14,617 research outputs found
Towards a Competitive Health Care System
The antitrust laws constitute the foundation and fundamental strength of the U.S. democratic free enterprise system. Competition enhances both the democratic and economic opportunities, including in the healthcare markets. Although healthcare markets have significant market imperfections, a competitive system is more appropriate for the healthcare markets because it delivers choice among alternatives that regulation does not. Thus, the question to ask in the healthcare system is what can be done to make competition work better
Taxation, Corporate Capital Structure, and Financial Distress
Is corporate leverage excessive? Is the tax code distorting corporate capital structure decisions in a way that increases the possibility of an economic crisis owing to "financial instability"? Answering these kinds of questions first requires some precision in terminology. In this paper, we describe the cases for and against the trend toward high leverage, and evaluate the role played by taxation. While provision of proper incentives to managers may in part underlie the trend to the debt, high leverage may in practice be a blunt way to address the problem, and one which opens up the possibility for undue exposure to the risks of financial distress. Our story takes as given the kinds of managerial incentive problems deemed important by advocates of leverage. We maintain, however, that when a firm is subject to business-cycle risk as well as individual risk, a profit maximizing arrangement is not simple debt, but rather a contract with mixed debt and equity features. That is, the contract should index the principal obligation to aggregate and/or industry-level economic conditions. We argue that the tax system encourages corporations to absorb more business cycle risk than they would otherwise. It does so in two respects: First, it provides a relative subsidy to debt finance; second, it restricts debt for tax purposes from indexing the principal to common disturbances. At a deeper level, the issue hinges on the institutional aspects of debt renegotiation. If renegotiation were costless, then debt implicitly would have the equity features relevant for responding to business-cycle risk. However, because of the diffuse ownership pattern of much of the newly issued debt and also because of certain legal restrictions, renegotiation is likely to be a costly activity.
Limnology of Four Bauxite Open-Pit Lakes
The aquatic flora and fauna and 18 physicochemical characteristics of four bauxite open-pit lakes were studied from September 1969 to August 1970. The least acid lake (pH 3.4-4.4) supported 49 different aquatic insects, plankton, and higher aquatic plants. The most acid lake (pH 2.7-3.2) supported only 26 different plants and animals. Bauxite open-pit lakes within the pH range studied appear to be as relatively unproductive as their coal strip-mine lake counterparts, with which they share physicochemical and biological characteristics. Benthic macrofaunal diversity and abundance appear to be related more closely to distribution and abundance of leaf detritus than to hydrogen-ion concentration
Risk of cardiovascular events from current, recent, and cumulative exposure to abacavir among persons living with HIV who were receiving antiretroviral therapy in the United States: a cohort study.
BackgroundThere is ongoing controversy regarding abacavir use in the treatment of HIV infection and the risk of subsequent development of cardiovascular disease. It is unclear how the risk varies as exposure accumulates.MethodsUsing an administrative health-plan dataset, risk of cardiovascular disease events (CVDe), defined as the first episode of an acute myocardial infarction or a coronary intervention procedure, associated with abacavir exposure was assessed among HIV-infected individuals receiving antiretroviral therapy across the U.S. from October 2009 through December 2014. The data were longitudinal, and analyzed using marginal structural models.ResultsOver 114,470 person-years (n = 72,733) of ART exposure, 714 CVDe occurred at an incidence rate (IR) (95% CI) of 6·23 (5·80, 6·71)/1000 person-years. Individuals exposed to abacavir had a higher IR of CVDe of 9·74 (8·24, 11·52)/1000 person-years as compared to 5·75 (5·30, 6·24)/1000 person-years for those exposed to other antiretroviral agents. The hazard (HR; 95% CI) of CVDe was increased for current (1·43; 1·18, 1·73), recent (1·41; 1·16, 1·70), and cumulative [(1·18; 1·06, 1·31) per year] exposure to abacavir. The risk for cumulative exposure followed a bell-shaped dose-response curve peaking at 24-months of exposure. Risk was similarly elevated among participants free of pre-existing heart disease or history of illicit substance use at baseline.ConclusionCurrent, recent, and cumulative use of abacavir was associated with an increased risk of CVDe. The findings were consistent irrespective of underlying cardiovascular risk factors
Finite Lifetimes, Borrowing Constraints, and Short-Run Fiscal Policy
Recent developments in public finance in the analysis of dynamic government debt policies have emphasized effects on the distribution of real resources across generations. At the same time, macroeconomists have emphasized the importance of the length of the time horizon over which agents optimize their decisions about consumption for judging the effects of fiscal policy on aggregate demand. Much of the discussion of these issues has focused on whether linkages among generations are sufficient to give consumers infinite horizons. To the extent that horizons are finite, debt burdens can be shifted to future generations, and substitutions of debt for taxes have real effects. This paper argues that, as a matter of quantitative significance, theoretical and empirical emphasis on the importance of finite horizons for the analysis of many fiscal policies is misplaced. Studies of the role of finite horizons in determining the effects of short-run fiscal policies on consumption have been conducted largely under the assumption of perfect capital markets. We show that while the marginal propensity to consume (MPC) out of temporary tax changes is nonzero in finite- horizon models, it is not very large. We demonstrate that the MPC is, however, quite sensitive to the importance of restrictions on borrowing in the economy. The clear implication is that shifting emphasis from the length of the planning horizon to the structure of capital markets is an important step for empirical research.
Many-body approach to the nonlinear interaction of charged particles with an interacting free electron gas
We report various many-body theoretical approaches to the nonlinear decay
rate and energy loss of charged particles moving in an interacting free
electron gas. These include perturbative formulations of the scattering matrix,
the self-energy, and the induced electron density. Explicit expressions for
these quantities are obtained, with inclusion of exchange and correlation
effects.Comment: 11 pages, 5 figures. To appear in Journal of Physics
Social Security and Individual Welfare: Precautionary Saving, LiquidityConstraints, and the Payroll Tax
Recent advances in the examination of efficiency gains from dynamic tax reforms have used simulation models to isolate intragenerational and/or intergenerational effects. Important considerations having to do with uncertainty or capital market imperfections are frequently missing from such a framework. In this paper, we focus on the welfare gains from introducing social security retirement annuities, given lifetime uncertainty and borrowing restrictions.Our principal findings are four. First, given the considerations mentioned above, "precautionary saving" exceeds life-cycle saving (that would have taken place in the absence of lifetime uncertainty), lending further support to the notion that the perfect-certainty version of the life-cycle model provides an inadequate explanation of observed saving behavior. Second, the introduction of an actuarially fair social security system leads to a significant partial equilibrium increase in lifetime consumption and welfare, accompanied by a reduction in the capital stock.The increase in lifetime welfare is reduced, however,and in many cases eliminated, when borrowing restrictions are imposed.Third, extending the model to general equilibrium, we find that the partial equilibrium gains in lifetime welfare from participation in social security are offset by the interaction of higher steady-state interest rates and binding liquidity constraints. Finally, replacing the proportional payroll tax with a progressive tax (essentially a linear tax with an exemption), we show that age-specific tax schemes can restore much of the potential gain from introducing social security.
Ground Measurements of the Shock-Wave Noise from Airplanes in Level Flight at Mach Numbers to 1.4 and at Altitudes to 45000 Feet
Time histories of noise pressures near ground level were measured during flight tests of fighter-type airplanes over fairly flat, partly wooded terrain in the e Mach number range between 1.13 and 1.4 and at altitudes from 25,000 to 45,000 feet. Atmospheric soundings and radar tracking studies were made for correlation with the measured noise data. The measured and calculated values of the pressure rise across the shock wave were generally in good agreement. There is a tendency for the theory to overestimate the pressure at locations remote from the track and to underestimate the pressures for conditions of high tailwind at altitude. The measured values of ground-reflection factor averaged about 1.8 f or the surface tested as compared to a theoretical value of 2.0. P o booms were measured in all cases. The observers also generally reported two booms; although, in some cases, only one boom was reported. The shock-wave noise associated with some of the flight tests was judged to be objectionable by ground observers, and in one case the cracking of a plate-glass store window was correlated in time with the passage of the airplane at an altitude of 25,000 feet
Liquidity Constraints, Fiscal Policy, and Consumption
macroeconomics, liquidity constraints, fiscal policy, and consumption
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