372 research outputs found

    Rare region effects at classical, quantum, and non-equilibrium phase transitions

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    Rare regions, i.e., rare large spatial disorder fluctuations, can dramatically change the properties of a phase transition in a quenched disordered system. In generic classical equilibrium systems, they lead to an essential singularity, the so-called Griffiths singularity, of the free energy in the vicinity of the phase transition. Stronger effects can be observed at zero-temperature quantum phase transitions, at nonequilibrium phase transitions, and in systems with correlated disorder. In some cases, rare regions can actually completely destroy the sharp phase transition by smearing. This topical review presents a unifying framework for rare region effects at weakly disordered classical, quantum, and nonequilibrium phase transitions based on the effective dimensionality of the rare regions. Explicit examples include disordered classical Ising and Heisenberg models, insulating and metallic random quantum magnets, and the disordered contact process.Comment: Topical review, 68 pages, 14 figures, final version as publishe

    Improving the reach of vaccines to low-resource regions, with a needle-free vaccine delivery device and long-term thermostabilization

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    Dry-coated microprojections can deliver vaccine to abundant antigen-presenting cells in the skin and induce efficient immune responses and the dry-coated vaccines are expected to be thermostable at elevated temperatures. In this paper, we show that we have dramatically improved our previously reported gas-jet drying coating method and greatly increased the delivery efficiency of coating from patch to skin to from 6.5% to 32.5%, by both varying the coating parameters and removing the patch edge. Combined with our previous dose sparing report of influenza vaccine delivery in a mouse model, the results show that we now achieve equivalent protective immune responses as intramuscular injection (with the needle and syringe), but with only 1/30th of the actual dose. We also show that influenza vaccine coated microprojection patches are stable for at least 6 months at 23 degrees C. inducing comparable immunogenicity with freshly coated patches. The dry-coated microprojection patches thus have key and unique attributes in ultimately meeting the medical need in certain low-resource regions with low vaccine affordability and difficulty in maintaining "cold-chain" for vaccine storage and transport. (C) 2011 Elsevier B.V. All rights reserved

    Where do firms manage earnings?

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    Despite decades of research on how, why, and when companies manage earnings, there is a paucity of evidence about the geographic location of earnings management within multinational firms. In this study, we examine where companies manage earnings using a sample of 2,067 U.S. multinational firms from 1994 to 2009. We predict and find that firms with extensive foreign operations in weak rule of law countries have more foreign earnings management than companies with subsidiaries in locations where the rule of law is strong. We also find some evidence that profitable firms with extensive tax haven subsidiaries manage earnings more than other firms and that the earnings management is concentrated in foreign income. Apart from these results, we find that most earnings management takes place in domestic income, not foreign income.Arthur Andersen (Firm) (Arthur Andersen Faculty Fund

    Portfolio manager ownership and mutual fund performance

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    This paper examines the association between a mutual fund manager's personal fund investment and mutual fund performance. Newly-released managerial ownership disclosures reveal that fund ownership varies across mutual fund managers and, in many instances, is quite large. I find that mutual fund returns are increasing in the level of managerial fund investment, consistent with managerial ownership realigning decision-maker and shareholder interests. Also consistent with the reduction of agency costs, I find that managerial ownership is inversely related to fund turnover, which could affect both tax and trading costs. However, I do not find any association between portfolio manager ownership and a mutual fund's tax burden

    CEO Profile and Earnings Quality

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    This paper introduces the PSCORE, which aggregates nine personal characteristics of chief executive officers (CEOs), to signal the quality of earnings. The PSCORE is a composite score based on publicly available data on CEOs. The study reports strong positive relationships between the PSCORE and two different proxies for earnings quality, (i) discretionary accruals and (ii) financial statement errors, measured by deviations of the first digits of figures reported in financial statements from those expected by Benford’s Law. Further analyses indicate that the relationships between the PSCORE and the proxies for earnings quality become more pronounced when CEOs have high equity-based compensation incentives. The findings have some implications for practitioners

    Billions on the Sidewalk Improving Savings by Reducing Investment Mistakes

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    This paper contributes the on-going debate on income inequality in advanced economies with a proposal aimed at reducing costly investment mistakes that are prevalent among middle-class households. The paper starts by describing how households should invest, compares it with what we know about how households do invest, and highlights discrepancies between the two (investment mistakes). After evaluating the costs of investment mistakes, the paper suggests that they could be reduced by accommodating cognitive biases through a simple process of financial education and appropriate default options. The policy described in this paper is immediately actionable at basically no cost and can have a large effect on the welfare of middle-class households in advanced economies

    Us knows us in the UK: On director networks and CEO compensation

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    We analyze the relation between CEO compensation and networks of executive and non-executive directors for all listed UK companies over the period 1996-2007. We examine whether networks are built for reasons of information gathering or for the accumulation of managerial influence. Both indirect networks (enabling directors to collect information) and direct networks (leading to more managerial influence) enable the CEO to obtain higher compensation. Direct networks can harm the efficiency of the remuneration contracting in the sense that the performance sensitivity of compensation is then lower. We find that in companies with strong networks and hence busy boards the directors' monitoring effectiveness is reduced which leads to higher and less performance-sensitive CEO compensation. Our results suggest that it is important to have the 'right' type of network: some networks enable a firm to access valuable information whereas others can lead to strong managerial influence that may come at the detriment of the firm and its shareholders. We confirm that there are marked conflicts of interest when a CEO increases his influence by being a member of board committees (such as the remuneration committee) as we observe that his or her compensation is then significantly higher. We also find that hiring remuneration consultants with sizeable client networks also leads to higher CEO compensation especially for larger firms. © 2011 Elsevier B.V
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