6,096 research outputs found

    Mechanism Choice

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    This chapter reviews the literature on the selection of regulatory policy instruments, from both normative and positive perspectives. It first reviews the mechanism design literature to identify normative objectives in selecting among the menu or toolbox of policy instruments. The chapter then discusses the public choice and positive political theory literatures and the variety of models developed to attempt to predict the actual selection of alternative policy instruments. It begins with simpler early models focusing on interest group politics and proceeds to more complicated models that incorporate both supply and demand for policy, the role of policy entrepreneurs, behavioral and cognitive choice, and public perceptions and mass politics. It compares these theories to empirical experience. The chapter examines literature in law, economics, political science, and related fields, and it draws examples from US, European, and international regulation. It concludes with suggestions for future research. Document is the author\u27s manuscrip

    Mechanism Choice

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    Mechanism choice can generally be described as the selection of some way to structure rules for social behavior. Nobel Laureate Eric Maskin recently described a mechanism as “an institution, procedure, or game for determining outcomes” (Maskin 2008: 568). In the realm of public law, mechanism choice is synonymous with “instrument choice” or policy design. The selection of the policy instrument can be as important to success or failure as the intended policy outcome. Good intentions or objectives are not enough: the choice of tools matters. A large and growing literature in instrument choice and mechanism design examines both the normative criteria for correcting market failures, matching optimal instruments to different types of problems, minimizing costs, and overcoming incomplete information; and also the positive political factors that may influence the actual selection of instruments, and the pattern of such choices across issue areas, governance systems, and time. Public policy instruments are selected and designed by public bodies –legislatures, executive agencies, and courts – that are comprised of individuals with their own policy preferences, and that are subject to pressures from private interests through lobbying, campaign contributions, and elections. Thus, it is no surprise to the student of public law that the mechanisms actually selected to implement public policy are not necessarily the ones that best pursue the public interest. This chapter begins with a brief summary of normative mechanism choice, including the legal literature on instrument choice and the economics literature on mechanism design. It then moves to a more detailed discussion of positive mechanism choice, also called public choice, political economy, or positive politics. This positive literature explores how political institutions and pressures shape the selection of mechanisms to implement policy, notably when the selected instrument departs from the normative ideal. The positive study of mechanism choice not only informs how political processes shape policy outcomes, but also sheds useful insights into those processes themselves.

    Spatially resolved electrochemistry in ionic liquids : surface structure effects on triiodide reduction at platinum electrodes

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    Understanding the relationship between electrochemical activity and electrode structure is vital for improving the efficiency of dye-sensitized solar cells. Here, the reduction of triiodide to iodide in 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm][BF4]) room temperature ionic liquid (RTIL) is investigated on polycrystalline platinum using scanning electrochemical cell microscopy (SECCM) and correlated to the crystallographic orientation from electron backscatter diffraction (EBSD). Although the rate determining step in all grains was the first electron transfer, significant grain-dependent variations in activity were revealed, with grains with a dominant (110) crystallographic character exhibiting higher catalytic activity compared to those with a major (100) orientation. The SECCM technique is demonstrated to resolve heterogeneity in activity, highlighting that methods incorporating polycrystalline electrodes miss vital details for understanding and optimizing electrocatalysts. An additional advantage of the SECCM over single-crystal techniques is its ability to probe high index facets

    Secret-Sharing for NP

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    A computational secret-sharing scheme is a method that enables a dealer, that has a secret, to distribute this secret among a set of parties such that a "qualified" subset of parties can efficiently reconstruct the secret while any "unqualified" subset of parties cannot efficiently learn anything about the secret. The collection of "qualified" subsets is defined by a Boolean function. It has been a major open problem to understand which (monotone) functions can be realized by a computational secret-sharing schemes. Yao suggested a method for secret-sharing for any function that has a polynomial-size monotone circuit (a class which is strictly smaller than the class of monotone functions in P). Around 1990 Rudich raised the possibility of obtaining secret-sharing for all monotone functions in NP: In order to reconstruct the secret a set of parties must be "qualified" and provide a witness attesting to this fact. Recently, Garg et al. (STOC 2013) put forward the concept of witness encryption, where the goal is to encrypt a message relative to a statement "x in L" for a language L in NP such that anyone holding a witness to the statement can decrypt the message, however, if x is not in L, then it is computationally hard to decrypt. Garg et al. showed how to construct several cryptographic primitives from witness encryption and gave a candidate construction. One can show that computational secret-sharing implies witness encryption for the same language. Our main result is the converse: we give a construction of a computational secret-sharing scheme for any monotone function in NP assuming witness encryption for NP and one-way functions. As a consequence we get a completeness theorem for secret-sharing: computational secret-sharing scheme for any single monotone NP-complete function implies a computational secret-sharing scheme for every monotone function in NP

    Analytic Evidence for Continuous Self Similarity of the Critical Merger Solution

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    The double cone, a cone over a product of a pair of spheres, is known to play a role in the black-hole black-string phase diagram, and like all cones it is continuously self similar (CSS). Its zero modes spectrum (in a certain sector) is determined in detail, and it implies that the double cone is a co-dimension 1 attractor in the space of those perturbations which are smooth at the tip. This is interpreted as strong evidence for the double cone being the critical merger solution. For the non-symmetry-breaking perturbations we proceed to perform a fully non-linear analysis of the dynamical system. The scaling symmetry is used to reduce the dynamical system from a 3d phase space to 2d, and obtain the qualitative form of the phase space, including a non-perturbative confirmation of the existence of the "smoothed cone".Comment: 25 pages, 4 figure

    The complex links between governance and biodiversity

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    We argue that two problems weaken the claims of those who link corruption and the exploitation of natural resources. The first is conceptual. Studies that use national level indicators of corruption fail to note that corruption comes in many forms, at multiple levels, and may or may not affect resource use. Without a clear causal model of the mechanism by which corruption affects resources, one should treat with caution any estimated relationship between corruption and the state of natural resources. The second problem is methodological: Simple models linking corruption measures and natural resource use typically do not account for other important causes and control variables pivotal to the relationship between humans and natural resources. By way of illustration of these two general concerns, we demonstrate that the findings of a well known recent study that posits a link between corruption and decreases in forests, elephants, and rhinoceros are fragile to simple conceptual and methodological refinements.Environmental Economics and Policy,

    A Nearly Tight Sum-of-Squares Lower Bound for the Planted Clique Problem

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    We prove that with high probability over the choice of a random graph GG from the Erd\H{o}s-R\'enyi distribution G(n,1/2)G(n,1/2), the nO(d)n^{O(d)}-time degree dd Sum-of-Squares semidefinite programming relaxation for the clique problem will give a value of at least n1/2−c(d/log⁡n)1/2n^{1/2-c(d/\log n)^{1/2}} for some constant c>0c>0. This yields a nearly tight n1/2−o(1)n^{1/2 - o(1)} bound on the value of this program for any degree d=o(log⁡n)d = o(\log n). Moreover we introduce a new framework that we call \emph{pseudo-calibration} to construct Sum of Squares lower bounds. This framework is inspired by taking a computational analog of Bayesian probability theory. It yields a general recipe for constructing good pseudo-distributions (i.e., dual certificates for the Sum-of-Squares semidefinite program), and sheds further light on the ways in which this hierarchy differs from others.Comment: 55 page

    ER Stress-Induced eIF2-alpha Phosphorylation Underlies Sensitivity of Striatal Neurons to Pathogenic Huntingtin

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    A hallmark of Huntington's disease is the pronounced sensitivity of striatal neurons to polyglutamine-expanded huntingtin expression. Here we show that cultured striatal cells and murine brain striatum have remarkably low levels of phosphorylation of translation initiation factor eIF2 alpha, a stress-induced process that interferes with general protein synthesis and also induces differential translation of pro-apoptotic factors. EIF2 alpha phosphorylation was elevated in a striatal cell line stably expressing pathogenic huntingtin, as well as in brain sections of Huntington's disease model mice. Pathogenic huntingtin caused endoplasmic reticulum (ER) stress and increased eIF2 alpha phosphorylation by increasing the activity of PKR-like ER-localized eIF2 alpha kinase (PERK). Importantly, striatal neurons exhibited special sensitivity to ER stress-inducing agents, which was potentiated by pathogenic huntingtin. We could strongly reduce huntingtin toxicity by inhibiting PERK. Therefore, alteration of protein homeostasis and eIF2 alpha phosphorylation status by pathogenic huntingtin appears to be an important cause of striatal cell death. A dephosphorylated state of eIF2 alpha has been linked to cognition, which suggests that the effect of pathogenic huntingtin might also be a source of the early cognitive impairment seen in patients

    Equivalence Proofs for Multi-Layer Perceptron Classifiers and the Bayesian Discriminant Function

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    This paper presents a number of proofs that equate the outputs of a Multi-Layer Perceptron (MLP) classifier and the optimal Bayesian discriminant function for asymptotically large sets of statistically independent training samples. Two broad classes of objective functions are shown to yield Bayesian discriminant performance. The first class are “reasonable error measures,” which achieve Bayesian discriminant performance by engendering classifier outputs that asymptotically equate to a posteriori probabilities. This class includes the mean-squared error (MSE) objective function as well as a number of information theoretic objective functions. The second class are classification figures of merit (CFMmono ), which yield a qualified approximation to Bayesian discriminant performance by engendering classifier outputs that asymptotically identify themaximum a posteriori probability for a given input. Conditions and relationships for Bayesian discriminant functional equivalence are given for both classes of objective functions. Differences between the two classes are then discussed very briefly in the context of how they might affect MLP classifier generalization, given relatively small training sets

    Templates for stellar mass black holes falling into supermassive black holes

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    The spin modulated gravitational wave signals, which we shall call smirches, emitted by stellar mass black holes tumbling and inspiralling into massive black holes have extremely complicated shapes. Tracking these signals with the aid of pattern matching techniques, such as Wiener filtering, is likely to be computationally an impossible exercise. In this article we propose using a mixture of optimal and non-optimal methods to create a search hierarchy to ease the computational burden. Furthermore, by employing the method of principal components (also known as singular value decomposition) we explicitly demonstrate that the effective dimensionality of the search parameter space of smirches is likely to be just three or four, much smaller than what has hitherto been thought to be about nine or ten. This result, based on a limited study of the parameter space, should be confirmed by a more exhaustive study over the parameter space as well as Monte-Carlo simulations to test the predictions made in this paper.Comment: 12 pages, 4 Tables, 4th LISA symposium, submitted to CQ
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