cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantum Impurity in a Magnetic Environment

A unified perspective is given on a number of different problems involving the coupling of a localized quantum spin degree of freedom to the low energy excitations of an antiferromagnet, a spin glass, or a Kondo insulator. The problems are related to those in the class often referred to as “Bose Kondo.”
Is There a Disk of Satellites around the Milky Way

The "disk of satellites" (DoS) around the Milky Way is a highly debated topic with conflicting interpretations of observations and their theoretical models. We perform a comprehensive analysis of all of the dwarfs detected in the Milky Way and find that the DoS structure depends strongly on the plane identification method and the sample size. In particular, we demonstrate that a small sample size can artificially produce a highly anisotropic spatial distribution and a strong clustering of the angular momentum of the satellites. Moreover, we calculate the evolution of the 11 classical satellites with proper motion measurements and find that the thin DoS in which they currently reside is transient. Furthermore, we analyze two cosmological simulations using the same initial conditions of a Milky-Way-sized galaxy, an N-body run with dark matter only, and a hydrodynamic one with both baryonic and dark matter, and find that the hydrodynamic simulation produces a more anisotropic distribution of satellites than the N-body one. Our results suggest that an anisotropic distribution of satellites in galaxies can originate from baryonic processes in the hierarchical structure formation model, but the claimed highly flattened, coherently rotating DoS of the Milky Way may be biased by the small-number selection effect. These findings may help resolve the contradictory claims of DoS in galaxies and the discrepancy among numerical simulations.
Is the Effective Field Theory of Dark Energy Effective

The effective field theory of cosmic acceleration systematizes possible contributions to the action, accounting for both dark energy and modifications of gravity. Rather than making model dependent assumptions, it includes all terms, subject to the required symmetries, with four (seven) functions of time for the coefficients. These correspond respectively to the Horndeski and general beyond Horndeski class of theories. We address the question of whether this general systematization is actually effective, i.e. useful in revealing the nature of cosmic acceleration when compared with cosmological data. The answer is no and yes: there is no simple time dependence of the free functions—assumed forms in the literature are poor fits, but one can derive some general characteristics in early and late time limits. For example, we prove that the gravitational slip must restore to general relativity in the de Sitter limit of Horndeski theories, and why it doesn't more generally. We also clarify the relation between the tensor and scalar sectors, and its important relation to observations; in a real sense the expansion history H(z) or dark energy equation of state w(z) is 1/5 or less of the functional information! In addition we discuss the de Sitter, Horndeski, and decoupling limits of the theory utilizing Goldstone techniques.
Five-brane BPS states in heterotic M-theory

We present explicit methods for computing the discriminant curves and the associated Kodaira type fiber degeneracies of elliptically fibered Calabi-Yau threefolds. These methods are applied to a specific three-family, SU(5) grand unified theory of particle physics within the context of Heterotic M-Theory. It is demonstrated that there is always a region of moduli space where a bulk space five-brane is wrapped on a pure fiber in the Calabi-Yau threefold. Restricting the discussion to the smooth parts of the discriminant curve, we explore the properties of the N = 2 BPS supermultiplets that arise on the worldvolume of this five-brane due to the degeneration of the elliptic fiber. The associated degenerating M membranes are shown to project to string junctions in the base space. We use string junction techniques to explicitly compute the light BPS hyper- and vector multiplet spectrum for each Kodaira type fiber near the smooth part of the discriminant curve in the SU(5) GUT theory.
Generalizations of TASEP in Discrete and Continuous Inhomogeneous Space

We investigate a rich new class of exactly solvable particle systems generalizing the Totally Asymmetric Simple Exclusion Process (TASEP). Our particle systems can be thought of as new exactly solvable examples of tandem queues, directed first- or last-passage percolation models, or Robinson–Schensted–Knuth type systems with random input. One of the novel features of the particle systems is the presence of spatial inhomogeneity which can lead to the formation of traffic jams. For systems with special step-like initial data, we find explicit limit shapes, describe hydrodynamic evolution, and obtain asymptotic fluctuation results which put the systems into the Kardar–Parisi–Zhang universality class. At a critical scaling around a traffic jam in the continuous space TASEP, we observe deformations of the Tracy–Widom distribution and the extended Airy kernel, revealing the finer structure of this novel type of phase transitions. A homogeneous version of a discrete space system we consider is a one-parameter deformation of the geometric last-passage percolation, and we obtain extensions of the limit shape parabola and the corresponding asymptotic fluctuation results. The exact solvability and asymptotic behavior results are powered by a new nontrivial connection to Schur measures and processes.
Proportional Choosability of Complete Bipartite Graphs

Proportional choosability is a list analogue of equitable coloring that was introduced in 2019. The smallest k for which a graph G is proportionally k-choosable is the proportional choice number of G, and it is denoted $$\chi _{pc}(G)$$ . In the first ever paper on proportional choosability, it was shown that when $$2 \le n \le m$$ , $$\max \{ n + 1, 1 + \lceil m / 2 \rceil \} \le \chi _{pc}(K_{n,m}) \le n + m - 1$$ . In this note we improve on this result by showing that $$\max \{ n + 1, \lceil n / 2 \rceil + \lceil m / 2 \rceil \} \le \chi _{pc}(K_{n,m}) \le n + m -1- \lfloor m/3 \rfloor$$ . In the process, we prove some new lower bounds on the proportional choice number of complete multipartite graphs. We also present several interesting open questions.
SO(8) supergravity and the magic of machine learning

Using de Wit-Nicolai D = 4 $$ \mathcal{N} $$ = 8 SO(8) supergravity as an example, we show how modern Machine Learning software libraries such as Google’s TensorFlow can be employed to greatly simplify the analysis of high-dimensional scalar sectors of some M-Theory compactifications. We provide detailed information on the location, symmetries, and particle spectra and charges of 192 critical points on the scalar manifold of SO(8) supergravity, including one newly discovered $$ \mathcal{N} $$ = 1 vacuum with SO(3) residual symmetry, one new potentially stabilizable non-supersymmetric solution, and examples for “Galois conjugate pairs” of solutions, i.e. solution-pairs that share the same gauge group embedding into SO(8) and minimal polynomials for the cosmological constant. Where feasible, we give analytic expressions for solution coordinates and cosmological constants. As the authors’ aspiration is to present the discussion in a form that is accessible to both the Machine Learning and String Theory communities and allows adopting our methods towards the study of other models, we provide an introductory overview over the relevant Physics as well as Machine Learning concepts. This includes short pedagogical code examples. In particular, we show how to formulate a requirement for residual Supersymmetry as a Machine Learning loss function and effectively guide the numerical search towards supersymmetric critical points. Numerical investigations suggest that there are no further supersymmetric vacua beyond this newly discovered fifth solution.
Azimuthal jet flavor tomography with CUJET2.0 of nuclear collisions at RHIC and LHC

A perturbative QCD based jet tomographic Monte Carlo model, CUJET2.0, is presented to predict jet quenching observables in relativistic heavy ion collisions at RHIC/BNL and LHC/CERN energies. This model generalizes the DGLV theory of flavor dependent radiative energy loss by including multi-scale running strong coupling effects. It generalizes CUJET1.0 by computing jet path integrations though more realistic 2 + 1D transverse and longitudinally expanding viscous hydrodynamical fields contrained by fits to low p T flow data. The CUJET2.0 output depends on three control parameters, (α max , f E , f M ), corresponding to an assumed upper bound on the vacuum running coupling in the infrared and two chromo-electric and magnetic QGP screening mass scales (f E μ(T ), f M μ(T )) where μ(T ) is the 1-loop Debye mass. We compare numerical results as a function of α max for pure and deformed HTL dynamically enhanced scattering cases corresponding to (f E = 1, 2, f M = 0) to data of the nuclear modification factor, R (p T , ϕ; $$ \sqrt{s}, b $$ ) for jet fragment flavors f = π, D, B, e at $$ \sqrt{s} $$ = 0.2 − 2.76 ATeV c.m. energies per nucleon pair and with impact parameter b = 2.4, 7.5 fm. A χ 2 analysis is presented and shows that R data from RHIC and LHC are consistent with CUJET2.0 at the χ 2 /d.o.f < 2 level for α max = 0.23 − 0.30. The corresponding $$ \widehat{q} $$ (E jet , T )/T 3 effective jet transport coefficient field of this model is computed to facilitate comparison to other jet tomographic models in the literature. The predicted elliptic asymmetry, v 2(p T ; $$ \sqrt{s} $$ , b) is, however, found to significantly underestimated relative to RHIC and LHC data. We find the $$ {\chi}_{v_2}^2 $$ analysis shows that v 2 is very sensitive to allowing even as little as 10% variations of the path averaged α max along in and out of reaction plane paths.
A Framework For Optimizing Exoplanet Target Selection For The James Webb Space Telescope

The James Webb Space Telescope (JWST) will devote significant observing time to the study of exoplanets. It will not be serviceable as was the Hubble Space Telescope, and therefore the spacecraft/instruments will have a relatively limited life. It is important to get as much science as possible out of this limited observing time. We provide an analysis framework (including publicly released computational tools) that can be used to optimize lists of exoplanet targets for atmospheric characterization. Our tools take catalogs of planet detections, either simulated, or actual; categorize the targets by planet radius and equilibrium temperature; estimate planet masses; generate model spectra and simulated instrument spectra; perform a statistical analysis to determine if the instrument spectra can confirm an atmospheric detection; and finally, rank the targets within each category by observation time required. For a catalog of simulated Transiting Exoplanet Survey Satellite planet detections, we determine an optimal target ranking for the observing time available. Our results are generally consistent with other recent studies of JWST exoplanet target optimization. We show that assumptions about target planet atmospheric metallicity, instrument performance (especially the noise floor), and statistical detection threshold, can have a significant effect on target ranking. Over its full 10-year (fuel-limited) mission, JWST has the potential to increase the number of atmospheres characterized by transmission spectroscopy by an order of magnitude (from about 50 currently to between 400 and 500).
Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Unique lifting factorization results for group lifting structures are used to characterize the group-theoretic structure of two-channel linear phase FIR perfect reconstruction filter bank groups. For D-invariant, order-increasing group lifting structures, it is shown that the associated lifting cascade group C is isomorphic to the free product of the upper and lower triangular lifting matrix groups. Under the same hypotheses, the associated scaled lifting group S is the semidirect product of C by the diagonal gain scaling matrix group D. These results apply to the group lifting structures for the two principal classes of linear phase perfect reconstruction filter banks, the whole- and half-sample symmetric classes. Since the unimodular whole-sample symmetric class forms a group, W, that is in fact equal to its own scaled lifting group, W=SW, the results of this paper characterize the group-theoretic structure of W up to isomorphism. Although the half-sample symmetric class ħ does not form a group, it can be partitioned into cosets of its lifting cascade group, Cħ, or, alternatively, into cosets of its scaled lifting group, Sħ. Homomorphic comparisons reveal that scaled lifting groups covered by the results in this paper have a structure analogous to a “noncommutative vector space”.
Erratum to "Full and reduced C*-coactions". Math. Proc. Camb. Phil. Soc. 116 (1994), 435--450

Proposition 2ċ5 of [ 5 ] states that a full coaction of a locally compact group on a C *-algebra is nondegenerate if and only if its normalisation is. Unfortunately, the proof there only addresses the forward implication, and we have not been able to find a proof of the opposite implication. This issue is important because the theory of crossed-product duality for coactions requires implicitly that the coactions involved be nondegenerate. Moreover, each type of coaction — full, reduced, normal, maximal, and (most recently) exotic — has its own distinctive properties with respect to duality, making it crucial to be able to convert from one to the other without losing nondegeneracy.
The Mathematics of Taffy Pullers

We describe a number of devices for pulling candy, called taffy pullers,that are related to pseudo-Anosov maps of punctured spheres. Though the mathematical connection has long been known for the two most common taffy puller models, we unearth a rich variety of early designs from the patent literature, and introduce a new one.
Links with finite n–quandles

Associated to every oriented link L in the 3–sphere is its fundamental quandle and, for each n > 1, there is a certain quotient of the fundamental quandle called the n–quandle of the link. We prove a conjecture of Przytycki which asserts that the n–quandle of an oriented link L in the 3–sphere is finite if and only if the fundamental group of the n–fold cyclic branched cover of the 3–sphere, branched over L, is finite. We do this by extending into the setting of n–quandles, Joyce’s result that the fundamental quandle of a knot is isomorphic to a quandle whose elements are the cosets of the peripheral subgroup of the knot group. In addition to proving the conjecture, this relationship allows us to use the well-known Todd–Coxeter process to both enumerate the elements and find a multiplication table of a finite n–quandle of a link. We conclude the paper by using Dunbar’s classification of spherical 3–orbifolds to determine all links in the 3–sphere with a finite n–quandle for some n.
Using isomorphic problems to learn introductory physics

In this study, we examine introductory physics students' ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. Three hundred sixty-two students from a calculus-based and an algebra-based introductory physics course were given a quiz in the recitation in which they had to first learn from a solved problem provided and take advantage of what they learned from it to solve another problem (which we call the quiz problem) which was isomorphic. Previous research suggests that the multiple-concept quiz problem is challenging for introductory students. Students in different recitation classes received different interventions in order to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. We also conducted think-aloud interviews with four introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. We found that most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem. However, they were not necessarily able to apply the principles correctly. Research suggests that more scaffolding is needed to help students in applying these principles appropriately. We outline a few possible strategies for future investigation.
Reinforcement Learning for Improving Agent Design.

In many reinforcement learning tasks, the goal is to learn a policy to manipulate an agent, whose design is fixed, to maximize some notion of cumulative reward. The design of the agent's physical s...
Associative3D: Volumetric Reconstruction from Sparse Views

This paper studies the problem of 3D volumetric reconstruction from two views of a scene with an unknown camera. While seemingly easy for humans, this problem poses many challenges for computers since it requires simultaneously reconstructing objects in the two views while also figuring out their relationship. We propose a new approach that estimates reconstructions, distributions over the camera/object and camera/camera transformations, as well as an inter-view object affinity matrix. This information is then jointly reasoned over to produce the most likely explanation of the scene. We train and test our approach on a dataset of indoor scenes, and rigorously evaluate the merits of our joint reasoning approach. Our experiments show that it is able to recover reasonable scenes from sparse views, while the problem is still challenging. Project site: https://jasonqsy.github.io/Associative3D.
Snx14 proximity labeling reveals a role in saturated fatty acid metabolism and ER homeostasis defective in SCAR20 disease.

Fatty acids (FAs) are central cellular metabolites that contribute to lipid synthesis, and can be stored or harvested for metabolic energy. Dysregulation in FA processing and storage causes toxic FA accumulation or altered membrane compositions and contributes to metabolic and neurological disorders. Saturated lipids are particularly detrimental to cells, but how lipid saturation levels are maintained remains poorly understood. Here, we identify the cerebellar ataxia spinocerebellar ataxia, autosomal recessive 20 (SCAR20)-associated protein Snx14, an endoplasmic reticulum (ER)–lipid droplet (LD) tethering protein, as a factor required to maintain the lipid saturation balance of cell membranes. We show that following saturated FA (SFA) treatment, the ER integrity of SNX14KO cells is compromised, and both SNX14KO cells and SCAR20 disease patient-derived cells are hypersensitive to SFA-mediated lipotoxic cell death. Using APEX2-based proximity labeling, we reveal the protein composition of Snx14-associated ER–LD contacts and define a functional interaction between Snx14 and Δ-9 FA desaturase SCD1. Lipidomic profiling reveals that SNX14KO cells increase membrane lipid saturation following exposure to palmitate, phenocopying cells with perturbed SCD1 activity. In line with this, SNX14KO cells manifest delayed FA processing and lipotoxicity, which can be rescued by SCD1 overexpression. Altogether, these mechanistic insights reveal a role for Snx14 in FA and ER homeostasis, defects in which may underlie the neuropathology of SCAR20.
External funding and emergent technology inputs

The research and development (R&D) process is critical to a firm’s competitive advantage and often requires external funding. Yet, we know little about how different types of investors respond to the cash needs of established R&D intensive firms nor about how external financial analysts influence those decisions. We address these gaps by examining how a firm’s patenting activity affects its ability to raise cash. We distinguish the motivations of two investor groups: open-market and alliance partners. We focus on how patents based on emergent technologies impact two types of investors and their willingness to fund the R&D process. We develop theory and test our hypotheses using data from publicly traded biopharmaceutical firms by drawing upon knowledge-based view, alliance, and investment theories. We find evidence that patents built upon emergent technologies are viewed differently by the two types of investors. We find open market investors were less likely to invest in emergent technologies and invested less when they did. Conversely, alliance partner investors would be more appreciative of the opportunities new technology inputs present, thus, more likely to invest in firms using emergent technologies and invest more.
Remarks on Jones Slopes and Surfaces of Knots

We show that the strong slope conjecture implies that the degrees of the colored Jones knot polynomials detect the figure 8 knot. Furthermore, we propose a characterization of alternating knots in terms of the Jones period and the degree span of the colored Jones polynomial
Bernoulli Factories and Black-box Reductions in Mechanism Design

We provide a polynomial time reduction from Bayesian incentive compatible mechanism design to Bayesian algorithm design for welfare maximization problems. Unlike prior results, our reduction achieves exact incentive compatibility for problems with multi-dimensional and continuous type spaces. The key technical barrier preventing exact incentive compatibility in prior black-box reductions is that repairing violations of incentive constraints requires understanding the distribution of the mechanism’s output, which is typically #P-hard to compute. Reductions that instead estimate the output distribution by sampling inevitably suffer from sampling error, which typically precludes exact incentive compatibility. We overcome this barrier by employing and generalizing the computational model in the literature on Bernoulli Factories. In a Bernoulli factory problem, one is given a function mapping the bias of an “input coin” to that of an “output coin,” and the challenge is to efficiently simulate the output coin given only sample access to the input coin. This is the key ingredient in designing an incentive compatible mechanism for bipartite matching, which can be used to make the approximately incentive compatible reduction of Hartline et al. [18] exactly incentive compatible.
The Cost of Denied Observation in Multiagent Submodular Optimization

A popular formalism for multiagent control applies tools from game theory, casting a multiagent decision problem as a cooperation-style game in which individual agents make local choices to optimize their own local utility functions in response to the observable choices made by other agents. When the system-level objective is submodular maximization, it is known that if every agent can observe the action choice of all other agents, then all Nash equilibria of a large class of resulting games are within a factor of 2 of optimal; that is, the price of anarchy is 1/2. However, little is known if agents cannot observe the action choices of other relevant agents. To study this, we extend the standard game-theoretic model to one in which a subset of agents either become blind (unable to observe others’ choices) or isolated (blind, and also invisible to other agents), and we prove exact expressions for the price of anarchy as a function of the number of compromised agents. When k agents are compromised (in any combination of blind or isolated), we show that the price of anarchy for a large class of utility functions is exactly 1/(2 + k). We then show that if agents use marginal-cost utility functions and at least 1 of the compromised agents is blind (rather than isolated), the price of anarchy improves to 1/(1 + k). We also provide simulation results demonstrating the effects of these observation denials in a dynamic setting.
On the Indivisibility of Rights: Truth Commissions, Reparations, and the Right to Development

While academics debate the ranking of rights, information from the field demonstrates their indivisibility. This Article explores how truth commissions provide rich documentation of the interrelation between violations of Civil and Political Rights (CPR) and Economic, Social and Cultural Rights (ESCR), using Peru’s Truth and Reconciliation Commission (TRC) as an example. The TRC’s findings show how social and economic inequalities contributed to the eruption of political violence, which further exacerbated these conditions. This revelation challenged the TRC to develop a reparation plan that adequately responded to the needs of victim-survivors, while maintaining a causal link with damage caused by the conflict. Ultimately, the TRC focused narrowly on repairing damage caused by CPR violations. Yet now, almost four years later, the government confuses development with traditional reparation measures, generating criticism. The author proposes that Peru’s post-conflict recovery may need to accept the overlap between reparations and development to improve the “well being” of its intended beneficiaries.
From SARS to Ebola: Legal and Ethical Considerations for Modern Quarantine

Quarantine remains an important part of the strategy for containing infectious diseases, especially when there is no vaccine or demonstrably effective treatment. Experience with SARS and, more recently, Ebola indicate that quarantine is fraught with ethical challenges. In the United States, legislation authorizing quarantine has been enacted in every state, and these laws have been upheld by the Supreme Court. The problems have been in identifying when quarantine is necessary and in implementation. The following ethical principles should guide public health officials in deciding whether and how to impose a quarantine: (1) necessity, effectiveness, and scientific rationale; (2) proportionality and least infringement; (3) humane supportive services; and (4) public justification.
Supply Chain Game Changers—Mega, Nano, and Virtual Trends—And Forces That Impede Supply Chain Design (i.e., Building a Winning Team)

Strategic systems design is essential to structuring and governing a supply chain for competitive advantage. To effectively co-create value, decision makers must manage the three rights of supply chain design: right players, right roles, and right relationships. Doing this well requires managers discern how the unwritten competitive rules are changing as well as determine firm readiness to compete. As part of this analysis, we briefly explore five emerging “game changers” that represent potential supply chain design inflection points: (1) Big Data and predictive analytics, (2) additive manufacturing, (3) autonomous vehicles, (4) materials science, and (5) borderless supply chains. We also consider four forces that impede transformation to higher levels of value co-creation: (1) supply chain security, (2) failed change management, (3) lack of trust as a governance mechanism, and (4) poor understanding of the “luxury” nature of corporate social responsibility initiatives. How well managers address sociostructural and sociotechnical issues will determine firm survivability and success.
Unwritten Constitutionalism in Canada: Where Do Things Stand

Written in reply to Elizabeth Edinger's 2001 article "The Tobacco Damages and Health Care Costs Recovery Act: JTI-Macdonald Corp. v. British Columbia (Attorney General)", this article situates the British Columbia Court of Appeal's decision in JTI within the broader context of unwritten constitutionalism in Canada, and supports Edinger's proposition that JTI was wrongly decided and should have been appealed on the narrow issue of extraterritoriality. It considers how the Reference re: Secession of Quebec introduced unwritten constitutionalism into the Canadian constitutional agenda. It then explores how the Provincial Judges References laid the doctrinal groundwork for the Secession Reference's departure from a positivist reliance on textuality within Canadian constitutionalism, and itself emerged from three earlier sets of cases that dealt with unwritten constitutionalism. The author concludes that although unwritten constitutionalism poses challenges to a democratic system of government, but also extends an invitation to the Supreme Court of Canada to meet its responsibility to openly and transparently interpret constitutional texts in accordance with unwritten democratic principles. The author holds that unwritten constitutionalism ultimately invites a reinvigorated interpretation of the written constitution.
Atomistic congestion tolls at concentrated airports? Seeking a unified view in the internalization debate

Abstract The goal of this paper is to bring some unity to the theoretical side of the debate on internalization of airport congestion by showing that all the literature's theoretical results can be derived within one simple and unified framework. The analysis starts by replicating the results of Brueckner [Brueckner, J.K., 2002. Airport congestion when carriers have market power. American Economic Review 92, 1357–1375], who showed that, because airlines behaving in Cournot fashion internalize congestion, they should be charged low congestion tolls. The analysis then validates the findings of Daniel [Daniel, J.I., 1995. Congestion pricing and capacity of large hub airports: A bottleneck model with stochastic queues. Econometrica 63, 327–370], who argued that larger atomistic tolls are required in a model where a Stackelberg leader interacts with competitive fringe airlines. However, it is shown that this result only holds approximately when the carriers' outputs are imperfect substitutes.
Tackling Employment Discrimination with ADR: Does Mediation Offer a Shield for the Haves or Real Opportunity for the Have-Nots

This paper explores the benefits of using mediation in addressing employment discrimination disputes. It highlights the difficulties for those who expect too much out of mediation by expecting it to transform relations while exposing concerns with those who limit mediation's potential by supporting mythical notions about mediators being neutral. The paper suggests that employers develop comprehensive conflict resolution systems and include mediation as a process that is case-specific and focused on the needs of all parties and not the needs of the mediator.
Who's Afraid of WikiLeaks? Missed Opportunities in Political Science Research

Leaked information, such as WikiLeaks’ Cablegate, constitutes a unique and valuable data source for researchers interested in a wide variety of policy-oriented topics. Yet political scientists have avoided using leaked information in their research. This article argues that we can and should use leaked information as a data source in scholarly research. First, the methodological, ethical, and legal challenges related to the use of leaked information in research have been considered, concluding that none of these present serious obstacles. Second, how political scientists can use leaked information to generate novel and unique insights concerning political phenomena using a variety of quantitative and qualitative methods have been shown. Specifically, how leaked documents reveal important details concerning the Trans-Pacific Partnership negotiations, and how leaked diplomatic cables highlight a significant disparity between the U.S. government's public attitude toward traditional knowledge and its private behavior have been demonstrated.
Do Actions Speak Louder Than Words? An Experimental Comparison of Observation and Cheap Talk☆

Abstract This paper reports results from an experiment designed to compare cheap talk and observation of past actions. We consider three games and explain why cheap talk or observation is likely to be more effective for achieving good outcomes in each game. We find that both cheap talk and observation make cooperation and coordination more likely and increase payoffs, relative to our control treatment. The relative success of cheap talk versus observation depends on the game, in accordance with our predictions. We also find that players' signals are informative, and that signal receivers condition their actions on the signal they receive. Journal of Economic Literature Classification Numbers: C72, D83.
Collateral and Capital Structure

Abstract We develop a dynamic model of investment, capital structure, leasing, and risk management based on firms' need to collateralize promises to pay with tangible assets. Both financing and risk management involve promises to pay subject to collateral constraints. Leasing is strongly collateralized costly financing and permits greater leverage. More constrained firms hedge less and lease more, both cross-sectionally and dynamically. Mature firms suffering adverse cash flow shocks may cut risk management and sell and lease back assets. Persistence of productivity reduces the benefits to hedging low cash flows and can lead firms not to hedge at all.
Defining neighborhood boundaries: Are census tracts obsolete?

Abstract Residential neighborhoods are defined as convex geographical areas containing similar populations and roughly homogeneous housing markets. Neighborhoods are relevant largely because confidentiality requires spatial aggregation of data collected at the household level. A hedonic model using individual sales transactions and their street addresses is combined with CART (Classification and Regression Trees) to define the optimal number of neighborhoods and to place neighborhood boundaries in one Connecticut town. There are about half the number of CART neighborhoods than there are census tracts. Moreover, the CART boundaries typically run behind the houses rather than down the middle of the street, and they reduce residual variation. The CART model is important to the submarkets literature, which aggregates neighborhoods into larger homogeneous markets. Moreover, anisotropic spatial autocorrelation can be modeled with CART neighborhoods.
Institutions and growth: A GMM/IV Panel VAR approach

Abstract Both sides of the institutions and growth debate have resorted largely to microeconometric techniques in testing hypotheses. In this paper, I build a panel structural vector autoregression (SVAR) model for a short panel of 119 countries over 10 years and find support for the institutions hypothesis. Controlling for individual fixed effects, I find that exogenous shocks to a proxy for institutional quality have a positive and statistically significant effect on GDP per capita. On average, a 1% shock in institutional quality leads to a peak 1.7% increase in GDP per capita after six years. Results are robust to using a different proxy for institutional quality. There are different dynamics for advanced economies and developing countries. This suggests diminishing returns to institutional quality improvements.
Response of the equilibrium real exchange rate to real disturbances in developing countries

Abstract Using a simple dependent-economy framework, this paper outlines the links between the equilibrium real exchange rate and some of its fundamental exogenous determinants, mainly terms of trade movements and commercial policy changes. Drawing on existing studies of trade flows in developing countries, it is possible to derive plausible quantitative ranges for the response of the equilibrium real exchange rate to both external and policy-induced shocks. The results should be particularly relevant in designing real exchange rate targets and rules that allow for movements in the equilibrium real exchange rate in response to various shocks.
A New Product for the State Corporation Law Market: Audit Committee Certifications

Follow this and additional works at: http://lawdigitalcommons.bc.edu/lsfp Part of the Administrative Law Commons, Agency Commons, Corporation and Enterprise Law Commons, Economics Commons, Ethics and Professional Responsibility Commons, Labor and Employment Law Commons, Law and Economics Commons, Law and Society Commons, Legal History, Theory and Process Commons, Legal Writing and Research Commons, Litigation Commons, Organizations Commons, Partnerships Commons, Politics Commons, Secured Transactions Commons, and the State and Local Government Law Commons
Detecting Opportunistic Special Items

The frequency of special items has increased dramatically over time, offering a convenient conduit for the inappropriate classification of past, present, and future recurring expenses as nonrecurri...
Investing for retirement: The moderating effect of fund assortment size on the 1/n heuristic

Abstract Does the number of funds offered in a defined contribution plan affect how many funds consumers choose to invest in or how they spread dollars across the funds they choose? Across three experiments and the analysis of defined contribution plan data, the authors explore these issues by examining investors' tendency to engage in the 1/n heuristic— that is, allocating their dollars evenly across all available investment options. The authors decompose this heuristic into its two underlying behavioral dimensions: the tendency to invest in all available funds (which they label “1/n#”) and the tendency to spread the invested dollars evenly across chosen funds (which they label “1/n$”). The authors argue that choosing from larger fund assortments taxes investors' cognitive resources, which leads to more simplified diversification strategies. They find that increasing the fund assortment size decreases the tendency to invest in all available funds (1/n#) but increases the tendency to spread the invested d...
Belief in a Just World and Redistributive Politics

International surveys reveal wide differences between the views held in different countries concerning the causes of wealth or poverty and the extent to which people are responsible for their own fate. At the same time, social ethnographies and experiments by psychologists demonstrate individuals' recurrent struggle with cognitive dissonance as they seek to maintain, and pass on to their children, a view of the world where effort ultimately pays off and everyone gets their just deserts. This paper offers a model that helps explain: i) why most people feel such a need to believe in a “just world”; ii) why this need, and therefore the prevalence of the belief, varies considerably across countries; iii) the implications of this phenomenon for international differences in political ideology, levels of redistribution, labor supply, aggregate income, and popular perceptions of the poor. The model shows in particular how complementarities arise endogenously between individuals' desired beliefs or ideological choices, resulting in two equilibria. A first, “American” equilibrium is characterized by a high prevalence of just-world beliefs among the population and relatively laissez-faire policies. The other, “European” equilibrium is characterized by more pessimism about the role of effort in economic outcomes and a more extensive welfare state. More generally, the paper develops a theory of collective beliefs and motivated cognitions, including those concerning “money” (consumption) and happiness, as well as religion.
Japanese Corporate Governance: The Hidden Problems of the Corporate Law and Their Solutions

It has long been said that the Japanese corporate governance does not pay sufficient attention to shareholders as the owners of the corporation. An yet, despite this seeming lack of shareholder ownership, Japanese firms have performed quite well until recently. This paper seeks to solve this conundrum by developing the Company Community concept as a positive model of the Japanese corporate governance. This model is used to illustrate how the Japanese system of corporate governance solves the hidden problems of the corporate law. These hidden problems of corporate law are common to all developed economies and consist of the dual problems of balancing between monitoring and autonomy of management and balancing between money capital and human capital. The company community concept solves these problems through an intricate system of monitoring consisting of three levels. The first level is the in-house monitoring by core employees who are quasi-residual claimants and monitor management as a participant in the Community. The second level is the monitoring by cross-shareholders in the firm, the main bank in particular. Cross-shareholding also has the effect of stabilizing the management position against outside control. The third level is the monitoring by exit of the outside shareholders. These multiple levels of monitoring have the effect of stabilizing management yet upholding shareholder ownership as the end game norm.
Optimal contracting in networks

Abstract We study optimal contracting between a firm selling a divisible good that exhibits positive externality and a group of agents in a social network. The extent of externality that each agent receives from the consumption of neighboring agents is privately held and is unknown to the firm. By explicitly characterizing the optimal multilateral contract, we demonstrate how inefficiency in an agent's trade propagates through the network and creates unequal and network-dependent downward distortion in other agents' trades. Furthermore, we describe bilateral contracts (non-linear pricing schemes) and characterize their explicit dependence on the network structure. We show that the firm will benefit from uncertainty in an agent's valuation of other agents' externality. We describe the profit gap between multilateral and bilateral contracts and analyze the consequences of the explicit dependence of the contracts on network structure. When the network is balanced in terms of homogeneity of agents' influence, network structure has no impact on the firm's profit for bilateral contracts. On the other hand, when the influences are heterogeneous with high dispersion (as in core-periphery networks) the restriction to bilateral contracts can result in profit losses that grow unbounded with the size of networks.
Choosing a Text for the Family Law Curriculum of the Twenty-First Century

This article describes the Family Law Education Reform (FLER) Project Report and provides recommendations as to how a family law professor should select a course textbook. I note that the FLER Report focuses on the importance of new lawyers being sensitive to gender, race, and class and discuss how a textbook focusing on policy, practice problems, and collaborative skills will satisfy the FLER project’s recommendations.
Mutual Funds and Stock and Bond Market Stability

The unprecedented growth of mutual funds has raised questions about the impact of mutual fund flows on stock and bond prices. Many believe that the equity bull market of the 1990s is attributable to the huge flows of funds into equity mutual funds during this period and that a withdrawal of those funds could send stock prices plummeting. This article investigates the relationship between aggregate monthly mutual fund flows (sales, redemptions, and net sales) and stock and bond monthly returns during a 30-year period beginning January 1961 utilizing Granger causality and instrumental variables analysis. With one exception, flows into stock and bond funds have not affected either stock and bond returns. The exception is 1971–1981, when widespread redemptions from equity mutual funds significantly depressed stock returns. In contrast, the magnitude of flows into both stock and bond funds are affected significantly by stock and bond returns.
Presidential values in parliamentary democracies

Constitutional theory has long held that the separation of powers is unique to presidential systems and incompatible with parliamentary ones. This conventional wisdom has hardened over the years with the proliferation of scholarship debating the merits of presidential or parliamentary systems for emerging democracies or reconstructed states.1 Yet what remains unexplored within this conventional wisdom in constitutional design is whether the democratic virtues of the separation of powers are achievable in both presidential and parliamentary systems. The answer, I believe, is yes. For despite its prevalence in the community of nations, the presidential separation of powers is neither constitutive nor descriptive of modern constitutionalism. Indeed, many constitutional democracies contravene the underlying philosophy of separated governmental powers insofar as they exhibit the very opposite of the separation of powers: the fusion of governmental powers.2 These regimes tend predominantly to be
Occupational and Job Mobility in the US

We propose a new methodology to measure worker mobility across occupations and jobs in the US, building on the limited longitudinal dimension of monthly CPS data. For the period 1979–2006, we find that about 3.5% of male workers employed in two consecutive months report different three-digit occupations. This rate is procyclical, mildly rising in the 1980s and falling after 1995. We also revise upward current estimates of aggregate job-to-job mobility since 1994, from 2.7% to 3.2% of employment per month. Despite extreme similarity of average levels and time-series behavior, occupational and job mobility are only weakly correlated.
Is There a Vatican School for Competition Policy

This Article examines whether the Catholic Church’s social teaching has something to tell antitrust scholars and masters of competition policy. Although papal encyclical letters and other documents are not meant to provide an analytical framework giving clear answers to complex competition questions, this does not mean that these thoughts cannot benefit businessmen, scholars, and policy makers. The Vatican teaching helps us remember that business and morality do not belong to two different worlds, and that markets should serve the whole Man. It acknowledges the positive role of free markets, that is, the exercise of economic freedom as being an important part of human dignity, yet warns that competition can be preserved only if it is curbed both by moral and statutory rules. It is certainly not easy to find a balance between the commandments to “love your neighbor” and “not collect treasure on earth.” I argue that either antitrust law or other forms of selfor government regulation should prohibit market conduct that undermines business virtues.
Fourth Amendment Fiduciaries

I. THE DOCTRINAL STORY 4 A. EXPOSURE 6 B. MISPLACED TRUST 8 C. EXPANDING THE HORIZON OF PROTECTION 11 1. Doctors 11 2. Hotel Managers 17 D. BEYOND STATE ACTION 21
The same yet different: Worker reports on labour practices and outcomes in a single firm across countries

Abstract This paper examines cross-country differences in labour policies and practices and employee performance and attitudes toward work from a sample of nearly 30,000 employees in a large multinational manufacturing firm. The analysis shows: 1) large establishment and country differences in work practices, performance, and attitudes toward work across countries; 2) qualitatively similar responses of workers to work practices across countries; 3) a strong link between the establishment average of employee reports on the quality of labour-management relations and establishment average measures of employee performance 4) a positive relation between average employee performance and average employee-management relations at the country level, but no relation between country level performance in the firm and measures of the extent of national labour regulations or practices.
China After the Reform Era

China’s reform era is ending. Core factors that characterized it—political stability, ideological openness, and rapid economic growth—are unraveling. In part, this is the result of Beijing’s steadfast refusal to contemplate fundamental political reform. Since the early 1990s, this has fueled the rise of entrenched interests within the Communist Party itself. It has also contributed to the systematic underdevelopment of institutions of governance among state and society at large. Now, to address looming problems confronting the nation, Chinese leaders are progressively cannibalizing institutional norms and practices that have formed the bedrock of the regime’s stability in the post-Mao era.