240 research outputs found

    Garbled Elections

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    Majority rules are frequently used to decide whether or not a public good should be provided, but will typically fail to achieve an efficient provision. We provide a worst-case analysis of the majority rule with an optimally chosen majority threshold, assuming that voters have independent private valuations and are exante symmetric (provision cost shares are included in the valuations). We show that if the population is large it can happen that the optimal majority rule is essentially no better than a random provision of the public good. But the optimal majority rule is worst-case asymptotically efficient in the large-population limit if (i) the voters’ expected valuation is bounded away from 0, and (ii) an absolute bound for valuations is known

    Garbled Elections

    Get PDF
    Majority rules are frequently used to decide whether or not a public good should be provided, but will typically fail to achieve an efficient provision. We provide a worst-case analysis of the majority rule with an optimally chosen majority threshold, assuming that voters have independent private valuations and are exante symmetric (provision cost shares are included in the valuations). We show that if the population is large it can happen that the optimal majority rule is essentially no better than a random provision of the public good. But the optimal majority rule is worst-case asymptotically efficient in the large-population limit if (i) the voters’ expected valuation is bounded away from 0, and (ii) an absolute bound for valuations is known.

    The (sub-)optimality of the majority rule

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    We consider collective choice from two alternatives. Ex ante, each agent is uncertain about which alternative she prefers, and may be uncertain about the intensity of her preferences. An environment is given by a probability distribution over utility vectors that is symmetric across agents and neutral across alternatives. In many environments, the majority voting rule maximizes agents' ex-ante expected utilities among all anonymous and dominant-strategy implementable choice rules. But in some environments where the agents' utilities are stochastically correlated, other dominant-strategy choice rules are better for all agents. If utilities are stochastically independent across agents, majority voting is ex-ante optimal among all anonymous and incentive-compatible rules. We also compare rules from an interim viewpoint.majority rule

    Characterization of a CH planar laser-induced fluorescence imaging system using a kHz-rate multimode-pumped optical parametric oscillator

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    The performance characteristics of a new CH planar laser-induced fluorescence (PLIF) imaging system composed of a kHz-rate multimode-pumped optical parametric oscillator (OPO) and high-speed intensified CMOS camera are investigated in laminar and turbulent CH4-H2-air flames. A multi-channel Nd:YAG cluster that produces up to 225 mJ at 355 nm with multiple-pulse spacing of 100 μs (corresponding to 10 kHz) is used to pump an OPO to produce up to 6 mJ at 431 nm for direct excitation of the A-X (0, 0) band of the CH radical. Single-shot signal-to-noise ratios of 82∶1 and 7.5∶1 are recorded in laminar premixed flames relative to noise in the background and within the flame layer, respectively. The spatial resolution and image quality are sufficient to accurately measure the CH layer thickness of ∼0.4 mm while imaging the detailed evolution of turbulent flame structures over a 20 mm span. Background interferences due to polycyclic-aromatic hydrocarbons and Rayleigh scattering are minimized and, along with signal linearity, allow semi-quantitative analysis of CH signals on a shot-to-shot basis. The effects of design features, such as cavity finesse and passive injection seeding, on conversion efficiency, stability, and linewidth of the OPO output are also discussed

    Evidence for short range orbital order in paramagnetic insulating (Al,V)_2O_3

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    The local structure of (Al_0.06V_0.94)_2O_3 in the paramagnetic insulating (PI) and antiferromagnetically ordered insulating (AFI) phase has been investigated using hard and soft x-ray absorption techniques. It is shown that: 1) on a local scale, the symmetry of the vanadium sites in both the PI and the AFI phase is the same; and 2) the vanadium 3d - oxygen 2p hybridization, as gauged by the oxygen 1s absorption edge, is the same for both phases, but distinctly different from the paramagnetic metallic phase of pure V_2O_3. These findings can be understood in the context of a recently proposed model which relates the long range monoclinic distortion of the antiferromagnetically ordered state to orbital ordering, if orbital short range order in the PI phase is assumed. The measured anisotropy of the x-ray absorption spectra is discussed in relation to spin-polarized density functional calculations.Comment: 8 pages, 5 figure

    Identifying Appropriate Nursing Home Resources to Reduce Fall-Related Emergency Department Transfers.

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    OBJECTIVES To describe potentially avoidable fall-related transfers to the emergency department (ED), and to identify infrastructure, training needs, and resources deemed appropriate for implementation in nursing homes (NHs) to decrease fall-related transfers to EDs. DESIGN A multi-method design, including (1) in-depth case review by an expert panel, (2) structured discussion with NH stakeholders, and (3) appropriateness rating. SETTING AND PARTICIPANTS Fall-related transfers were identified from the prospective reporting of every unplanned hospital transfer occurring within 21 months, collected during the INTERCARE study in 11 Swiss NHs. METHODS Eighty-one fall-related transfers were rated for avoidability by a 2-round expert panel. NH stakeholders were consulted to discuss key implementable resources for NHs to mitigate potentially avoidable fall-related transfers. A questionnaire composed of 21 contextually adapted resources was sent to a larger group of stakeholders, to rate the appropriateness for implementation in NHs. χ2 tests were used to assess whether avoidability was associated with an ED visit and to describe transfers. The RAND/UCLA method for appropriateness was used to determine appropriate resources. RESULTS One of 4 fall-related transfers were rated as potentially avoidable. A positive association was found between an ED visit and a rating of avoidability (χ2 (1, N = 81) = 18.0, P < .001). Fourteen resources, including developing partnerships with outpatient clinics to access imaging services and strengthening geriatric expertise in nursing homes through clinical training and advanced nurse practitioners, were rated as appropriate by NH stakeholders for NH implementation to reduce potentially avoidable fall-related ED transfers. CONCLUSIONS AND IMPLICATIONS Access to diagnostic equipment, geriatric expertise, and clinical training is essential to reduce fall-related potentially avoidable transfers from NHs. Implementing and supporting advanced practice nurses or nurses in extended roles provides NH directors, policymakers, and health care institutions with the possibility of re-engineering resources to limit unnecessary transfers, which are detrimental for resident quality of care and costly for the health system
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