Unlikely Estimates of the Ex Ante Real Interest Rate: Another Dismal Performance from the Dismal Science1

The ex ante real rate of interest is one of the most important concepts in economics and finance. Because the universally-used Fisher theory of interest requires positive ex ante real interest rates, empirical estimates of the ex ante real interest rate derived from the Fisher theory of interest should also be positive. Unfortunately, virtually all estimates of the ex ante real interest rate published in economic journals and textbooks or used in macroeconomic models and policy discussions for the past 35 years contain negative values for extended time periods and, thus, are theoretically flawed. Moreover, the procedures generally used to estimate ex ante real interest rates were shown to produce biased estimates of the ex ante real rate over 30 years ago. In this article, we document this puzzling chasm between the Fisherian theory that mandates positive ex ante real interest rates and the practice of macroeconomists who generate and use ex ante real interest rate estimates that violate this theory. We explore the reasons that this problem exists and assess some alternative approaches for estimating the ex ante real interest rate to determine whether they might resolve this problem.ex ante real interest rate, Fisher theory of interest, biased real interest rate estimates

The Effect of the Radial Pressure Gradient in Protoplanetary Disks on Planetesimal Formation

The streaming instability (SI) provides a promising mechanism for planetesimal formation because of its ability to concentrate solids into dense clumps. The degree of clumping strongly depends on the height-integrated solid to gas mass ratio Z in protoplanetary disks (PPDs). In this letter, we show that the magnitude of the radial pressure gradient (RPG) which drives the SI (characterized by $q\equiv{\eta}v_K/c_s$, where ${\eta}v_K$ is the reduction of Keplerian velocity due to the RPG and $c_s$ is the sound speed) also strongly affects clumping. We present local two-dimensional hybrid numerical simulations of aerodynamically coupled particles and gas in the midplane of PPDs. Magnetic fields and particle self-gravity are ignored. We explore three different RPG values appropriate for typical PPDs: $q=0.025, 0.05$ and 0.1. For each $q$ value, we consider four different particle size distributions ranging from sub millimeter to meter sizes and run simulations with solid abundance from Z=0.01 up to Z=0.07. We find that a small RPG strongly promotes particle clumping in that: 1) At fixed particle size distribution, the critical solid abundance $Z_{\rm crit}$ above which particle clumping occurs monotonically increases with $q$; 2) At fixed Z, strong clumping can occur for smaller particles when $q$ is smaller. Therefore, we expect planetesimals to form preferentially in regions of PPDs with a small RPG.Comment: 10 pages, submitted to ApJ

Thomas Hale Kreeger

The information found on Thomas Hale Kreeger1 suggests that he lead an obscure, average life even though he had in­herited land and money. He appeared in only one census, one city directory, and except for when his death was noted only once in the newspapers. His parents and grandparents (mother\u27s side) were different, active in business and the community.https://digitalcommons.georgiasouthern.edu/sav-bios-lane/1216/thumbnail.jp

Differences in work environment for staff as an explanation for variation in central line bundle compliance in intensive care units.

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) are a common and costly quality problem, and their prevention is a national priority. A decade ago, researchers identified an evidence-based bundle of practices that reduce CLABSIs. Compliance with this bundle remains low in many hospitals. PURPOSE: The aim of this study was to assess whether differences in core aspects of work environments-workload, quality of relationships, and prioritization of quality-are associated with variation in maximal CLABSI bundle compliance, that is, compliance 95%-100% of the time in intensive care units (ICUs). METHODOLOGY/APPROACH: A cross-sectional study of hospital medical-surgical ICUs in the United States was done. Data on work environment and bundle compliance were obtained from the Prevention of Nosocomial Infections and Cost-Effectiveness Refined Survey completed in 2011 by infection prevention directors, and data on ICU and hospital characteristics were obtained from the National Healthcare Safety Network. Factor and multilevel regression analyses were conducted. FINDINGS: Reasonable workload and prioritization of quality were positively associated with maximal CLABSI bundle compliance. High-quality relationships, although a significant predictor when evaluated apart from workload and prioritization of quality, had no significant effect after accounting for these two factors. PRACTICE IMPLICATIONS: Aspects of the staff work environment are associated with maximal CLABSI bundle compliance in ICUs. Our results suggest that hospitals can foster improvement in ensuring maximal CLABSI bundle compliance-a crucial precursor to reducing CLABSI infection rates-by establishing reasonable workloads and prioritizing quality

Oculometric Assessment of Mild Neural Impairment

For over 100 years, neurologists have used eye movements to identify neural impairment, disease, or injury. Prior to the age of modern imaging, qualitative assessment of eye movements was a critical, routine component of diagnosis and remains today a routine law-enforcement tool for detecting impaired driving due to drugs or alcohol. We will describe the application of a simple 5-minute oculomotor tracking task coupled with a broad range of quantitative analyses of high-resolution oculomotor measurements for the sensitive detection of sub-clinical neural impairment and for the potential differentiation of various causes. Specifically, we will show that there are distinct patterns of impairment across our set of oculometric parameters observed with brain trauma, sleep and circadian disruption, and alcohol consumption. Such differences could form the basis of a self-administered medical monitoring or diagnostic support tool

Quantum coherence in a ferromagnetic metal: time-dependent conductance fluctuations

Quantum coherence of electrons in ferromagnetic metals is difficult to assess experimentally. We report the first measurements of time-dependent universal conductance fluctuations in ferromagnetic metal (Ni$_{0.8}$Fe$_{0.2}$) nanostructures as a function of temperature and magnetic field strength and orientation. We find that the cooperon contribution to this quantum correction is suppressed, and that domain wall motion can be a source of coherence-enhanced conductance fluctuations. The fluctuations are more strongly temperature dependent than those in normal metals, hinting that an unusual dephasing mechanism may be at work.Comment: 5 pages, 4 figure