Review of Heavy Hadron Spectroscopy

The status of some of the recently discovered heavy hadrons is presented.Comment: 6 pages, plenary talk at International Conference on QCD and Hadronic Physics, Beijing, June 200

Aspects of Confinement: a Brief Review

A brief and biased overview of the phenomenon of confinement in QCD is presented in three parts: (1) the definition of confinement, (2) properties of confinement, (3) ideas of confinement. The second part chiefly consists of a brief review of recent lattice computations related to confinement while the third summarizes some of the current analytical approaches to understanding confinement. These include the Dyson-Schwinger formalism in Landau gauge, Hamiltonian QCD in Coulomb gauge, and the vortex picture of confinement.Comment: 10 pages, 6 eps figures. Plenary talk at Hadron 2003, Aschaffenburg, German

XYZ States: Theory Overview

Various ideas associated with exotic hadrons, and hadronic structure in general, are briefly reviewed.Comment: 6 pages, Proceedings of Hadron201

Molecular Interpretation of the X(3872)

The discovery of the X(3872) in the 3\pi J/\psi mode is compelling evidence for its molecular nature. A successful prediction of this decay mode and other predictions are reviewed here.Comment: 3 pages, ICHEP proceeding

Optimal Nonlinear Policy: Signal Extraction with a Non-Normal Prior

The literature on optimal monetary policy typically makes three major assumptions: 1) policymakers’ preferences are quadratic, 2) the economy is linear, and 3) stochastic shocks and policymakers’ prior beliefs about unobserved variables are normally distributed. This paper relaxes the third assumption and explores its implications for optimal policy. The separation principle continues to hold in this framework, allowing for tractability and application to forward-looking models, but policymakers’ beliefs are no longer updated in a linear fashion, allowing for plausible nonlinearities in optimal policy. We consider in particular a class of models in which policymakers’ priors about the natural rate of unemployment are diffuse in a region around the mean. When this is the case, it is optimal for policy to respond cautiously to small surprises in the observed unemployment rate, but become increasingly aggressive at the margin. These features of optimal policy match statements by Federal Reserve officials and the behavior of the Fed in the 1990snonlinear policy, optimal filtering, signal extraction, learning, non-normal priors

Let’s twist again: a high-frequency event-study analysis of operation twist and its implications for QE2

This paper undertakes a modern event-study analysis of Operation Twist and compares its effects to those that should be expected for the recent quantitative policy announced by the Federal Reserve, dubbed "QE2". We first show that Operation Twist and QE2 are similar in magnitude. We identify six significant, discrete announcements in the course of Operation Twist that potentially could have had a major effect on financial markets, and show that four did have statistically significant effects. The cumulative effect of these six announcements on longer-term Treasury yields is highly statistically significant but moderate, amounting to about 15 basis points. This estimate is consistent both with Modigliani and Sutch’s (1966) time series analysis and with the lower end of empirical estimates of Treasury supply effects in the literature.Monetary policy

Real wage cyclicality in the PSID

Previous studies of real wage cyclicality have made only sparing use of the microdata detail that is available in the Panel Study of Income Dynamics (PSID). The present paper brings to bear this additional detail to investigate the robustness of previous results and to examine whether there are important cross-sectional and demographic differences in wage cyclicality. Although real wages were procyclical across the entire distribution of workers from 1967 to 1991, the wages of lower-income, younger, and less-educated workers exhibited greater procyclicality. However, workers' straight-time hourly pay rates have been acyclical, suggesting that more variable pay margins such as bonuses, overtime, late shift premia, and commissions have played a substantial if not primary role in generating procyclicality.Wages ; Labor market