rate risk exposures. Third, by using data on the Japanese banking institutions, we provide a comparison of the bank interest rate and exchange rate sensitivities and the strength of the links between the risk measure and the corporate decision variables between the U.S. and the Japanese banking institutions. This comparison sheds light on the robustness of the results concerning interest rate and exchange rate risk, and their determinants, across the two countries. Several interesting results are obtained. First, empirical results indicate that interest rate is only occasionally significant while market and exchange rate variables are significant for all the banks in the sample. Second, market and exchange rate risk measures do impound information in the financial ratios with the explanatory power of the market beta model being higher than that of the exchange rate beta model. Third, the association of the market-based risk measures and the financial ratios is weaker for the Japanese banks than those found for their U.S. counterparts in the existing literature.
The Role of Intellectual Property Rights in Negotiating and Planning a Research Joint Venture

Research joint ventures involve agreements among firms to engage in joint basic and applied research and development. This Article explores the importance of intellectual property rights in the formation of a research joint venture. The Article first considers the structural advantages afforded by the joint venture arrangement as to basic and applied research. Next, the Article identifies the intellectual property rights that the joint venture partners may bring into or develop during the term of their collaboration. The Article then considers the relevant antitrust implications of sharing and shared development of intellectual property rights. Finally, this Article assesses the intellectual property rights concerns that may arise at each stage of the research joint venture life cycle and offers strategies for addressing them during the negotiation and planning stages of the collaboration. The Article concludes by noting that if the firms can anticipate and manage many of the legal risks involved, they can maximize the many benefits and efficiencies that result from research collaboration.
Multidimensional Scaling of Preference Data

Multidimensional scaling represents a family of various geometric models for the multidimensional representation of the structure in data as well as the corresponding set of methods for fitting such spatial models. Its major uses in marketing include positioning, market segmentation, new-product design, consumer preference analysis, and so on. We present two popular multidimensional scaling models for the analysis of consumer preference data. The first model presented is called the vector or scalar products model that represents brands by points and consumers by vectors in a T-dimensional derived joint space. The second model is called the multidimensional unfolding or ideal point model where both brands and consumers are jointly represented by points in a T-dimensional derived joint space. We contrast the underlying utility assumptions implied by each of these two models with illustrative figures of typical joint spaces derived from each approach. An actual commercial application of consideration to buy large sports utility vehicles is provided with the empirical results from each model discussed. Implications for positioning are also revealed. Keywords: multidimensional scaling; vector model; unfolding model; positioning analysis; analysis of preference data
FINANCIAL SYSTEM ARCHITECTURE AND THE CO-EVOLUTION OF BANKS AND CAPITAL MARKETS ⁄

We study how flnancial system architecture evolves through the development of banks and flnancial markets. The predominant existing view is that banks and markets compete, which often contradicts actual patterns of development. We show that banks and markets exhibit three forms of interaction: they compete, they complement each other, and they co-evolve. The co-evolution loop is generated by two elements missing in previous analyses of flnancial system architecture: securitization and bank equity capital. As banks evolve via improvements in credit screening, they securitize higher-quality credits in the capital market. This encourages greater investor participation and spurs capital market evolution. And, if capital market evolution is spurred by exogenous shocks that cause more investors to participate in the market, banks flnd it cheaper to raise equity capital to satisfy endogenously-arising risk-sensitive capital requirements. This enables banks to serve previously-unserved high-risk borrowers, expanding banking scope and spurring bank evolution. Numerous additional results and empirical predictions are drawn out, and the implications of the analysis for bank governance and regulation are discussed.
THE INDIVIDUAL RISK ASSESSMENT OF TERRORISM

I attempt to identify the central conceptual and methodological challenges that must be overcome if the risk assessment of terrorism is to make the same progress that in recent years has distinguished the risk assessment of other forms of violence. Four principal conclusions are offered. First, clarity from the outset on what is being assessed—the risk of terrorism in the aggregate, or of specific types of terrorism, or of specific phases in the process of becoming a terrorist, or of specific roles in terrorist activity—is a prerequisite to progress in research. Second, one current approach to the risk assessment of more common violence (e.g., assault)—the approach known as structured professional judgment— usefully may be applied to the risk assessment of terrorism. However, given that many known risk factors for common violence are in fact not risk factors for violent terrorism, the substantive content of any instrument to assess the risk of terrorism will be very different from the substantive content of current instruments that address common violence. Third, since there is little existing evidence supporting the nontrivial validity of any individual risk factors for terrorism, the highest priority for research should be the identification of robust individual risk factors. Promising candidates include ideologies, affiliations, grievances, and “moral” emotions. Finally, it is highly unlikely that an instrument to assess the risk of terrorism can be validated prospectively. An infrastructure for facilitating access to known groups of terrorists and nonterrorists from the same populations may be crucial for conducting a program of scientifically rigorous and operationally relevant research on the individual risk assessment of terrorism.
Enron, Titanic, and the Perfect Storm

In this article, I explore the contention of Jeffrey Skilling, former Enron CEO, that Enron's debacle was due to a perfect storm of events. I reject his contention, arguing instead that Enron's downfall was more like Titanic's - hubris and an over-reliance on checks and balances led to Enron's downfall. I then explore how character (especially of those at the top of an organization) can lead to Enron-like disasters, and I talk about how cognitive dissonance can lead to very smart people making very stupid decisions. I end with some musings about how lawyers can learn from Enron.
The global agglomeration of multinational firms

Abstract The explosion of multinational activities in recent decades is rapidly transforming the global landscape of industrial production. But are the emerging clusters of multinational production the rule or the exception? What drives the offshore agglomeration of multinational firms in comparison to the agglomeration of domestic firms? Using a unique worldwide plant-level dataset that reports detailed location, ownership, and operation information for plants in over 100 countries, we construct a spatially continuous index of agglomeration and analyze the different patterns underlying the global economic geography of multinational and non-multinational firms. We present new stylized facts that suggest that the offshore clusters of multinationals are not a simple reflection of domestic industrial clusters. Agglomeration economies including technology diffusion and capital-good market externality play a more important role in the offshore agglomeration of multinationals than the agglomeration of domestic firms. These findings remain robust when we explore the process of agglomeration.
Consumer Mental Accounts and Implications to Selling Base Products and Add-ons

Firms in a variety of industries offer add-on products to consumers who have previously purchased a base product. We posit that consumers, in making their decisions as to whether to purchase add-ons that complement the base products, find a greater need for the value offered by the add-ons when the “unrecovered” value (i.e., price paid minus the benefits obtained so far) associated with the base products is higher. We conduct experiments that test the proposed hypothesis and examine the strategic implications of such consumer decision making to a firm that sells base product add-on pairs. Consistent with our hypothesis, the experiments show that a consumer's unrecovered value associated with the base product is positively correlated to his likelihood of purchasing the add-on. Formal modeling of this bias shows that firms may find penetration pricing strategies (such as loss leader pricing) suboptimal. Furthermore, the identified bias leads the firm to spend more resources toward enhancing both the base product and the add-on quality, especially so when the add-on will be offered before the consumer has a chance to extensively use the base product. Finally, the effect of competition in the base product market is also considered.
The effect of job flexibility on female labor market outcomes: Estimates from a search and bargaining model

Abstract In this article, we develop a search model of the labor market in which jobs are characterized by work hours’ flexibility. Workers value flexibility, which is costly for employers to provide. We estimate the model on a sample of women extracted from the CPS. The model parameters are empirically identified because the accepted wage distributions of flexible and non-flexible jobs are directly related to the preference for flexibility parameters. Results show that more than one-third of women place a small, positive value on flexibility. Women with a college degree value flexibility more than women with only a high school degree. Counterfactual experiments show that flexibility has a substantial impact on the wage distribution but a negligible impact on the unemployment rate. These results suggest that wage and schooling differences between males and females may be importantly related to flexibility.
Habitat conversion, information acquisition, and the conservation of biodiversity

Abstract We analyze two questions concerning the conservation of biodiversity in a dynamic and stochastic framework. First, given the link between natural habitats and biodiversity, when should a social planner stop the habitat conversion process? Second, what is the nexus between a social planner’s optimal conservation policy and the length of this individual’s planning horizon? We obtain the following two results. First, the optimal conservation policy calls for the social planner to wait a while, i.e. not act upon receipt of the first (1/e) fraction of all utility packets. The social planner should then stop the habitat conversion process upon receipt of the first candidate packet. The probability that the use of this optimal conservation policy will result in the conversion process being halted at the optimal point is (1/e) ≈ 0·37 . Second, because the proportion of time for which it is optimal to wait before acting is fixed, longer planning horizons result in the conservation of relatively larger stocks of biodiversity.