5,428 research outputs found

    Individually-rational collective choice

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    In this paper I consider the following problem: there is a collection of exogenously given socially feasible sets, and for each one of them, each one of a group of individuals chooses from an individually feasible set. The fact that the product of the individually feasible sets is larger than the socially feasible set notwithstanding, there arises no conflict between individuals. Assuming that individual preferences are random, I here characterize collective choices in terms of the way in which individual preferences must co-vary in order to explain them. I do this by combining standard revealed preference theory and its counterpart under random preferences. I also argue that there exist collective choices that cannot be rationalized, and hence that the individual rationality assumption can be refuted

    Identification of individual demands from market data under uncertainty

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    We show that, even under incomplete markets, the equilibrium manifold identifies individual demands everywhere in their domains. Under partial observation of the manifold, we determine maximal subsets of the domains on which identification holds. For this, we assume conditions of smoothness, interiority and regularity. It is crucial that there be date-zero consumption. As a by-product, we develop some duality theory under incomplete markets

    A nonparametric analysis of the Cournot model

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    An observer makes a number of observations of an industry producing a homogeneous good. Each observation consists of the market price, the output of individual firms and perhaps information on each firm's production cost. We provide various tests (typically, linear programs) with which the observer can determine if the data set is consistent with the hypothesis that firms in this industry are playing a Cournot game at each observation. When cost information is wholly or partially unavailable, these tests could potentially be used to derive cost information on the firms. This paper is a contribution to the literature that aims to characterize (in various contexts) the restrictions that a data set must satisfy for it to be consistent with Nash outcomes in a game. It is also inspired by the seminal result of Afriat (and the subsequent literature) which addresses similar issues in the context of consumer demand, though one important technical difference from most of these results is that the objective functions of firms in a Cournot game are not necessarily quasiconcave

    Identification of preferences from market data

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    We offer a new proof that the equilibrium manifold (under complete markets) identifies individual demands globally. Moreover, under observation of only a subset of the equilibrium manifold, we find domains on which aggregate and individual demands are identifiable. Our argument avoids the assumption of Balasko (2004) requiring the observation of the complete manifold

    Ab initio spectroscopic characterization of the radical CH3_3OCH2_2 at low temperatures

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    Spectroscopic and structural properties of methoxymethyl radical (CH3_3OCH2_2, RDME) are determined using explicitly correlated ab initio methods. This radical of astrophysical and atmospheric relevance has not been fully characterized at low temperatures, which has delayed the astrophysical searches. We provide rovibrational parameters, excitations to the low energy electronic states, torsional and inversion barriers and low vibrational energy levels. In the electronic ground state (X2^2A), which appears "clean" from non-adiabatic effects, the minimum energy structure is an asymmetric geometry which rotational constants and dipole moment have been determined to be A0_0=46718.6745 MHz, B0_0=10748.4182 MHz, and C0_0=9272.5105 MHz, and 1.432 D (μA\mu_A=0.6952 D, μB\mu_B=1.215 D, μC\mu_C=0.3016 D), respectively. A variational procedure has been applied to determine torsion-inversion energy levels. Each level splits into 3 subcomponents (A1_1/A2_2 and E) corresponding to the three methyl torsion minima. Although the potential energy surface presents 12 minima, at low temperatures, the infrared band shapes correspond to a surface with only three minima because the top of the inversion Vα^{\alpha} barrier at α=0{\alpha}=0^{\circ} (109 cm1^{-1}) stands below the zero point vibrational energy and the CH2_2 torsional barrier is relatively high (\sim2000 cm1^{-1}). The methyl torsion barrier was computed to be \sim500 cm1^{-1} and produces a splitting of 0.01 cm1^{-1} of the ground vibrational state

    Genetic and Molecular Factors in Drug-Induced Liver Injury: A Review

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    The diagnosis of drug-induced liver injury (DILI) is challenging and based on complex diagnostic criteria. DILI falls into two main categories i) intrinsic 'dose-dependent' Type A reactions ii) 'idiosyncratic' or Type B reactions (which are usually not predictable). Idiosyncratic reactions can be immunoallergic (hypersensitivity), or metabolic, although overlap between categories can occur. The aim of this review is to summarise the general view of underlying mechanisms in DILI and to highlight individual risk factors for developing hepatotoxicity. Polymorphisms of bioactivation/ toxification pathways through CYP450 enzymes (Phase I), detoxification reactions (Phase II) and excretion/transport (Phase III) are explored together with immunological factors that might determine DILI. The importance of establishing a multidisciplinary and multi-centric network to promote the understanding and research in hepatotoxicity is underlined. Challenges such as genetic analyses for association studies and whole genome studies, pharmacogenetic testing and future approaches to study DILI are considered. Knowledge regarding these operational mechanisms could provide further insight for the prospective identification of susceptible patients at risk of developing drug-induced hepatotoxicity.

    Carpal tunnel syndrome associated with oral bisphosphonates. A population-based cohort study

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    © 2016 Carvajal et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: Bisphosphonates are widely used to prevent osteoporotic fractures. Some severe musculoskeletal reactions have been described with this medication; among them, some cases of carpal tunnel syndrome. Thus, the aim of this study was to explore whether bisphosphonates may be associated with this syndrome. Methods: A cohort study was conducted to compare exposed to unexposed women; the exposed group was that composed of women having received at least one prescription of an oral bisphosphonate. For the purpose, we used information from The Health Improvement Network (THIN) database. The outcome of interest was defined as those women diagnosed with carpal tunnel syndrome. A survival analysis was performed; the Cox proportional hazard model was used to calculate hazard ratios and 95% confidence intervals, and to adjust for identified confounding variables. Results: Out of a sample of 59,475 women older than 51 years, 19,825 were treated with bisphosphonates during the period studied. No differences in age distribution or mean follow-up time were observed between the two groups in comparison. Overall, there were 572 women diagnosed with carpal tunnel syndrome, 242 (1.2%) in the group exposed to bisphosphonates, and 330 (0.8%) in the unexposed. An adjusted hazard ratio of developing carpal tunnel syndrome of 1.38 (95%CI, 1.15-1.64) was found for women exposed to bisphosphonates; no significant changes in the hazard ratios were found when considering different levels of bisphosphonate exposure
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