Business Cycle Asymmetries: Characterisationand Testing Based on Markov-Switching Autoregression.

We propose testing for business cycle asymmetries in Markov-switching autoregressive (MS-AR) models. We derive the parametric restrictions on MS-AR models that rule out types of asymmetries such as deepness, steepness, and sharpness, and set out a testing procedure based on Wald statistics which have standard asymptotic. For a two-regime model, such as that popularized by Hamilton (1989), we show that deepness implies sharpness (and vice versa) while the process is always non-steep. We illustrate with two and three-state MS models of US GNP growth, and with models of US output and employment. Our findings are compared with those obtained from standard non-parametric tests.BUSINESS CYCLES ; TESTS

The Stairway to the Top: The Remuneration of Academic Executives

Australian universities have in recent times been undergoing a substantial transformation in the way in which they are managed. They have moved away from the (British-based) traditional collegiate model to one in which professional managers play a centre-stage role. This paper investigates an important element of the managerialism at Australian universities, the market for what we call “academic executives” (AEs). We analyse the remuneration of the top AEs at Australian universities over the past six years and show that institutional size is a dominant driving factor of remuneration, as has been found with compensation of CEOs in the private sector. We also find the pay-size elasticity to be about 0.25 and is the same for both the university and private sectors; and remarkably, this value has also been found in previous studies on executive remuneration for the US and the UK. The remuneration schedule for the university sector is about half as steep as that for the private sector, suggesting that it is a much harder climb to the top of the corporate ladder. We analyse the structure of remuneration among AEs and the Group of Eight universities are found to have a pay parity structure that is closest to that for the private sector.

The Pay Parity Matrix A Toll For Analysing The Structure of Pay

This paper introduces a new tool for measuring relative pay within organisations, which we call the “pay parity (PP) matrix” and discusses its advantages and useful properties. The PP matrix allows us to conveniently measure, and draw inferences about, the nature of the whole remuneration schedule, such as its gradient and smoothness. We illustrate the application of the PP matrix by using data on the remuneration of academic executives. This tool has wider uses whenever matrix comparisons are involved.

Quantile Forecasts of Daily Exchange Rate Returns from Forecasts of Realized Volatility

Quantile forecasts are central to risk management decisions because of the widespread use of Value-at-Risk. A quantile forecast is the product of two factors : the model used to forecast volatility, and the method of computing quantiles from the volatility forecasts. In this paper we calculate and evaluate quantile forecasts of the daily exchange rate returns of five currencies. The forecasting models that have been used in recent analyses of the predictability of daily realized volatility permit a comparison of the predictive power of different measures of intraday variation and intraday returns in forecasting exchange rate variability. The methods of computing quantile forecasts include making distributional assumptions for future daily returns as well as using the empirical distribution of predicted standardized returns with both rolling and recursive samples. Our main ?ndings are that the HAR model provides more accurate volatility and quantile forecasts for currencies which experience shifts in volatility, such as the Canadian dollar, and that the use of the empirical distribution to calculate quantiles can improve forecasts when there are shifts.realized volatility ; quantile forecasting ; MIDAS ; HAR ; exchange rates

Bioaccumulation of heavy metals by brown trout (Salmo trutta) in the Arkansas River: importance of food chain transfer

December, 1992.Includes bibliographical references (pages 13-14).This study examined uptake and transfer of heavy metals form benthic invertebrates to brown trout in the Arkansas River. Metals in water, aufwuchs, benthic invertebrates, and fish were measured at stations upstream and downstream from California Gulch (GC). Aufwuchs and benthic invertebrates were highly contaminated by heavy metals downstream from California Gulch. The diet of brown trout at the Arkansas River was dominated by benthic invertebrates. These accounted for 40 to 95 percent of the diet of the brown trout. Differences in prey availability between upstream and downstream resulted in the differences. Ephemeroptera comprised a greater portion of the diet of the fish collected upstream from GC, whereas metal-tolerant organisms were more common in the diet of fish from downstream. Elevated metal levels in water and invertebrates downstream resulted in increased metals in gill and gut tissue; however, metal concentrations in brown trout liver and kidney tissue were generally similar both upstream and downstream. The data suggest that fish regulated metal accumulation. The implications of these findings for the recovery of brown trout populations at the Arkansas River are discussed.Grant no. 14-08-0001-2008, Project no. 10; financed in part by the U.S. Dept. of the Interior, Geological Survey, through the Colorado Water Resources Research Institute

Excitations in confined helium

We design models for helium in matrices like aerogel, Vycor or Geltech from a manifestly microscopic point of view. For that purpose, we calculate the dynamic structure function of 4He on Si substrates and between two Si walls as a function of energy, momentum transfer, and the scattering angle. The angle--averaged results are in good agreement with the neutron scattering data; the remaining differences can be attributed to the simplified model used here for the complex pore structure of the materials. A focus of the present work is the detailed identification of coexisting layer modes and bulk--like excitations, and, in the case of thick films, ripplon excitations. Involving essentially two--dimensional motion of atoms, the layer modes are sensitive to the scattering angle.Comment: Phys. Rev. B (2003, in press

Nuclear gas dynamics in Arp 220 - sub-kiloparsec scale atomic hydrogen disks

We present new, high angular resolution (~0.22") MERLIN observations of neutral hydrogen (HI) absorption and 21-cm radio continuum emission across the central ~900 parsecs of the ultraluminous infrared galaxy, Arp220. Spatially resolved HI absorption is detected against the morphologically complex and extended 21-cm radio continuum emission, consistent with two counterrotating disks of neutral hydrogen, with a small bridge of gas connecting the two. We propose a merger model in which the two nuclei represent the galaxy cores which have survived the initial encounter and are now in the final stages of merging, similar to conclusions drawn from previous CO studies (Sakamoto, Scoville & Yun 1999). However, we suggest that instead of being coplanar with the main CO disk (in which the eastern nucleus is embedded), the western nucleus lies above it and, as suggested by bridge of HI connecting the two nuclei, will soon complete its final merger with the main disk. We suggest that the collection of radio supernovae (RSN) detected in VLBA studies in the more compact western nucleus represent the second burst of star formation associated with this final merger stage and that free-free absorption due to ionised gas in the bulge-like component can account for the observed RSN distribution. (Abridged)Comment: 26 pages including 8 figures and 1 table; accepted for publication in Ap

Ground-based detection of a cloud of methanol from Enceladus: When is a biomarker not a biomarker?

Saturn's moon Enceladus has vents emerging from a sub-surface ocean, offering unique probes into the liquid environment. These vents drain into the larger neutral torus in orbit around Saturn. We present a methanol (CH3OH) detection observed with IRAM 30-m from 2008 along the line-of-sight through Saturn's E-ring. Additionally, we also present supporting observations from the Herschel public archive of water (ortho-H2O; 1669.9 GHz) from 2012 at a similar elongation and line-of-sight. The CH3OH 5(1,1)-4(1,1) transition was detected at 5.9 sigma confidence. The line has 0.43 km/s width and is offset by +8.1 km/s in the moon's reference frame. Radiative transfer models allow for gas cloud dimensions from 1750 km up to the telescope beam diameter ~73000 km. Taking into account the CH3OH lifetime against solar photodissociation and the redshifted line velocity, there are two possible explanations for the CH3OH emission: methanol is primarily a secondary product of chemical interactions within the neutral torus that (1) spreads outward throughout the E-ring or (2) originates from a compact, confined gas cloud lagging Enceladus by several km/s. We find either scenario to be consistent with significant redshifted H2O emission (4 sigma) measured from the Herschel public archive. The measured CH3OH:H2O abundance (> 0.5 per cent) significantly exceeds the observed abundance in the direct vicinity of the vents (~0.01 per cent), suggesting CH3OH is likely chemically processed within the gas cloud with methane (CH4) as its parent species.Comment: 16 pages, 4 figures, accepted for publication in the International Journal of Astrobiology (IJA

Significant but Unheralded Growth of Large Externship Programs

Law schools have offered student externships for several decades. The number of participating students has fluctuated over time. At first, more law students participated in externships than in in-house clinics, but that changed in the 1980s and remained consistent for many years. Starting in the early- to mid-1990s, externship enrollment surpassed in-house-clinic participation again and has continued to increase in the past decade, each year widening the gap between these two primary forms of practice-based experiential learning. Today, externships have never been more important as a means of providing practical legal education to the current generation of law students