cssi/SciSciGPT-SciSciNet huggingface dataset:
Multifunctional on-chip storage at telecommunication wavelength for quantum networks

Quantum networks will enable a variety of applications, from secure communication and precision measurements to distributed quantum computing. Storing photonic qubits and controlling their frequency, bandwidth, and retrieval time are important functionalities in future optical quantum networks. Here we demonstrate these functions using an ensemble of erbium ions in yttrium orthosilicate coupled to a silicon photonic resonator and controlled via on-chip electrodes. Light in the telecommunication C-band is stored, manipulated, and retrieved using a dynamic atomic frequency comb protocol controlled by linear DC Stark shifts of the ion ensemble’s transition frequencies. We demonstrate memory time control in a digital fashion in increments of 50 ns, frequency shifting by more than a pulse width (±39MHz), and a bandwidth increase by a factor of 3, from 6 to 18 MHz. Using on-chip electrodes, electric fields as high as 3 kV/cm were achieved with a low applied bias of 5 V, making this an appealing platform for rare-earth ions, which experience Stark shifts of the order of 10 kHz/(V/cm).
Delayed onset and the transition to late time growth in viscous fingering

The characteristic heavily branched patterns that result from viscous fingering instability are due to highly nonlinear growth of the fingers at late time. Here, the existence of an onset length scale associated with the transition between linear and nonlinear growth is revealed. Remarkably, by measuring this onset point, features of the patterns that form well into the nonlinear regime can be predicted. Existing theoretical work is not sufficient to understand this length scale, especially for miscible fluids where the fluid structure within the small scale of the gap becomes important.
Spontaneous breaking of U(1) symmetry in coupled complex SYK models

As shown in [1], two copies of the large N Majorana SYK model can produce spontaneous breaking of a Z2 symmetry when they are coupled by appropriate quartic terms. In this paper we similarly study two copies of the complex SYK model coupled by a quartic term preserving the U(1) × U(1) symmetry. We also present a tensor counterpart of this coupled model. When the coefficient α of the quartic term lies in a certain range, the coupled large N theory is nearly conformal. We calculate the scaling dimensions of fermion bilinear operators as functions of α. We show that the operator $$ {c}_{1i}^{\dagger }{c}_{2i} $$ , which is charged under the axial U(1) symmetry, acquires a complex dimension outside of the line of fixed points. We derive the large N Dyson-Schwinger equations and show that, outside the fixed line, this U(1) symmetry is spontaneously broken at low temperatures because this operator acquires an expectation value. We support these findings by exact diagonalizations extrapolated to large N.
On selecting a probabilistic classifier for appointment no-show prediction

Abstract Appointment no-shows are disruptive to healthcare clinics, and may increase patient waiting time and clinic overtime, resulting in increased clinic costs. Appointment scheduling models typically mitigate the negative effects of no-shows through appointment overbooking. Recent work has proposed a predictive overbooking framework, where a probabilisitic classifier predicts the no-show probability of individual appointment requests, and a scheduling algorithm uses those predictions to optimally schedule appointments. Because predicting no-shows is typically an imbalanced classification problem, the preferred classifier is often chosen based upon the area under the receiver operator characteristic curve (AUC), which is a commonly used metric for many other imbalanced classification problems. Contrary to intuition, in this paper we show that employing the AUC to select a classifier results in significantly lower schedule efficiency than using other metrics such as Log Loss or Brier Score. Our computational experiments, validated on large real-world appointment data, suggest that by using Log Loss or Brier Score instead of AUC, practitioners can improve the schedule quality by 3–7%.
Tax revenue and (or?) trade liberalization

Abstract With the public finances of many developing and emerging market countries still heavily dependent on trade tax revenues, further trade liberalization may be hindered unless they are able to develop alternative sources of revenue. Against a background of, and to inform, heightened theoretical controversy as to the appropriate balance between trade and other taxes (not least the VAT), this paper uses panel data for 117 countries over 32 years—cleaned for a variety of problems in standard data sources—to address a central question of fact: Have countries recovered from domestic taxes the revenues they have lost from past episodes of trade liberalization? For high income countries, the answer is clearly ‘yes.’ For middle income countries, there are robust signs of strong replacement both concurrently with the revenue loss and—essentially dollar-for-dollar—in the long run. Signs of significant recovery by low income countries are flimsier, however, and their experiences appear to have varied widely. The picture that emerges for low income countries is thus that replacement has been (and become) higher than previous studies have suggested, but sufficiently incomplete in many cases to give cause for concern.
Circuit and synaptic organization of forebrain-to-midbrain pathways that promote and suppress vocalization

Animals vocalize only in certain behavioral contexts, but the circuits and synapses through which forebrain neurons trigger or suppress vocalization remain unknown. Here, we used transsynaptic tracing to identify two populations of inhibitory neurons that lie upstream of neurons in the periaqueductal gray (PAG) that gate the production of ultrasonic vocalizations (USVs) in mice (i.e. PAG-USV neurons). Activating PAG-projecting neurons in the preoptic area of the hypothalamus (POAPAG neurons) elicited USV production in the absence of social cues. In contrast, activating PAG-projecting neurons in the central-medial boundary zone of the amygdala (AmgC/M-PAG neurons) transiently suppressed USV production without disrupting non-vocal social behavior. Optogenetics-assisted circuit mapping in brain slices revealed that POAPAG neurons directly inhibit PAG interneurons, which in turn inhibit PAG-USV neurons, whereas AmgC/M-PAG neurons directly inhibit PAG-USV neurons. These experiments identify two major forebrain inputs to the PAG that trigger and suppress vocalization, respectively, while also establishing the synaptic mechanisms through which these neurons exert opposing behavioral effects.
Crosstalk and ultrasensitivity in protein degradation pathways.

Protein turnover is vital to cellular homeostasis. Many proteins are degraded efficiently only after they have been post-translationally “tagged” with a polyubiquitin chain. Ubiquitylation is a form of Post-Translational Modification (PTM): addition of a ubiquitin to the chain is catalyzed by E3 ligases, and removal of ubiquitin is catalyzed by a De-UBiquitylating enzyme (DUB). Nearly four decades ago, Goldbeter and Koshland discovered that reversible PTM cycles function like on-off switches when the substrates are at saturating concentrations. Although this finding has had profound implications for the understanding of switch-like behavior in biochemical networks, the general behavior of PTM cycles subject to synthesis and degradation has not been studied. Using a mathematical modeling approach, we found that simply introducing protein turnover to a standard modification cycle has profound effects, including significantly reducing the switch-like nature of the response. Our findings suggest that many classic results on PTM cycles may not hold in vivo where protein turnover is ubiquitous. We also found that proteins sharing an E3 ligase can have closely related changes in their expression levels. These results imply that it may be difficult to interpret experimental results obtained from either overexpressing or knocking down protein levels, since changes in protein expression can be coupled via E3 ligase crosstalk. Understanding crosstalk and competition for E3 ligases will be key in ultimately developing a global picture of protein homeostasis.
Macrophages Respond Rapidly to Ototoxic Injury of Lateral Line Hair Cells but Are Not Required for Hair Cell Regeneration

The sensory organs of the inner ear contain resident populations of macrophages, which are recruited to sites of cellular injury. Such macrophages are known to phagocytose the debris of dying cells but the full role of macrophages in otic pathology is not understood. Lateral line neuromasts of zebrafish contain hair cells that are nearly identical to those in the inner ear, and the optical clarity of larval zebrafish permits direct imaging of cellular interactions. In this study, we used larval zebrafish to characterize the response of macrophages to ototoxic injury of lateral line hair cells. Macrophages migrated into neuromasts within 20 min of exposure to the ototoxic antibiotic neomycin. The number of macrophages in the near vicinity of injured neuromasts was similar to that observed near uninjured neuromasts, suggesting that this early inflammatory response was mediated by "local" macrophages. Upon entering injured neuromasts, macrophages actively phagocytosed hair cell debris. The injury-evoked migration of macrophages was significantly reduced by inhibition of Src-family kinases. Using chemical-genetic ablation of macrophages before the ototoxic injury, we also examined whether macrophages were essential for the initiation of hair cell regeneration. Results revealed only minor differences in hair cell recovery in macrophage-depleted vs. control fish, suggesting that macrophages are not essential for the regeneration of lateral line hair cells.
Counting finite index subrings of $\mathbb Z^n$

We count subrings of small index of $\mathbb{Z}^n$, where the addition and multiplication are defined componentwise. Let $f_n(k)$ denote the number of subrings of index $k$. For any $n$, we give a formula for this quantity for all integers $k$ that are not divisible by a 9th power of a prime, extending a result of Liu.
Strong Structural Controllability of Diffusively Coupled Networks: Comparison of Bounds Based on Distances and Zero Forcing

We study the strong structural controllability (SSC) of diffusively coupled networks, where the external control inputs are injected to only some nodes, namely the leaders. For such systems, one measure of controllability is the dimension of strong structurally controllable subspace, which is equal to the smallest possible rank of controllability matrix under admissible (positive) coupling weights. In this paper, we compare two tight lower bounds on the dimension of strong structurally controllable subspace: one based on the distances of followers to leaders, and the other based on the graph coloring process known as zero forcing. We show that the distance-based lower bound is usually better than the zero-forcing-based bound when the leaders do not constitute a zero-forcing set. On the other hand, we also show that any set of leaders that can be shown to achieve complete SSC via the distance-based bound is necessarily a zero-forcing set. Furthermore, we present a novel bound based on the combination of these two approaches, which is always at least as good as, and in some cases strictly greater than, the maximum of the two bounds. Finally, we present some numerical results to compare the bounds on various graphs.
How much is an incoming message worth? Estimating the call externality

Abstract A feature of electronic communication markets is that a consumer's decision to join or use a communications network can generate two effects on other users of the network: a network externality and a call externality. The former effect is defined as the benefit that users receive when a new subscriber joins the network (an expanded customer base can now be reached). The existence and magnitude of this effect is important from both theoretical and policy points of view. As a consequence, its empirical importance in various network markets has been documented in the literature. A call externality is defined as the benefit that a consumer derives when receiving a message (e.g. call) from another user, and it plays a crucial role both in the equilibrium predictions of theories of network competition and in the results of recent empirical work; however, as opposed to the network externality, no attempt has been made to quantify its empirical importance. In this paper I report results of a study designed to elicit and estimate the call externality. The data were generated using a stated-preference choice experiment designed to match theory and several characteristics of the mobile industry in Ecuador. To enhance the external validity of the results, the choice experiment was administered to over 2,500 individuals using 492 different internet-equipped government-run locations throughout the country. I find that call externalities are quite important in this market, but that their intensity depends heavily on the type of call (on-net v. off-net) as well as on the type of user (pre-paid v. post-paid). The call externality parameter for on-net calls is estimated at 0.67, while the significance of the call externality for off-net calls is significantly smaller (economically and statistically). Further, I find that the existence of call externalities in the market are mostly driven by pre-paid users.
The Theory of Generativity

On several occasions, during the period that Jonathan Zittrain and I were working on our respective books, each of us had the opportunity to present his developing ideas to the other at some public event (in particular, at several memorable “Penn-Temple-Wharton” colloquia), and we used to joke that we were actually both working on different versions of the same book. It was just a joke, but as it turns out there was something to it; my book1 is all about “generativity” (though I don’t use the term), and Zittrain’s The Future of the Internet2 has more Jefferson in it than might be immediately apparent at first glance (though there are few explicit references thereto). Zittrain does tend to see the glass as half-empty, while I see it as half-full (following Jefferson, who once wrote to a friend that he found that “the flatteries of hope are as cheap, and pleasanter than the gloom of despair”3); but it is, at bottom, very much the same glass. Consider the very first sentence of chapter 1 of The Future of the Internet: “Today’s Internet is not the only way to build a network.”4 It is a simple and obvious point, of course—but one whose implications are surprisingly rich, often counterintuitive, and thoroughly indispensable for understanding what the Net is and where it might be headed. Though it is not the first sentence of my book,5 it could well have been, and quite possibly it should have been. The focus of my book is largely retrospective, so I reframe the point as a question: Given all of the other ways to build networks and inter-networks, why did this one, and not some other, become the Big One—i.e., “the Internet,” the single, ubiquitous communications medium that conquered the planet?6 It is surprising—at least, it was
Setting online policy with software defaults

Software is increasingly seen as a policy tool to influence societal concerns such as privacy, freedom of speech and intellectual property protection. A necessary step in this process is deciding what the ‘settings’ should be for the relevant software. One powerful setting in software is defaults. This article puts forth a framework for how default settings should be determined. This normative approach towards software settings stands apart from most previous scholarship, which focuses on the effect of software. The framework is illustrated with an example of an incorrectly set default in Apple's Airport Extreme wireless access point. Policymakers can influence competition, security, and privacy by relying on this framework. We believe that the manipulation of software to enhance social welfare is a powerful tool and a useful complement to traditional legal methods. This material is based upon work supported by the National Science Foundation under Grant No. IIS-0429217. Any opinions, findings, and conclu...
On the Origins of le Droit Moral: How Non-Economic Rights Came to be Protected in French IP Law

In France, le droit moral, the moral right, provides legal protection for the non-economic interests of writers, visual artists, and performing artists. The received wisdom is that le droit moral developed from the work of German philosophers like Kant and Hegel, as well as many French theorists. In this article, however, I argue that these rights developed in France long before German philosophers and French scholars articulated the theoretical underpinnings. This article identifies the origins of le droit moral in the history of French intellectual property law. It reports on such disparate influences as Cicero’s complaints against his publisher, a 1504 Parisian court decision finding for a writer against an unauthorized printer, and the detailed regulations imposed on the playwrights of the Comedie Francaise during the ancient regime. Although le droit moral was not included in the core copyright statutes forged during the French Revolution, court decisions in the next decades protected le droit moral in matter-of-fact language. I submit that the sensibility to protect these rights was already developed in the culture of France, thanks to its eighteenth century dramatists.
The Environment as a Stakeholder? A Fairness-Based Approach

Stakeholder theory is often unable to distinguish those individuals and groups that are stakeholders from those that are not. This problem of stakeholder identity has recently been addressed by linking stakeholder theory to a Rawlsian principle of fairness. To illustrate, the question of stakeholder status for the non-human environment is discussed. This essay criticizes a past attempt to ascribe stakeholder status to the non-human environment, which utilized a broad definition of the term "stakeholder." This paper then demonstrates how, despite the denial of stakeholder status, the environment is nonetheless accounted for on a fairness-based approach through legitimate organizational stakeholders. In addition, since stakeholder theory has never claimed to be a comprehensive ethical scheme, it is argued that sound reasons might exist for managers to consider their organization's impact on the environment that are not stakeholder-related.
Climate Change, Intergenerational Equity, and International Law

Climate change is an inherently intergenerational problem with extremely serious implications for equity between ourselves and future generations and among communities in the present and the future. More than twenty years ago I wrote an article entitled Climate Change, Intergenerational Equity and International Law. The basic issues and the analysis remain the same, though a number of international agreements relevant to climate change have been concluded since then.
Is regulation to blame for the decline in American entrepreneurship

Mounting evidence suggests that economic dynamism and entrepreneurial activity are declining in the United States. Over the past 30 years, the annual number of new business startups and the pace of job reallocation have declined significantly. We ask whether this decline in dynamism can be explained by federal regulation. We combine measures of dynamism with RegData, a novel dataset leveraging the text of the Code of Federal Regulations to create annual measures of the total quantity of regulation by industry. We find that rising federal regulation cannot explain secular trends in economic dynamism.
Viewing Spatial Consequences of Budgetary Policy Changes

This study was supported, in part, by funding from The Health Foundation of Greater Cincinnati.
Facilitating Mergers and Acquisitions with Earnouts and Purchase Price Adjustments

This paper examines how post-closing contingent payment (PCP) mechanisms, such as earnouts and purchase price adjustments (PPAs), can facilitate mergers and acquisitions transactions. The paper examines two informational environments: in the first, the seller has superior information about the value of the assets (private information setting) and in the second, the parties differ in their estimates on the value but are unable to overcome their difference (non-convergent priors setting). The paper also allows the parties to use either cash or the buyerâ€™s stock as consideration. By conditioning payment on post-closing, verifiable information, PCPs can mitigate the problems of private information or non-convergent priors. In the private information setting, PCPs function as an imperfect verification mechanism (like a product warranty) and can lead to all parties using the same PCP. In the non-convergent priors setting, PCPs can be used to satisfy different, non-convergent beliefs. The paper also addresses the issues of size limitations on PCPs and post-closing incentives to maximize (or minimize) the PCP (particularly, earnout) payments. When such issues are a concern, the paper shows that (1) neither party may use a PCP (particularly an earnout); and (2) stock-based PCPs will generally function better than cash-based PCPs. Stock works better because (1) its value is partially correlated with the value of the combined company, thereby reducing the burden of having to structure a large contingent payment; and (2) with respect to post-closing moral hazard, the parties partly internalize the deadweight loss from engaging in earnings manipulation.
The Effect of Junk Bond Defaults on Common Stock Returns

This paper examines the effect of junk bond defaults on common stock returns. The evidence indicates that stockholders uncover the signs of financial distress long before the default date. Stock prices fall sharply at the time of the default announcement. Although stocks of fallen angel sample recover slowly and steadily after the default announcement, stocks of the original-issue junk bond sample continue to decline. On average, bankrupt firms suffer larger negative stock returns than defaulted firms not only at the time of announcement, but also in both pre- and post-event periods.
International Pension Swaps

During the past twenty years, swap contracts have become key financial ‘adapters’ linking diverse national financial systems to the global financial network. Today banks and investment companies around the world use swaps extensively to manage their currency, interest-rate, and equity-market risks and to lower their transaction costs. Yet pension funds, which have grown rapidly over that same 20-year period, hardly use swaps at all. This paper suggests how pension funds could use swaps to achieve the risk-sharing benefits of broad international diversification and hedging while avoiding the ‘flight’ of scarce domestic capital to other countries. The paper also shows how swaps can be used to lower the risks of expropriation and to lower the other transaction costs of investing in other countries.
Lawyers Should Be Lawyers, But What Does That Mean?: A Response to Aiken & Wizner and Smith

Lawyers should be more like social workers. That is the message of Law as Social Work, the provocative essay by Jane Aiken and Stephen Wizner (Aiken & Wizner) in the Washington University Journal of Law & Policy volume, which preceded the conference on Promoting Justice Through Interdisciplinary Teaching, Practice, and Scholarship, hosted by Washington University School of Law in March 2003. Almost as if in reply, Abbe Smith’s contribution to the same pre-conference volume reasserts the importance of lawyers as zealous and partisan advocates, using the realities of the criminal defense context to argue for the value of the lawyer’s traditional adversarial role.This article begins with a review of the Aiken & Wizner and Smith articles, pointing out the themes that are common to both and the tensions in their competing visions of justice and professionalism. The second part of the article explores the tensions between the professional perspectives of lawyers and social workers, as reflected in those differing conceptions of social justice, and analyzes how those differing visions affect issues of systemic role and relationships with clients. The third part turns to a discussion of how these tensions have played out in the field of juvenile justice, in which law and social work have historically interacted. The article concludes by affirming the traditional adversarial ethical role of lawyers, while further suggesting ways in which the work of lawyers can be broadened and enhanced by embracing some aspects of the social work perspective.
Localist Statutory Interpretation

This paper argues for more attention to citizens’ point of contact with our legal system within local courts – and makes an effort to conceptualize local judges as parts of local governments. Once the paper highlights the role of local courts within the constellation of local government, it offers an argument for why certain forms of "localist judging" are appropriate postures for local judges to take when confronted with hard cases of statutory interpretation. The paper explores the virtues of a type of "intrastate judicial federalism."
Keeping the Government's Hands Off Our Bodies: Mapping a Feminist Legal Theory Approach to Privacy in Cross-Gender Prison Searches

The power of privacy is diminishing in the prison setting, and yet privacy is the legal theory prisoners rely upon most to resist searches by correctional officers. Incarcerated women in particular rely upon privacy to shield them from the kind of physical contact that male guards have been known to abuse. The kind of privacy that protects prisoners from searches by guards of the opposite sex derives from several sources, depending on the factual circumstances. Although some form of bodily privacy is embodied in the First, Fourth, Eighth, and Fourteenth Amendments, prisoners challenging the
The Future of Privacy Policies: A Privacy Nutrition Label Filled With Fair Information Practices

E-commerce continues to blossom as evidenced by online retail sales in excess of $33 billion over the first quarter 2008. This growth helps spur the staggering economy but also magnifies the serious threats surrounding personally identifying information (PII) submitted during e-commerce transactions. The most common threats, such as identity theft and aggregated data files, do the most damage when companies are careless (i.e., losing laptops filled with unencrypted data) or callous (selling data on the open market) with the PII they collect. The first line of defense against these threats is the electronic privacy policy. In theory, privacy policies are supposed to force companies to analyze and strengthen their privacy practices and then provide Web surfers with a detailed picture of what happens to their information upon submission. Privacy policies are most effective when Web site visitors can locate, read and comprehend their terms. Armed with this knowledge, individuals are supposed to make accurate privacy assessments before submitting information online. Problematically, contemporary privacy policies fail to live up to their promise because they are posted inconspicuously, purposefully vague and filled with legalese. This inaccessibility leads Web surfers to ignore privacy practices completely while they continue to submit PII blindly.Privacy policies can be effective if companies clearly and conspicuously discuss how their privacy terms relate to fair information practices (FIPs). FIPs are widely agreed upon guidelines covering the most important areas of the data trade - PII collection, use, storage and dissemination. The Federal Trade Commission has designated the five core FIPs to be notice, choice, access, integrity and enforcement. This article argues that a standardized privacy nutrition label - similar to the labels required by the Nutrition Labeling and Education Act - posted conspicuously on all e-commerce homepages can increase policy effectiveness. These federally mandated labels require companies to discuss their privacy practices in relation to each Key FIP. Although companies need not adopt specific policy terms or run their practices through a governmental clearinghouse, they must honestly disclose their practices. This is true of even the most unpopular practices such as external PII dissemination. Over time, consumers will become aware of these standardized labels, begin to understand FIPs, differentiate between privacy-protective and privacy-invasive practices and make better decisions before submitting PII.
Asymmetric reaction is rational behavior

De Bondt and Thaler (Int J Fore 9(3):355–371, 1995) point out that while von Neumann-Morgenstern (1947) utility functions, the axioms of cardinal utility (Copeland and Weston 1988), risk aversion, rational expectations, etc., have formed the basis for theories of choice under uncertainty, research in behavioral science, has either challenged these foundations or outright rejected them. Requiring investors to be utility maximizers, and using an approach similar to Scott-Horvath (J Financ 35(4):915–9¸1980), and arguing investors’ to have different utility for partial upper and partial lower moments, this paper proves that loss, regret, and myopic loss aversion and sign effects, is in fact central to understanding of rational behavior.
Agency and Internal Capital Market Inefficiency: Evidence from Banking Organizations

Using banking data, I provide evidence that agency problems are at the root of internal capital market inefficiency. I find that publicly traded bank holding companies (BHCs) are less efficient in their internal capital allocation than nonpublicly traded BHCs. This suggests that the divergence of interests between the chief executive officer and the shareholders is an important source of the internal capital misallocation. I also demonstrate that BHCs incorporating a tiered organizational structure are less efficient than nontiered BHCs, but only within a sample of BHCs that are publicly traded. These findings imply that a greater degree of rent-seeking activity by division managers contributes to internal capital market inefficiency only if the top manager is an agent. This is consistent with theoretical models that explain internal capital misallocations through the multiple layers of agency within an organization.
Investment Opportunity Sets, Operating Uncertainty, and Capital Market Pressure: Determinants of Investments in Tax Shelter Activities?

ABSTRACT: Prior research documents substantial variation in firms' tax avoidance activities and questions why some firms choose not to take advantage of the apparent benefits of tax planning (i.e., the “undersheltering puzzle”). We provide additional insight into the undersheltering puzzle by investigating the decision to invest in a tax shelter from the perspective of a firm's overall investment strategy. We examine whether three factors associated with traditional investment behavior (firms' investment opportunity sets, operating uncertainty, and capital market pressure) are also associated with investments in tax shelter activities. Our results suggest that firms with large investment opportunity sets and higher operating uncertainty are less likely to invest in tax shelters. We also find that firms with greater capital market pressure are more likely to invest in tax sheltering activities. Overall, we find that factors that influence firms' investment behavior help to explain why more firms do not inv...
Does Border Enforcement Protect U.S. Workers from Illegal Immigration

In this paper, we examine the impact of enforcement of the U.S.-Mexico border on wages in U.S. and Mexican border regions. The U.S. Border Patrol polices U.S. boundaries, seeking to apprehend any undocumented entrants. It concentrates its efforts on the Mexican border. We examine labor markets in border areas of California, Texas, and Mexico. For each region, we have high-frequency data on wages and person hours the U.S. Border Patrol spends policing the border. For a range of empirical specifications and definitions of regional labor markets, we find little impact of border enforcement on wages in U.S. border cities and a moderate negative impact of border enforcement on wages in Mexican border cities. These findings are consistent with two hypothesis: (1) border enforcement has a minimal impact on illegal immigration, or (2) illegal immigration from Mexico has a minimal impact on wages in U.S. border areas.
Zone Pricing in Retail Oligopoly

We quantify the welfare effects of zone pricing, or setting common prices across distinct markets, in retail oligopoly. Although monopolists can only increase profits by price discriminating, this need not be true when firms face competition. With novel data covering the retail home-improvement industry, we find that Home Depot would benefit from finer pricing but that Lowe's would prefer coarser pricing. Zone pricing softens competition in markets where firms compete, but it shields consumers from higher prices in rural markets, where firms might otherwise exercise market power. Overall, zone pricing produces higher consumer surplus than finer price discrimination does.
Engaging Supply Chains in Climate Change

Suppliers are increasingly being asked to share information about their vulnerability to climate change and their strategies to reduce greenhouse gas emissions. Their responses vary widely. We theorize and empirically identify several factors associated with suppliers being especially willing to share this information with buyers, focusing on attributes of the buyers seeking this information and of the suppliers being asked to provide it. We test our hypotheses using data from the Carbon Disclosure Project's Supply Chain Program, a collaboration of multinational corporations requesting such information from thousands of suppliers in 49 countries. We find evidence that suppliers are more likely to share this information when requests from buyers are more prevalent, when buyers appear committed to using the information, when suppliers belong to more profitable industries, and when suppliers are located in countries with greenhouse gas regulations. We find evidence that these factors also influence the comprehensiveness of the information suppliers share and their willingness to share the information publicly.
Declining prices in sequential auctions with complete revelation of bids

Abstract In a sequential-auction setting, the expected-winning prices are shown to decline across two stages when all bids are revealed between the stages. The prices decline because bidders desire to hide their private valuation information. The hiding also leads to inefficient allocations.
Externalities and Industrial Development

Abstract Using panel data for five capital goods industries, this paper estimates dynamic externalities. In contrast to previous studies, panel data allow separation of externalities from fixed effects and identification of a lag structure. I find strong evidence of Marshall–Arrow–Romer (MAR) (own industry, or localization) externalities. For Jacobs (urbanization) externalities effects are smaller. In terms of lag structure, for MAR externalities the biggest effects are typically from several years ago, but die out after six years. For urbanization phenomena, effects persist to the end of the time horizon of the data–eight or nine years back.
THE EFFECTS OF SONS AND DAUGHTERS ON MEN' S LABOR SUPPLY AND WAGES

In this paper, we estimate the effects of children and the differential effects of sons and daughters on men's labor supply and hourly wage rates. The responses to fatherhood of two cohorts of men from the PSID sample are examined separately, and we use fixed-effects estimation to control for unobserved heterogeneity. We find that fatherhood significantly increases the hourly wage rates and annual hours of work for men from both cohorts. Most notably, men's labor supply and wage rates increase more in response to the births of sons than to the births of daughters.
How effectively does multilateral food aid respond to fluctuating needs

Abstract This paper tests the targeting efficacy of multilateral food aid at the level of nation states, exploring whether it stabilizes food availability in recipient economies, flows most to those with the greatest need, or both. We find that, unlike bilateral flows from the United States under PL 480, multilateral food aid distribution by the World Food Programme flows countercyclically, thereby stabilizing food availability in recipient economies. WFP flows also exhibit significant progressivity at the regional level, helping to resolve international inequalities in food availability per capita.
Forecasting Residential Real Estate Price Changes from Online Search Activity

The intention of buying a home is revealed by many potential home buyers when they turn to the Internet to search for their future residence. This paper examines the extent to which future cross-se...
Allocation of inventive effort in complex product systems

This paper examines the allocation of inventive effort in complex product systems. I argue that complex product systems, e.g., personal computers (PCs), are distinguished by functional interaction among several components, each guided by a relatively autonomous bundle of technical and economic characteristics. I try to explore whether the dynamics of such interactions between components of complex product systems can help us understand changes in the relative allocation of inventive effort. I advance and empirically test three hypotheses: (1) emergence of component constraints (bottlenecks) in product systems will trigger research and development (RD (2) slack component firms have a strong incentive to invest in resolving component constraints; and (3) the incentive of slack component firms to invest in resolving component constraints is increasing in their prior sunk R&D investments in slack components. In sum, I argue that interactions between components in a product system conditions the R&D incentives of firms and also that the incentives are increasing in their prior investments or capabilities. Using product reviews from technical journals, I trace the constraint components in the PC from 1981 to 1998 and attempt to predict shifts in the allocation of inventive effort in the subsequent period. The empirical results strongly support all three hypotheses. This study highlights the paradoxical effect of modularity in complex product systems. Modular design architectures, while contributing to accelerating the pace of technical change, also tend to limit the economic benefits of firms' component R&D efforts, especially when different components technologies are progressing at different rates. This often creates an impetus to enlarge the scope of firm R&D activities beyond the component product markets that firms operate in. Other implications for R&D decision making are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
The fear of liability and the use of restraints in nursing homes.

The routine use of chemical and physical restraints in nursing homes is bad care. Medical and nursing literature on the care of nursing home patients consistently criticizes the use of restraints when that use is unrelated to diagnosis and treatment considerations. Federal and state laws have included restrictions on the use of restraints for some time. The criticisms of inappropriate and indiscriminate use of chemical and physical restraints are not new. What, then, supports their continued misuse despite the ordinarily powerful combination of professional and governmental approbation? The use of restraints responds to generally quite acceptable and desirable patient-oriented goals. Restraints are used in an attempt to protect the patient with physical or mental disabilities from avoidable injury caused by falling or wandering away from the facility. In the social context of nursing homes, restraints are also used to protect residents from injury by threatening, violent patients. When the rationale is measured against the known effects of restraints, however, the self-evident nature of the justification begins to break down.
A comparison of some structural models of private information arrival

Abstract We show that the PIN and the Duarte and Young (2009) (APIN) models do not match the variability of noise trade in the data and that this limitation has severe implications for how these models identify private information. We examine two alternatives to these models, the Generalized PIN model (GPIN) and the Odders-White and Ready (2008) model (OWR). Our tests indicate that measures of private information based on the OWR and GPIN models are promising alternatives to the APIN’s Adj.PIN and PIN.
Double-consciousness in constitutional adjudication

Constitutional theorists are familiar with epistemic and consequentialist reasons why judges might allow their decision making to be shaped by strongly held public opinion. The epistemic approach treats public opinion as an expert indicator, while the consequentialist approach counsels judges to compromise legally correct interpretations so as not to antagonize a hostile public. But there is also a third reason, which we can think of as constitutive. In limited circumstances, the fact that the public strongly holds a given view can be one of the factors that together constitute the correct answer to a constitutional question. In those circumstances, what the public thinks must be an ingredient in the judge’s own view of the right answer.
Is “Pay-to-Play” Driving Public Pension Fund Activism in Securities Class Actions? An Empirical Study

The recent emergence of public pension funds as frequent lead plaintiffs in securities class actions has prompted speculation that the funds’ litigation activism is driven by “pay-to-play”. “Pay-to-play” posits that public pension funds are driven by politician board members to obtain lead plaintiff appointments in securities class actions because of campaign contributions made by plaintiffs’ lawyers to those board members. This paper provides a comprehensive analysis of the securities litigation activity of 111 such funds from the years 2003 through 2006. Three of the paper’s findings cast doubt on the “pay-to-play” theory, including that: (1) politicians and political control negatively correlate with lead plaintiff appointments; (2) beneficiary board members - and outright beneficiary control of the board - positively correlate with such appointments; and (3) the degree of a pension fund’s underfunding positively correlates with lead plaintiff appointments, particularly when the fund is controlled by beneficiaries. The substantial role played by beneficiary board members in driving the funds’ litigation activism is analyzed by the author in the context of prior literature comparing such board members to corporate managers with an equity stake in a corporation. The paper also finds no support for the theory that unions drive beneficiary board members to obtain lead plaintiff appointments, and offers evidence that resistance by politicians to lead plaintiff appointments correlates with the degree of business influence in the politicians’ home states.
Cycles, cocycles, and duality on tropical manifolds

We prove a Poincare duality for the Chow rings of smooth fans whose support are tropical linear spaces. As a consequence, we show that cycles and cocycles on tropical manifolds are Poincare dual to each other. This allows us to define pull-backs of tropical cycles along arbitrary morphisms with smooth target.
Measuring real economic effects of bailouts: historical perspectives on how countries in financial distress have fared with and without bailouts☆

Abstract In this paper we first trace the changing nature of banking, currency, and debt crises from the last century to the present. Each type of crisis has transmogrified in the presence of official intervention and the creation of a safety net. A similar pattern is observed for international rescue loans. We then present evidence suggesting that the incidence has increased and the severity of financial crises has changed little in emerging markets from the pre-1914 era to the present. Finally we assess the impact of IMF loans on the macro performance of the recipients. A simple with-without comparison of countries receiving IMF assistance during crises in the period 1973–98 with countries in the same region not receiving assistance suggests that the real performance of the former group was possibly worse than the latter. Similar results obtain adjusting for self-selection bias and counterfactual policies.
A century of capital structure: The leveraging of corporate America

Unregulated US corporations dramatically increased their debt usage over the past century. Aggregate leverage—low and stable before 1945—more than tripled between 1945 and 1970 from 11% to 35%, eventually reaching 47% by the early 1990s. The median firm in 1946 had no debt, but by 1970 had a leverage ratio of 31%. This increase occurred in all unregulated industries and affected firms of all sizes. Changing firm characteristics are unable to account for this increase. Rather, changes in government borrowing, macroeconomic uncertainty, and financial sector development play a more prominent role. Despite this increase among unregulated firms, a combination of stable debt usage among regulated firms and a decrease in the fraction of aggregate assets held by regulated firms over this period resulted in a relatively stable economy-wide leverage ratio during the 20th century.
European Law: Thinking About It and Teaching It - An Introduction to the Symposium (Dimensions of European Union Law: A Symposium)

My central aim in organizing this symposium (Dimensions of European Union Law) was to present U.S. law teachers with tools that should be of value in thinking about, analyzing and teaching the law of the European Union (EU). In recent years, growth and change within the EU have provided an extraordinary amount of legal “data” from and about the EU, and the computer has put much of it at every law professor’s fingertips. The challenge lies in penetrating, organizing and interpreting this expanse of information. It is a daunting task for any observer, but particularly for U.S. legal scholars and teachers who are seldom in a position to focus their primary energies on following these developments and who frequently lack some of the background knowledge about European politics, policies and cultures that can be important for understanding what is happening within the Union. This introduction offers some analytical tools for making sense of the EU.
diBELLA: Distributed Long Read to Long Read Alignment

We present a parallel algorithm and scalable implementation for genome analysis, specifically the problem of finding overlaps and alignments for data from "third generation" long read sequencers [29]. While long sequences of DNA offer enormous advantages for biological analysis and insight, current long read sequencing instruments have high error rates and therefore require different approaches to analysis than their short read counterparts. Our work focuses on an efficient distributed-memory parallelization of an accurate single-node algorithm for overlapping and aligning long reads. We achieve scalability of this irregular algorithm by addressing the competing issues of increasing parallelism, minimizing communication, constraining the memory footprint, and ensuring good load balance. The resulting application, diBELLA, is the first distributed memory overlapper and aligner specifically designed for long reads and parallel scalability. We describe and present analyses for high level design trade-offs and conduct an extensive empirical analysis that compares performance characteristics across state-of-the-art HPC systems as well as a commercial cloud architectures, highlighting the advantages of state-of-the-art network technologies.