296 research outputs found

    Providing Prescription Drug Coverage to the Elderly: America’s Experiment With Medicare Part D

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    The federal government\u27s Medicare program did not provide general prescription drug coverage for the first 40 years of its existence. Thus, more than 30 percent of the 44 million elderly and disabled beneficiaries of the program lacked insurance coverage for prescribed medications. The Medicare Prescription Drug, Improvement, and Modernization Act of 2003 established a voluntary outpatient prescription drug benefit known as Medicare Part D. This program took effect in 2006 and represents the largest expansion of an entitlement program since the start of Medicare itself. The design of Part D is of particular interest to economists for at least three reasons: First, the program has the potential to affect significantly both the health and the economic well-being of the more than 44 million individuals currently enrolled in Medicare. Second, Part D has substantially increased government spending on health care despite the projections that such spending was already on an unsustainable path. Third, Part D represents an ambitious attempt to use market mechanisms in the delivery of a large-scale entitlement program. Part D has been controversial. In this paper, we aim to shed light on the various issues raised by the Part D program, including the incentives inherent in the competition among plans, the forces that affect drug prices, and the sustainability of Part D in the face of adverse selection and moral hazard. We conclude that Part D has succeeded in a number of important ways, however, substantial room for improvement remains

    The influence of goal-state access cost on planning during problem solving

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    Two problem-solving experiments investigated the relationship between planning and the cost of accessing goal-state information using the theoretical framework of the soft constraints hypothesis (Gray & Fu, 2004; Gray, Simms, Fu, & Schoelles, 2006). In Experiment 1, 36 participants were allocated to low, medium, and high access cost conditions and completed a problem-solving version of the Blocks World Task. Both the nature of planning (memory based or display based) and its timing (before or during action) changed with high goal-state access cost (a mouse movement and a 2.5-s delay). In this condition more planning before action was observed, with less planning during action, evidenced by longer first-move latencies, more moves per goal-state inspection, and more short (≤0.8 s) and long (>8 s) “preplanned” intermove latencies. Experiment 2 used an eight-puzzle-like transformation task and replicated the effect of goal-state access cost when more complex planning was required, also confirmed by sampled protocol data. Planning before an episode of move making increased with higher goal-state access cost, and planning whilst making moves increased with lower access cost. These novel results are discussed in the context of the soft constraints hypothesis

    Search for Neutral Higgs Bosons in Events with Multiple Bottom Quarks at the Tevatron

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    The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6 fb-1 of integrated luminosity at CDF and 5.2 fb-1 at D0, have been collected in final states containing three or more b jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode.Comment: 10 pages, 2 figure

    Search for the standard model Higgs boson decaying to a bbˉb\bar{b} pair in events with no charged leptons and large missing transverse energy using the full CDF data set

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    We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at s=1.96\sqrt{s} = 1.96 TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb1^{-1}. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a bb quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and 150GeV/c2150 \mathrm{GeV}/c^2. For a Higgs boson mass of 125GeV/c2125 \mathrm{GeV}/c^2, the observed (expected) limit is 6.7 (3.6) times the standard model prediction.Comment: Accepted by Phys. Rev. Let

    Search for the standard model Higgs boson decaying to a bb pair in events with one charged lepton and large missing transverse energy using the full CDF data set

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    We present a search for the standard model Higgs boson produced in association with a W boson in sqrt(s) = 1.96 TeV p-pbar collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45 fb-1. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H->bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c2 we observe (expect) a limit of 4.9 (2.8) times the standard model value.Comment: Submitted to Phys. Rev. Lett (v2 contains clarifications suggested by PRL

    Search for the standard model Higgs boson decaying to a bb pair in events with two oppositely-charged leptons using the full CDF data set

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    We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45/fb. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H -> bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^2 we observe (expect) a limit of 7.1 (3.9) times the standard model value.Comment: To be submitted to Phys. Rev. Let

    Cell-specific microarray profiling experiments reveal a comprehensive picture of gene expression in the C. elegans nervous system

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    A novel strategy for profiling Caenorhabditis elegans cells identifies transcripts highly enriched in either the embryonic or larval C. elegans nervous system, including 19 conserved transcripts of unknown function that are also expressed in the mammalian brain
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