Reserve requirements: A modern perspective

The discussion in many money and banking textbooks would suggest that the Federal Reserve requires depository institutions to hold a minimum level of non-interest-earning reserves because (1) reserve requirements are a monetary policy tool that allows the Fed to expand the money supply and lower interest rates, and (2) reserve requirements improve the safety and soundness of depository institutions. This article argues that this "conventional wisdom" view is too narrow. ; The Fed often uses reserve requirement changes, the authors contend, to achieve non-monetary-policy objectives, as it did in 1992 to improve the profitability of depository institutions and ease the credit crunch of that time. The authors also challenge the notion that higher reserve requirements necessarily lead to greater safety and lower default risk for depository institutions. ; The article examines the relationship between reserve requirement changes and monetary policy, with the aim of demonstrating the recent, limited usefulness of reserve requirements as a monetary policy tool. The article proposes a more modern view of reserve requirements as a tax on depository institutions, ponders who really bears this tax, and summarizes a large and growing literature suggesting that perceived bank profitability is inversely affected by announced changes in reserve requirement ratios. The article also provides new evidence that the 1992 reserve requirement reductions were not associated with an increase in default risk for financial institutions that issue reservable instruments, as the conventional view would suggest.Monetary policy ; Financial institutions ; Bank reserves

Design definition of a mechanical capacitor

A design study and analyses of a 10 kW-hr, 15 kW mechanical capacitor system was studied. It was determined that magnetically supported wheels constructed of advanced composites have the potential for high energy density and high power density. Structural concepts are analyzed that yield the highest energy density of any structural design yet reported. Particular attention was paid to the problem of 'friction' caused by magnetic and I to the second power R losses in the suspension and motor-generator subsystems, and low design friction levels have been achieved. The potentially long shelf life of this system, and the absence of wearing parts, provide superior performance over conventional flywheels supported with mechanical bearings. Costs and economies of energy storage wheels were reviewed briefly

Classical Functional Bethe Ansatz for SL(N)SL(N): separation of variables for the magnetic chain

The Functional Bethe Ansatz (FBA) proposed by Sklyanin is a method which gives separation variables for systems for which an $R$-matrix is known. Previously the FBA was only known for $SL(2)$ and $SL(3)$ (and associated) $R$-matrices. In this paper I advance Sklyanin's program by giving the FBA for certain systems with $SL(N)$ $R$-matrices. This is achieved by constructing rational functions \A(u) and \B(u) of the matrix elements of $T(u)$, so that, in the generic case, the zeros $x_i$ of \B(u) are the separation coordinates and the P_i=\A(x_i) provide their conjugate momenta. The method is illustrated with the magnetic chain and the Gaudin model, and its wider applicability is discussed.Comment: 14pp LaTex,DAMTP 94-1

The Effects of Children's Time Use and Home and Neighborhood Quality on their Body Weight and Cognitive/Behavioral Development

We estimate a directional distance function to assess the impacts of multiple time-varying parent and child inputs on a cluster of jointly produced child outcomes for children aged 7 to 13 years. The directional distance function specification avoids several well-known empirical problems associated with analysis of household production data, namely, the need to aggregate inputs and outputs, assume separability among inputs and outputs, or estimate reduced form equations. Using a balanced panel of families from the National Longitudinal Survey of Youth-Child Sample for 1996 to 2000, we assess the marginal contributions of home and neighborhood environmental quality and children's time allocations, on their math and reading performance, behavior problems, and body mass index. We also measure productivity growth, technical change, efficiency change, and technical efficiency for production of child outcomes. Our results indicate significant jointness among good and bad child outcomes. Significant improvements in children's good outcomes and reductions in bad outcomes are also associated with a better home and parent perceived neighborhood environment, Head Start participation, and increased family time spent together during meals. Children's productivity growth is found to be highest at age 8 years and diminishes thereafter.Health Economics and Policy, Labor and Human Capital,

Improvement of experimental testing and network training conditions with genome-wide microarrays for more accurate predictions of drug gene targets

BACKGROUND: Genome-wide microarrays have been useful for predicting chemical-genetic interactions at the gene level. However, interpreting genome-wide microarray results can be overwhelming due to the vast output of gene expression data combined with off-target transcriptional responses many times induced by a drug treatment. This study demonstrates how experimental and computational methods can interact with each other, to arrive at more accurate predictions of drug-induced perturbations. We present a two-stage strategy that links microarray experimental testing and network training conditions to predict gene perturbations for a drug with a known mechanism of action in a well-studied organism. RESULTS: S. cerevisiae cells were treated with the antifungal, fluconazole, and expression profiling was conducted under different biological conditions using Affymetrix genome-wide microarrays. Transcripts were filtered with a formal network-based method, sparse simultaneous equation models and Lasso regression (SSEM-Lasso), under different network training conditions. Gene expression results were evaluated using both gene set and single gene target analyses, and the drug’s transcriptional effects were narrowed first by pathway and then by individual genes. Variables included: (i) Testing conditions – exposure time and concentration and (ii) Network training conditions – training compendium modifications. Two analyses of SSEM-Lasso output – gene set and single gene – were conducted to gain a better understanding of how SSEM-Lasso predicts perturbation targets. CONCLUSIONS: This study demonstrates that genome-wide microarrays can be optimized using a two-stage strategy for a more in-depth understanding of how a cell manifests biological reactions to a drug treatment at the transcription level. Additionally, a more detailed understanding of how the statistical model, SSEM-Lasso, propagates perturbations through a network of gene regulatory interactions is achieved.Published versio

Models for application of radiation boundary condition for MHD waves in collapse calculations

The problem of reflection of magnetohydrodynamic (MHD) waves at the boundary of a numerical grid has to be resolved in order to obtain reliable results for the end state of the (isothermal) collapse of a rotating, magnetic protostellar cloud. Since the goal of investigating magnetic braking in collapse simulations is to see if the transport of angular momentum via alfven waves is large enough to solve the angular momentum problem an approximation that artificially suppresses large amplitudes in the MHD waves can be self-defeating. For this reason, four alternate methods of handling reflected waves where no assumptions are made regarding the amplitudes of the waves were investigated. In order to study this problem (of reflection) without interference from other effects these methods were tried on two simpler cases. The four methods are discussed

Convective instability and mass transport of diffusion layers in a Hele-Shaw geometry

We consider experimentally the instability and mass transport of a porous-medium flow in a Hele-Shaw geometry. In an initially stable configuration, a lighter fluid (water) is located over a heavier fluid (propylene glycol). The fluids mix via diffusion with some regions of the resulting mixture being heavier than either pure fluid. Density-driven convection occurs with downward penetrating dense fingers that transport mass much more effectively than diffusion alone. We investigate the initial instability and the quasi steady state. The convective time and velocity scales, finger width, wave number selection, and normalized mass transport are determined for 6,000<Ra<90,000. The results have important implications for determining the time scales and rates of dissolution trapping of carbon dioxide in brine aquifers proposed as possible geologic repositories for sequestering carbon dioxide.Comment: 4 page, 3 figure

Nonlinear supratransmission and bistability in the Fermi-Pasta-Ulam model

The recently discovered phenomenon of nonlinear supratransmission consists in a sudden increase of the amplitude of a transmitted wave triggered by the excitation of nonlinear localized modes of the medium. We examine this process for the Fermi-Pasta-Ulam chain, sinusoidally driven at one edge and damped at the other. The supratransmission regime occurs for driving frequencies above the upper band-edge and originates from direct moving discrete breather creation. We derive approximate analytical estimates of the supratransmission threshold, which are in excellent agreement with numerics. When analysing the long-time behavior, we discover that, below the supratransmission threshold, a conducting stationary state coexists with the insulating one. We explain the bistable nature of the energy flux in terms of the excitation of quasi-harmonic extended waves. This leads to the analytical calculation of a lower-transmission threshold which is also in reasonable agreement with numerical experiments.Comment: 8 pages, 9 figures. Phys. Rev. E (accepted

The Saccharomyces cerevisiae SEC14 Gene Encodes a Cytosolic Factor That Is Required for Transport of Secretory Proteins from the Yeast Golgi Complex

We have obtained and characterized a genomic clone of SEC14, a Saccharomyces cerevisiae gene whose product is required for export of yeast secretory proteins from the Golgi complex. Gene disruption experiments indicated that SEC14 is an essential gene for yeast vegetative growth. Nucleotide sequence analysis revealed the presence of an intron within the SEC14 structural gene, and predicted the synthesis of a hydrophilic polypeptide of 35 kD in molecular mass. In confirmation, immunoprecipitation experiments demonstrated SEC14p to be an unglycosylated polypeptide, with an apparent molecular mass of some 37 kD, that behaved predominantly as a cytosolic protein in subcellular fractionation experiments. These data were consistent with the notion that SEC14p is a cytosolic factor that promotes protein export from yeast Golgi. Additional radiolabeling experiments also revealed the presence of SEC14p-related polypeptides in extracts prepared from the yeasts Kluyveromyces lactis and Schizosaccharomyces pombe. Furthermore, the K. lactis SEC14p was able to functionally complement S. cerevisiae sec14ts defects. These data suggested a degree of conservation of SEC14p structure and function in these yeasts species