cssi/SciSciGPT-SciSciNet huggingface dataset:
Simultaneous Perfect Bending and Polarization Rotation of Electromagnetic Wavefront Using Chiral Gradient Metasurfaces

We introduce chiral gradient metasurfaces that allow perfect transmission of the incident wave into a desired direction and simultaneous perfect rotation of the polarization of the refracted wave with respect to the incident one. In the lossless limit, transmission can reach 100% with a single metasurface layer. Besides using gradient polarization densities that provide bending of the refracted wave with respect to the incident one, the use of metasurface inclusions that are chiral allows the polarization of the refracted wave to be rotated. We suggest a possible realization of the proposed device by discretizing the required equivalent-surface polarization densities and synthesizing the chiral discrete polarizabilities with properly sized helical inclusions at each discretization point. By using only a single optically thin layer of chiral inclusions, we are able to deflect a normal incident plane wave to a refracted plane wave at ${45}^{\ensuremath{\circ}}$ with a $72\mathrm{%}$ power efficiency that is accompanied by a ${90}^{\ensuremath{\circ}}$ polarization rotation. The proposed concepts and the design method may find practical applications in polarization-rotation devices in microwaves as well as in optics, especially when the incident power is required to be deflected.
Thermoelectric properties of semimetals

Heavily doped semiconductors are by far the most studied class of materials for thermoelectric applications in the past several decades. They have Seebeck coefficient values which are 2--3 orders of magnitude higher than metals, making them attractive for thermoelectric applications. Conventional wisdom suggests that the optimal band gap of a semiconductor to achieve the largest power factor should be between 6 and 10 ${k}_{B}T$, yet the highest power factor materials known up to now do not have a band gap. In this paper, we show that semimetals with very small or no band gap, but high asymmetry between their conduction and valence bands, can also have large Seebeck coefficient values on the order of 200 $\ensuremath{\mu}\text{V/K}$, which is near the optimum value for thermoelectric applications. We have studied the band structure of a class of 18 semimetals using first principles calculations and calculated their Seebeck coefficient using the linearized Boltzmann equation within the constant relaxation time approximation. We conclude that despite the absence of the band gap, semimetals with band asymmetry can have good thermoelectric performance. We analyze the metrics often used to describe thermoelectric properties of materials and show that the ratio of electron and hole mass of density of states is a key parameter resulting in high Seebeck coefficient values in semimetals. This work is therefore suggesting some high thermoelectric performance materials could be of semimetallic nature.
Oxidation of the Interiors of Carbide Exoplanets

Astrophysical measurements have shown that some stars have sufficiently high carbon-to-oxygen ratios such that the planets they host would be mainly composed of carbides instead of silicates. We studied the behavior of silicon carbide in the presence of water under the high pressure-temperature conditions relevant to planetary interiors in the laser-heated diamond-anvil cell (LHDAC). When reacting with water, silicon carbide converts to silica (stishovite) and diamond at pressures up to 50 GPa and temperatures up to 2500 K: SiC + 2H$_2$O -> SiO$_2$ + C + 2H$_2$. Therefore, if water can be incorporated into carbide planets during their formation or through later delivery, they could be oxidized and have mineralogy dominated by silicates and diamond in their interiors. The reaction could produce CH$_4$ at shallower depths and H$_2$ at greater depths which could be degassed from the interior, causing the atmospheres of the converted carbon planets to be rich in reducing gases. Excess water after the reaction can be stored in dense silica polymorphs in the interiors of the converted carbon planets. Such conversion of mineralogy to diamond and silicates would decrease the density of carbon-rich planet, making the converted planets distinct from silicate planets in mass-radius relations for the 2-8 Earth mass range.
Modeling the Infrared Spectrum of the Earth-Moon System: Implications for the Detection and Characterization of Earthlike Extrasolar Planets and their Moonlike Companions

The Moon maintains large surface temperatures on its illuminated hemisphere and can contribute significant amounts of flux to spatially unresolved thermal infrared (IR) observations of the Earth-Moon system, especially at wavelengths where Earth's atmosphere is absorbing. In this paper we investigate the effects of an unresolved companion on IR observations of Earthlike exoplanets. For an extrasolar twin Earth-Moon system observed at full phase at IR wavelengths, the Moon consistently comprises about 20% of the total signal, approaches 30% of the signal in the 9.6 μm ozone band and the 15 μm carbon dioxide band, makes up as much as 80% of the signal in the 6.3 μm water band, and more than 90% of the signal in the 4.3 μm carbon dioxide band. These excesses translate to inferred brightness temperatures for Earth that are too large by 20-40 K and demonstrate that the presence of undetected satellites can have significant impacts on the spectroscopic characterization of exoplanets. The thermal flux contribution from an airless companion depends strongly on phase, implying that observations of exoplanets should be taken when the star-planet-observer angle (i.e., phase angle) is as large as feasibly possible if contributions from companions are to be minimized. We show that, by differencing IR observations of an Earth twin with a companion taken at both gibbous and crescent phases, Moonlike satellites may be detectable by future exoplanet characterization missions for a wide range of system inclinations.
Dielectric Engineered Tunnel Field-Effect Transistor

The dielectric engineered tunnel field-effect transistor (DE-TFET) as a high-performance steep transistor is proposed. In this device, a combination of high- $k$ and low- $k$ dielectrics results in a high electric field at the tunnel junction. As a result, a record ON-current of $\sim 1000~\mu \text{A}/\mu \text{m}$ and a subthreshold swing (SS) below 20 mV/decade are predicted for WTe2 DE-TFET. The proposed TFET works based on a homojunction channel and electrically doped contacts both of which are immune to interface states, dopant fluctuations, and dopant states in the bandgap, which typically deteriorate the OFF-state performance and SS in the conventional TFETs.
On the Existence of Solitary Traveling Waves for Generalized Hertzian Chains

We consider the question of existence of “bell-shaped” (i.e., nonincreasing for x>0 and nondecreasing for x<0) traveling waves for the strain variable of the generalized Hertzian model describing, in the special case of a p=3/2 exponent, the dynamics of a granular chain. The proof of existence of such waves is based on the English and Pego (Proc. Am. Math. Soc. 133:1763, 2005) formulation of the problem. More specifically, we construct an appropriate energy functional, for which we show that the constrained minimization problem over bell-shaped entries has a solution. We also provide an alternative proof of the Friesecke–Wattis result (Commun. Math. Phys. 161:391, 1994) by using the same approach (but where the minimization is not constrained over bell-shaped curves). We briefly discuss and illustrate numerically the implications on the doubly exponential decay properties of the waves, as well as touch upon the modifications of these properties in the presence of a finite precompression force in the model.
Expressive Interviewing: A Conversational System for Coping with COVID-19

The ongoing COVID-19 pandemic has raised concerns for many regarding personal and public health implications, financial security and economic stability. Alongside many other unprecedented challenges, there are increasing concerns over social isolation and mental health. We introduce \textit{Expressive Interviewing}--an interview-style conversational system that draws on ideas from motivational interviewing and expressive writing. Expressive Interviewing seeks to encourage users to express their thoughts and feelings through writing by asking them questions about how COVID-19 has impacted their lives. We present relevant aspects of the system's design and implementation as well as quantitative and qualitative analyses of user interactions with the system. In addition, we conduct a comparative evaluation with a general purpose dialogue system for mental health that shows our system potential in helping users to cope with COVID-19 issues.
Searching through functional space reveals distributed visual, auditory, and semantic coding in the human brain.

The extent to which brain functions are localized or distributed is a foundational question in neuroscience. In the human brain, common fMRI methods such as cluster correction, atlas parcellation, and anatomical searchlight are biased by design toward finding localized representations. Here we introduce the functional searchlight approach as an alternative to anatomical searchlight analysis, the most commonly used exploratory multivariate fMRI technique. Functional searchlight removes any anatomical bias by grouping voxels based only on functional similarity and ignoring anatomical proximity. We report evidence that visual and auditory features from deep neural networks and semantic features from a natural language processing model, as well as object representations, are more widely distributed across the brain than previously acknowledged and that functional searchlight can improve model-based similarity and decoding accuracy. This approach provides a new way to evaluate and constrain computational models with brain activity and pushes our understanding of human brain function further along the spectrum from strict modularity toward distributed representation
GeLaTO: Generative Latent Textured Objects

Accurate modeling of 3D objects exhibiting transparency, reflections and thin structures is an extremely challenging problem. Inspired by billboards and geometric proxies used in computer graphics, this paper proposes Generative Latent Textured Objects (GeLaTO), a compact representation that combines a set of coarse shape proxies defining low frequency geometry with learned neural textures, to encode both medium and fine scale geometry as well as view-dependent appearance. To generate the proxies’ textures, we learn a joint latent space allowing category-level appearance and geometry interpolation. The proxies are independently rasterized with their corresponding neural texture and composited using a U-Net, which generates an output photorealistic image including an alpha map. We demonstrate the effectiveness of our approach by reconstructing complex objects from a sparse set of views. We show results on a dataset of real images of eyeglasses frames, which are particularly challenging to reconstruct using classical methods. We also demonstrate that these coarse proxies can be handcrafted when the underlying object geometry is easy to model, like eyeglasses, or generated using a neural network for more complex categories, such as cars.
Characterizing drug mentions in COVID-19 Twitter Chatter.

Since the classification of COVID-19 as a global pandemic, there have been many attempts to treat and contain the virus. Although there is no specific antiviral treatment recommended for COVID-19, there are several drugs that can potentially help with symptoms. In this work, we mined a large twitter dataset of 424 million tweets of COVID-19 chatter to identify discourse around drug mentions. While seemingly a straightforward task, due to the informal nature of language use in Twitter, we demonstrate the need of machine learning alongside traditional automated methods to aid in this task. By applying these complementary methods, we are able to recover almost 15% additional data, making misspelling handling a needed task as a pre-processing step when dealing with social media data.
Transformed lymphoma: what should I do now?

Although the majority of indolent lymphomas (focusing on follicular lymphoma [FL]) have a prolonged waxing and waning course, a portion of patients experience histologic transformation (HT) to either diffuse large B-cell lymphoma or a higher-grade morphology, often with acquisition of MYC and BCL2 and/or BCL6 rearrangements (high-grade B-cell lymphoma-double-hit lymphoma/triple-hit lymphoma). The overall incidence of HT and transformed follicular lymphoma (tFL) may be declining, but outcomes remain inferior to those in simple indolent lymphoma progression. Recent data suggest that the majority of HT cases occur in higher-risk patients with FL, and they occur early after initial chemoimmunotherapy, comprising the majority of patients with progression of disease within 24 months. This latter point emphasizes the need for a sufficient biopsy at relapse in FL. Treatment options depend on the prior therapy for the indolent component as well as the histology at relapse, but they generally follow several principles discussed in this article. Anthracycline-naive patients have the best outcomes if there is HT, and responses to R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) are similar to those of patients with de novo diffuse large B-cell lymphoma. Patients with anthracycline exposure prior to transformation have the best outcomes with salvage chemotherapy and a consolidative autologous stem cell transplant. However, a major challenge is the management of patients with tFL who experience relapse early after bendamustine-based treatment, in whom the role of consolidative transplant after anthracycline-based treatment is unclear. In the past several years, cellular therapy has emerged as an important tool for some but not all patients with tFL. This review focuses on the nuances of managing tFL.
A Shared Vision? Understanding Barriers to Internationalization.

This mixed methods study identified obstacles to internationalization in the Republic of Korea by examining differences in stakeholder perceptions at a large, private regional university. Questionnaire data (n = 127) and interview transcripts (n = 17) were analyzed. Independent samples t-tests of Korean and international stakeholders (administrators, faculty, and students) and one-way ANOVAs of faculty, students, and administrative staff were conducted to detect differences in the perceived importance and quality of internationalization at the university. Stakeholder groups shared high perceived importance for internationalization, but internationals perceived quality to be lower than Koreans (p = .023), and faculty lower than both students (p = .03) and administrative staff (p = .025). Qualitative analysis revealed differences rooted in inconsistent conceptualizations of internationalization among stakeholder groups. Resentment, confusion, a lack of communication, and low organizational commitment emerged as barriers. Without a change in approach, internationalization efforts at Korean institutions of higher education will likely stall.
Efficacy of face masks, neck gaiters and face shields for reducing the expulsion of simulated cough-generated aerosols

Face masks are recommended to reduce community transmission of SARS-CoV-2. One of the primary benefits of face masks and other coverings is as source control devices to reduce the expulsion of resp...
Gonality and genus of canonical components of character varieties

Throughout the paper,M will always denote a complete, orientable finite volume hyperbolic 3-manifold with cusps. By abuse of notation we will denote by ∂M to be the boundary of the compact manifold obtained from M by truncating the cusps. Given such a manifold, the SL2(C) character variety of M , X(M), is a complex algebraic set associated to representations of π1(M)→ SL2(C) (see §4 for more details). Work of Thurston showed that any irreducible component of such a variety containing the character of a discrete faithful representation has complex dimension equal to the number of cusps of M . Such components are called canonical components and are denoted X0(M). Character varieties have been fundamental tools in studying the topology of M (we refer the reader to [23] for more), and canonical components carry a wealth of topological information aboutM , including containing subvarieties associated to Dehn fillings of M . WhenM has exactly one cusp, any canonical component is a complex curve. The aim of this paper is to study how some of the natural invariants of these complex curves correspond to the underlying manifold M . In particular, we concentrate on how the gonality of these curves behaves in families of Dehn fillings on 2-cusped hyperbolic manifolds. More precisely, we study families of 1-cusped 3-manifolds which are obtained by Dehn filling of a single cusp of a fixed 2-cusped hyperbolic 3-manifold, M . We write M(−, r) to denote the manifold obtained by r = p/q filling of the second cusp of M . To state our results we introduce the following notation. If X is a complex curve, we write γ(X) to denote the gonality of X, g(X) to be the (geometric) genus of X and d(X) to be the degree (of the specified embedding) of X. The gonality of a curve is the lowest degree of a map from that curve to C. Unlike genus, gonality is not a topological invariant of curves, but rather is intimately connected to the geometry of the curve. There are connections between gonality and genus, most notably the Brill-Noether theorem which gives an upper bound for gonality in terms of genus (see § 7) but in some sense these are orthogonal invariants. For example, all hyperelliptic curves all have gonality two, but can have arbitrarily high genus. Moreover, for g > 2, there are curves of genus g of different gonality. We refer the reader to § 3 for precise definitions. Our first theorem is the following.
Plant carbohydrate depletion impairs water relations and spreads via ectomycorrhizal networks

Under prolonged drought and reduced photosynthesis, plants consume stored nonstructural carbohydrates (NSCs). Stored NSC depletion may impair the regulation of plant water balance, but the underlying mechanisms are poorly understood, and whether such mechanisms are independent of plant water deficit is not known. If so, carbon costs of fungal symbionts could indirectly influence plant drought tolerance through stored NSC depletion. We connected well-watered Pinus ponderosa seedling pairs via ectomycorrhizal (EM) networks where one seedling was shaded (D) and the other kept illuminated (LD) and compared responses to seedling pairs in full light (L). We measured plant NSCs, osmotic and water potential, and transfer of 13 CO2 through EM to explore mechanisms linking stored NSCs to plant water balance regulation and identify potential tradeoffs between plant water retention and EM fungi under carbon-limiting conditions. NSCs decreased from L to LD to D seedlings. Even without drought, NSC depletion impaired osmoregulation and turgor maintenance, both of which are critical for drought tolerance. Importantly, EM networks propagated NSC depletion and its negative effects on water retention from carbon stressed to nonstressed hosts. We demonstrate that NSC storage depletion influences turgor maintenance independently of plant water deficit and reveal carbon allocation tradeoffs between supporting fungal symbionts and retaining water.
Coarse-grained nucleic acid–protein model for hybrid nanotechnology

The emerging field of hybrid DNA–protein nanotechnology brings with it the potential for many novel materials which combine the addressability of DNA nanotechnology with the versatility of protein interactions. However, the design and computational study of these hybrid structures is difficult due to the system sizes involved. To aid in the design and in silico analysis process, we introduce here a coarse-grained DNA/RNA–protein model that extends the oxDNA/oxRNA models of DNA/RNA with a coarse-grained model of proteins based on an anisotropic network model representation. Fully equipped with analysis scripts and visualization, our model aims to facilitate hybrid nanomaterial design towards eventual experimental realization, as well as enabling study of biological complexes. We further demonstrate its usage by simulating DNA–protein nanocage, DNA wrapped around histones, and a nascent RNA in polymerase.
DMRG study of strongly interacting $\mathbb{Z}_2$ flatbands: a toy model inspired by twisted bilayer graphene

Strong interactions between electrons occupying bands of opposite (or like) topological quantum numbers (Chern$=\pm1$), and with flat dispersion, are studied by using lowest Landau level (LLL) wavefunctions. More precisely, we determine the ground states for two scenarios at half-filling: (i) LLL's with opposite sign of magnetic field, and therefore opposite Chern number; and (ii) LLL's with the same magnetic field. In the first scenario -- which we argue to be a toy model inspired by the chirally symmetric continuum model for twisted bilayer graphene -- the opposite Chern LLL's are Kramer pairs, and thus there exists time-reversal symmetry ($\mathbb{Z}_2$). Turning on repulsive interactions drives the system to spontaneously break time-reversal symmetry -- a quantum anomalous Hall state described by one particle per LLL orbital, either all positive Chern $|++\cdots+>$ or all negative $|--\cdots->$. If instead, interactions are taken between electrons of like-Chern number, the ground state is an $SU(2)$ ferromagnet, with total spin pointing along an arbitrary direction, as with the $\nu=1$ spin-$\frac{1}{2}$ quantum Hall ferromagnet. The ground states and some of their excitations for both of these scenarios are argued analytically, and further complimented by density matrix renormalization group (DMRG) and exact diagonalization.
Optimal Randomized Complete Visibility on a Grid for Asynchronous Robots with Lights

We consider the distributed setting of N autonomous mobile robots that operate in Look-Compute-Move (LCM) cycles and communicate with other robots using colored lights (the robots with lights model. This model assumes obstructed visibility where a robot cannot see another robot if a third robot is positioned between them on the straight line connecting them. In this paper, we consider robot movements to be on a grid (integer plane) of unbounded size. In any given step a robot positioned at a grid point can move only to an adjacent grid point to its north, south, east or west. The grid setting naturally discretizes the 2-dimensional plane and finds applications in many real-life robotic systems. The Complete Visibility problem is to reposition N autonomous robots (starting at arbitrary, but distinct, initial positions) so that, on termination, each robot is visible to all others. The objective in this problem is to simultaneously minimize (or provide trade-off between) two fundamental performance metrics: (i) time to solve Complete Visibility and (ii) area occupied by the solution. We also consider the number of distinct colors used by each robot light. We provide the first O(max{D,N})-time algorithm for Complete Visibility in the asynchronous setting, where D is the diameter of the initial configuration. The area occupied by the final configuration is O(N^2); both the time and area are optimal. The time is randomized if no symmetry breaking mechanism is available for the robots. The number of colors used in our algorithm depends on whether leader election is required or not: (i) 17 colors if leader election is not required and (ii) 32 colors if leader election is required.
Limiting probability measures

The coordinates along any fixed direction(s), of points on the sphere $S^{n-1}(\sqrt{n})$, roughly follow a standard Gaussian distribution as $n$ approaches infinity. We revisit this classical result from a nonstandard analysis perspective, providing a new proof by working with hyperfinite dimensional spheres. We also set up a nonstandard theory for the asymptotic behavior of integrals over varying domains in general. We obtain a new proof of the Riemann--Lebesgue lemma as a by-product of this theory. We finally show that for any function $f \co \mathbb{R}^k \to \mathbb{R}$ with finite Gaussian moment of an order larger than one, its expectation is given by a Loeb integral integral over a hyperfinite dimensional sphere. Some useful inequalities between high-dimensional spherical means of $f$ and its Gaussian mean are obtained in order to complete the above proof.
Recursive Spectral Analysis-Based Diagnostic With Application to Electrohydraulic Actuators

This letter presents the diagnostic of electrohydraulic actuators. Different types of faults common in practice are considered such as a pump fault, abnormal viscous friction, oil contamination, and internal or external oil leakage. The entire diagnostic consists of two components: 1) reference tracking control; 2) recursive harmonic analysis. Firstly, the robust repetitive control is used such that the actuator position follows the harmonic reference signal. Secondly, the Fourier transforms of the control input at multiple harmonics are calculated recursively from sliding discrete Fourier transform. Instead of the raw control input, the modulated input signal is employed for better efficiency and robustness. The diagnostic decision is made based on distribution of the Fourier transforms. The effectiveness of the proposed method is demonstrated with numerical simulations. Diagnostic performance with different sizes of the sliding window is analyzed in terms of separation metrics, as a critical design parameter.
Harvesting energy from a periodic heat bath

The context of the present paper is stochastic thermodynamics–an approach to nonequilibrium thermodynamics rooted within the broader framework of stochastic control. In contrast to the classical paradigm of Carnot engines, we herein propose to consider thermodynamic processes with periodic continuously varying temperature of a heat bath and study questions of maximal power and efficiency for two idealized cases, overdamped (first-order) and underdamped (second-order) stochastic models. We highlight properties of optimal periodic control, derive and numerically validate approximate formulae for the optimal performance (power and efficiency).
Financial Firm Bankruptcy and Contagion

The Lehman bankruptcy highlights the potential for interconnectedness to cause negative externalities through counterparty contagion, but the externalities may also arise from information contagion. We examine troubled financial firms and find that both channels are significant factors in creating spillover effects. Counterparty contagion is greater in cases of riskier firms and larger and more complex exposures. However, the counterparty exposures are small, especially among banks that face diversification regulations, and do not typically cause a cascade of failures. Information contagion is stronger for rivals in the same markets and has a larger impact in cases of distress than in bankruptcies.
Party Affiliation, Partisanship, and Political Beliefs: A Field Experiment

Partisanship is strongly correlated with attitudes and behavior, but it is unclear from this pattern whether partisan identity has a causal effect on political behavior and attitudes. We report the results of a field experiment that investigates the causal effect of party identification. Prior to the February 2008 Connecticut presidential primary, researchers sent a mailing to a random sample of unaffiliated registered voters who, in a pretreatment survey, leaned toward a political party. The mailing informed the subjects that only voters registered with a party were able to participate in the upcoming presidential primary. Subjects were surveyed again in June 2008. Comparing posttreatment survey responses to subjects’ baseline survey responses, we find that those reminded of the need to register with a party were more likely to identify with a party and showed stronger partisanship. Further, we find that the treatment group also demonstrated greater concordance than the control group between their pretreatment latent partisanship and their posttreatment reported voting behavior and intentions and evaluations of partisan figures. Thus, our treatment, which appears to have caused a strengthening of partisan identity, also appears to have caused a shift in subjects’ candidate preferences and evaluations of salient political figures. This finding is consistent with the claim that partisanship is an active force changing how citizens behave in and perceive the political world.
Where Does State Street Lead? A First Look at Finance Patents, 1971 to 2000

This paper empirically examines patents for financial formulas and methods, whose patentability was recently confirmed in the litigation between State Street Bank and Trust and Signature Financial Group. The number of such filings and awards has been accelerating. Patent filings by academics have been very infrequent, which appears to be a consequence of a lack of awareness or interest on the part of faculty members, rather than any fundamental unsuitability of their research for patenting. The failure to cite academic research in this area appears to be problematic and may reflect patent examiners' limited exposure to finance research and patents. Copyright The American Finance Association 2002.
Gigahertz Phononic Integrated Circuits on Thin-Film Lithium Niobate on Sapphire

Phononic integrated circuits that guide acoustic waves at wavelength scale offer great potential for devices in communications, sensing, and quantum technologies. Unfortunately, conventional phononic waveguides either are suspended, which prevents large-scale integration, or suffer from inefficient acoustic wave transduction. Surmounting these issues, this work implements unreleased-rib phononic circuits operating at 3.4 GHz with efficient, compact transducers in a thin-film platform of lithium niobate on sapphire. These circuits allow the authors to demonstrate mass sensing, high-quality resonators, and the characterization of low-power acoustic four-wave mixing.
Asset prices and the fundamentals: a Q test

A test of the relationship between financial asset values and the fundamentals is presented. The test is an indirect test based on Tobin's (1969) q model of investment. The advantage of this test is that it avoids conditioning on a specific model of equilibrium returns by substituting an observable proxy, capital, for the unobservable fundamental value of the firm. It is shown that under mild restrictions, the value of capital and the financial value of the firm should move together even if marginal or average q does not accurately describe the actual investment decision rule. Average q is a mean reverting process. The results of tests for violations of the mean reversion restriction are presented. The tests cannot reject the unit root null hypothesis for a long annual sample from 1926 to 1988 or a quarterly post-World War II sample. The power of the tests is examined with Monte Carlo simulations. The simulations show that the tests have good power until the serial correlation in the series gets quite hig...
REEVALUATING THE ROLE OF TRADE AGREEMENTS: DOES INVESTMENT GLOBALIZATION MAKE THE WTO OBSOLETE?

Abstract International ownership alters the role of multilateral trade institutions by redefining pecuniary externalities among countries. Regardless of the underlying cause – whether foreign direct investment, international portfolio diversification, cross-country mergers, or multinational firms — international ownership can mitigate incentives that lead large countries to set inefficiently high tariffs. At the same time, however, foreign ownership introduces the potential for expropriation by investment-host countries, which can extract rent from foreign owners by manipulating local prices. The basic principle of reciprocity continues to serve as an important guide to efficiency, though its application must account for the pattern of international ownership in addition to traditional measures of market access.
STRATEGIC EFFECTS OF THREE-PART TARIFFS UNDER OLIGOPOLY

The distinct element of a three-part tariff (3PT), compared with linear pricing (LP) or a two-part tariff, is its quantity target within which the marginal price is zero. This quantity target instrument enriches the firm's strategy set in dictating the competition to a specific level, even in the absence of a usual price discrimination motive. With general differentiated linear demands, the competitive effect of a 3PT in contrast to LP depends on the degree of substitutability between products: Competition is intensified when two products are more differentiated, yet softened when two products are more substitutable.
Medium-term determinants of current accounts in industrial and developing countries: an empirical exploration

Abstract This paper provides an empirical investigation of the medium-term determinants of current accounts for a large sample of industrial and developing countries, utilizing an approach that highlights macroeconomic determinants of longer-term saving and investment balances. Cross-section and panel regression techniques are used to characterize the variation of the current account across countries and over time. We find that current account balances are positively correlated with government budget balances and initial stocks of net foreign assets. Among developing countries, measures of financial deepening are positively associated with current account balances while indicators of openness to international trade are negatively correlated with current account balances.
The Crime of Political Genocide: Repairing the Genocide Convention’s Blind Spot

This chapter discusses the political compromises that occurred during the drafting of the Genocide Convention. The jus cogens prohibition of political genocide is expressed in national legislation. The chapter describes the atrocities perpetrated by the Khmer Rouge in Cambodia to demonstrate the shortfalls of the definition of genocide in the Genocide Convention. It also describes the scope of the jus cogens prohibition of genocide, and argues that treaty provisions such as Article II carry no legal weight when they conflict with a jus cogens norm as a higher form of law. The chapter also argues that the Genocide Convention is not the sole authority on the crime of genocide. It provides political persecution accompanied other forms of persecution, so that the victims and perpetrators of the Khmer Rouge era would receive disparate justice as a result of the Genocide Convention's blind spot.
A Fundamental Prediction Error: Self-Others Discrepancies in Risk Preference

This research examined whether people can accurately predict the risk preferences of others. Three experiments featuring different designs revealed a systematic bias: that participants predicted others to be more risk seeking than themselves in risky choices, regardless of whether the choices were between options with negative outcomes or with positive outcomes. This self-others discrepancy persisted even if a monetary incentive was offered for accurate prediction. However, this discrepancy occurred only if the target of prediction was abstract and vanished if the target was vivid. A risk-as-feelings hypothesis was introduced to explain these findings.
Fox News and political knowledge

Abstract The effects of partisan media on political knowledge are theoretically ambiguous. Knowledge effects are important because of their close connection to welfare effects, but the existing empirical literature on knowledge is limited. We study the knowledge effects of the Fox News Channel. Following DellaVigna and Kaplan (2007), we exploit naturally random variation in Fox's availability to identify causal effects. We use knowledge survey data from 2000, 2004 and 2008; our final sample has nearly one million question-level observations. We first confirm and expand on previous findings of Fox effects on voting. We then present an array of results from our knowledge analysis. While average effects (across issues), over the full time-frame are near-zero and most precise, we find evidence of positive effects both for issues that were more favorable to Republicans and for issues that Fox covered more often, and negative effects for issues Fox neglected. We also present evidence of Fox being associated with a decline in newspaper readership.
Effective Plea Bargaining Counsel

Fifty years ago, Clarence Earl Gideon needed an effective trial attorney. The Supreme Court agreed with Gideon that the Sixth Amendment guaranteed him the right to counsel at trial. Recently, Galin Frye and Anthony Cooper also needed effective representation. These two men, unlike Gideon, wanted to plead guilty and thus needed effective plea bargaining counsel. However, their attorneys failed to represent them effectively, and the Supreme Court—recognizing the reality that ninety-five percent of all convictions follow guilty pleas and not trials—ruled in favor of Frye and Cooper. If negotiation is a critical stage in a system that consists almost entirely of bargaining, is there a constitutional right to the effective assistance of plea bargaining counsel? If so, is it possible to define the contours of such a right? The concept of a right to an effective bargainer seems radical, yet obvious; fraught with difficulties, yet in urgent need of greater attention. In this Essay, I argue that the Court’s broad statements in Missouri v. Frye, Lafler v. Cooper, and its 2010 decision in Padilla v. Kentucky about the critical role defense counsel plays in plea negotiations strongly support a right to effective plea bargaining counsel. Any right to effective bargaining should be judged—as other ineffective assistance claims are judged—by counsel’s success or failure in following prevailing professional norms. This Essay discusses the numerous professional standards that support the notion that defense counsel should act effectively when the prosecution seeks to negotiate and should initiate negotiations when the prosecution fails to do so, if it serves the client’s goals. The objections to constitutional regulation of plea bargaining include the claims that negotiation is a nuanced art conducted behind closed doors that is difficult to capture in standards and that regulating bargaining will open floodgates to future litigation. While real, these are manageable challenges that do not outweigh the need to give meaning to the constitutional right to effective counsel. After all, in a criminal justice system that is largely composed of plea bargains, what is effective assistance of counsel if it does not encompass effectiveness within the plea negotiation process? author. Professor of Law and Co-Director, Criminal Justice Clinic, American University, Washington College of Law. With thanks to Stephanos Bibas, Josh Bowers, Mary Holland, Cecelia Klingele, Juliet Stumpf, Andrew Taslitz, Ronald Wright, and participants in the Washington College of Law clinic writing workshop. Kathryn Wilson provided excellent research assistance. effective plea bargaining counsel
The dynamics of reputations

We study the endogenous dynamics of reputations in a system consisting of firms with long horizons that provide goods or services with varying levels of quality, and large numbers of customers who assign to them reputations on the basis of the quality levels that they experience when interacting with them. We show that for given discounts of the past on the part of the customers, and of effort levels on the part of the firms, the dynamics can lead to either well defined equilibria or persistent nonlinear oscillations in the number of customers visiting a firm, implying unstable reputations. We establish the criteria under which equilibria are stable and also show the existence of large transients which can also render fixed points unattainable within reasonable times. Moreover we establish that the timescales for the buildup and decay of reputations in the case of private information are much longer that those involving public information. This provides a plausible explanation for the rather sudden increase and collapse of reputations in a number of much publicized cases.
Optimal Income Transfer Programs: Intensive versus Extensive Labor Supply Responses

This paper analyzes optimal income transfers for low incomes. Labor supply responses are modeled along the intensive margin (intensity of work on the job) and along the extensive margin (participation into the labor force). When behavioral responses are concentrated along the intensive margin, the optimal transfer program is a classical Negative Income Tax program with a substantial guaranteed income support and a large phasing-out tax rate. However, when behavioral responses are concentrated along the extensive margin, the optimal transfer program is similar to the Earned Income Tax Credit with negative marginal tax rates at low income levels and a small guaranteed income. Carefully calibrated numerical simulations are provided.
Detention as Targeting: Standards of Certainty and Detention of Suspected Terrorists

To the extent that a state can detain terrorists pursuant to the law of war, how certain must the state be in distinguishing suspected terrorists from nonterrorists? This Article shows that the law of war can and should be interpreted or supplemented to account for the exceptional aspects of an indefinite conflict against a transnational terrorist organization by analogizing detention to military targeting and extrapolating from targeting rules. A targeting approach to the detention standard-of-certainty question provides a methodology for balancing security and liberty interests that helps fill a gap in detention law and helps answer important substantive questions left open by recent Supreme Court detention cases, including Boumediene v. Bush. Targeting rules include a reasonable care standard for dealing with the practical and moral problems of protecting innocent civilians from injury amid clouds of doubt and misinformation, though the application of this standard in the detention context must account for differences such as a temporal dimension, available procedural mechanisms, and political and strategic context. Applying a targeting law methodology, this Article offers a law of war critique of past and current U.S. government detention policies. It recommends several ways to remedy them, including through an escalating standard of certainty as time in detention elapses, comparative consideration of accuracy-enhancing adjudication procedures, and greater decisionmaking transparency.
How does the stock market absorb shocks

Abstract Using a comprehensive set of news stories, we find a stark difference in market responses to positive and negative price shocks accompanied by new information. When there is a news story about a firm, positive price shocks are followed by reversal, while negative ones result in drift. This is interpreted as the stock market overreaction to good news and underreaction to bad news. These seemingly contradictory results can be explained in a single framework, considering the interaction of retail investors with attention bias, and arbitrageurs with short-run capital constraints. Consistent with this hypothesis, we find that both patterns are stronger when the attention bias is stronger, and when the arbitrage capital is scarce.
Entry and Predation: British Shipping Cartels 1879–1929

I examine the outcomes of cases of entry by merchant shipping lines into established markets around the turn of the century. These established markets are completely dominated by an incumbent cartel composed of several member shipping lines. The cartel makes the decision whether or not to begin a price war against the entrant; some entrants are formally admitted to the cartel without any conflict. I use characteristics of the entrant to predict whether or not the entrant will encounter a price war conditional on entering. I find that weaker entrants are fought, where “weaker” means having fewer financial resources, less experience, smaller size, or poor trade conditions. The empirical results provide most support for the long-purse theory of predation. Due to the small number of observations available, 47, I discuss qualitative evidence (such as predatory intent expressed in correspondence between cartel members) that supports the empirical results. The results are also found to be robust to misclassification of the dependent variable, which is a particular concern when dealing with historical data.
THE EFFECT OF STATISTICAL DISCRIMINATION ON BLACK-WHITE WAGE INEQUALITY: ESTIMATING A MODEL WITH MULTIPLE EQUILIBRIA ∗

This article presents the structural estimation of the parameters of a statistical discrimination model. Although the model is capable of displaying multiple equilibria, an estimation strategy that identifies both the model parameters and the equilibrium selected by the economic agents is developed and empirically implemented. A comparison between the selected equilibria and the other potential equilibria reveals that the decline in wage inequality experienced in the U.S. economy cannot be attributed to changes in the equilibrium selection. Nonetheless, a counterfactual experiment shows that in a color-blind society blacks' wage would have been on average more than 20% higher.
Dynamic Style Preferences of Individual Investors and Stock Returns

This study shows that individual investors systematically shift their preferences across extreme style portfolios (small vs. large, value vs. growth). These preference shifts are influenced by past style returns and earnings differentials, and advice from investment newsletters, but are unaffected by innovations in macroeconomic variables or shifts in expectations about future cash flows. Furthermore, investors’ dynamic style preferences influence returns along multiple dimensions: i) the contemporaneous relation between style returns and style-level preference shifts is strong, ii) there is weak evidence of style return predictability, and iii) the correlations among stocks within a style increase when investors move into or out of the style with greater intensity. Overall, the results indicate that stock categorization influences investors’ portfolio decisions and stock returns.
Are Cryptocurrencies 'Super' Tax Havens?

I describe the mechanisms by which cryptocurrencies — a subcategory of virtual currencies — could replace tax havens as the weapon-of-choice for tax-evaders. I argue such outcome is reasonably expected in the foreseeable future due to the contemporary convergence of two processes. The first process is the increasing popularity of cryptocurrencies, of which Bitcoin is the most widely recognized example. The second process is the transformation of financial intermediaries to agents in the service of tax authorities, as part of the fight against offshore tax evasion. Financial institutions are faced with increased governmental pressure to deliver information about account holders, to withhold taxes from earnings accumulating in financial accounts, and to remit such taxes to taxing authorities around the world. Significantly, cryptocurrencies possess all the traditional characteristics that tax haves do; Earnings are not subject to taxation, and taxpayers’ anonymity is maintained. The operation of cryptocurrencies, however, is not dependent on the existence of financial intermediaries. Thus, cryptocurrencies have the potential of defeating the recent successes of governments in battling offshore tax evasion. I further suggest that while governments have paid some attention to this issue, they have so far failed to identify the acuteness of the potential problem.