Relativism and Objectivism about Truth

A short paper discussing and critiquing common claims that "truth is relative.

The Quality of Health Care Providers

Obtaining better information on the quality of health care providers is one of the most pressing issues in health policy today. In this paper we (1) develop a new method for measuring quality of care that overcomes the key limitations of available quality measures, and (2) apply this method to estimating the quality of hospital care for elderly patients with heart disease. Our approach optimally combines information from all available current and past quality indicators in order to more accurately estimate and forecast each provider's quality level. For patients with heart disease, the method is able to predict and forecast differences in patient outcomes across hospitals remarkably well - far better than existing methods. Our approach also provides an empirical basis for choosing among potential quality indicators. In particular, we find that differences across hospitals in short-term mortality rates following a heart attack, adjusted for patient demographics, are excellent indicators of quality of care: They vary dramatically across hospitals, are persistent over time, are highly correlated with alternative quality indicators, and are highly correlated with mortality rates that adjust more extensively for patient severity. Thus, comparing quality of care across providers may be far more feasible than many now believe.

"Sample Variance" in Small-Scale CMB Anisotropy Experiments

We discuss the effects of finite sky coverage and the uncertainty in extracting information about the power spectrum from experiments on small angular scales. In general the cosmic variance is enhanced by a factor of $4\pi/A$, where $A$ is the solid angle sampled by the experiment. As a rough guide, an experiment with sensitivity peaking at the $\ell$th multipole has to cover \simgt\ell independent patches to have a lower ``sample variance'' than for a whole-sky measurement of the quadrupole. Our approach gives a relatively simple way of attaching an error bar to the theoretical prediction for a particular experiment, and thereby comparing theories with experimental results, without the need for computationally-intensive Maximum Likelihood or Monte Carlo calculations.Comment: 6 pages in Plain TeX with 1 postscript figure appende

Irrigation management transfer in the Columbia Basin: lessons and international implications

Irrigation management, Farmer managed irrigation systems, Privatization, Irrigation efficiency, Irrigation effects, Project appraisal, Financing, Developing countries, Farm Management, Financial Economics,

Comparison of structural performance of one- and two-bay rotary joints for truss applications

The structural performance of one- and two-bay large-diameter discrete-bearing rotary joints was addressed for application to truss-beam structures such as the Space Station Freedom. Finite element analyses are performed to determine values for rotary joint parameters that give the same bending vibration frequency as the parent truss beam. The structural masses and maximum internal loads of these joints are compared to determine their relative structural efficiency. Results indicate that no significant difference exists in the masse of one- and two-bay rotary joints. This conclusion is reinforced with closed-form calculations of rotary joint structural efficiency in extension. Also, transition truss-member loads are higher in the one-bay rotary joint. However, because of the increased buckling strength of these members, the external load-carrying capability of the one-bay concept is higher than that of the two-bay concept

Capitalization of Capital Gains Taxes: Evidence from Stock Price Reactions to the 1997 Rate Reduction

We empirically document that stock prices moved inversely with dividend yields during the May, 1997 week, when the White House and Congress agreed on a budget accord that included a reduction in the capital gains tax rate. The share prices of firms not currently paying dividends increased approximately 6 percentage points more over a five-day window than the share prices of other firms. Among firms paying dividends, the change in share prices was decreasing in dividend yields. The results are consistent with at least two related explanations. First, to the extent a stock's returns are expected to be taxed as capital gains, a reduction in the expected capital gains tax rate enhances the attractiveness of the investment to investors. Second, to the extent a firm's stock is held by shareholders subject to the capital gains tax, a reduction in the expected capital gains tax rate increases its market value. The findings present evidence consistent with neither a sell-off of appreciated securities following the rate reduction nor a reduction in the compensation for capital gains taxes that selling shareholders demand from buyers. The upward price pressure around the accord dominated any downward price pressure imposed by these factors.

Effect of chloride on the chemical conversion of nitrate to nitrous oxide for δ15N analysis

We investigate the influence of chloride concentration on the performance of the chemical reduction method for measurement of the nitrogen isotopic ratio (δ15N) in NO3− in natural waters (McIlvin and Altabet, 2005). In this method, NO3− is first reduced to NO2− using activated cadmium metal, with further reduction to N2O using sodium azide in an acetic acid buffer. N2O is introduced into an isotope ratio mass spectrometer (IRMS) for isotopic measurement. Previously, it was recognized that the presence of halides was necessary for the speed and efficiency of the second step but not thought to be important for the first step. Whereas quantitative Cd reduction of NO3− to NO2− had been noted for seawater samples, here we report, for freshwater and low‐salinity (S 99%) reduction of NO3− to NO2− as well as stable δ15N values that closely matched expected values for standards (within 0.3‰ of standard value). The positive effect of NaCl is likely due to a decrease in free Cd2+ produced over the course of the reaction due to formation of CdCl2