REITs and Idiosyncratic Risk

This study examines various determinants of idiosyncratic risk from the perspective of un-diversified REIT investors, managers holding options, other option holders, and arbitrageurs. Since real estate investment trusts (REITs) enjoy a unique organizational structure and tax status, the relevant determinants derived from the two-stage regression model are different from other industrial firms. Results suggest that efficiency, liquidity and earnings variability are the important determinants of idiosyncratic risk, whereas size and capital do not

A re-analysis of the spectrum of 2206-199

Recently Pettini, Hunstead, Smith and Mar, (PHSM 1991) performed an analysis of the Ly-alpha forest of QSO 2206-199N at very high resolution. On the basis of their observations they concluded that most Doppler parameters b = (square root of 2)(sigma) of Ly-alpha forest lines are below 22 km/s, with a range down to a few km/s and a median of 17 km/s. They also found a strong intrinsic correlation between Doppler parameter b and column density N. These results are in contrast to those of a similar study by Carswell, Lanzetta, Parnell, and Webb (CLPW 1991) at comparable resolution with the same instruments, who find that most of the Ly-alpha lines towards QSO 1100-264 have Doppler parameters above 15 km/s (median b = 34 km/s), and that there is no significant correlation between b and N. Whilst an intrinsic difference between the lines of sight to 2206-199 and to other QSO's can not be excluded a priori, previous disagreement between Doppler parameter estimates obtained by both groups pointed to a potential difference in estimation techniques and in the interpretation of the results. To investigate this possibility, the AAT/UCLES spectrum of 2206-199 obtained by PHSM were reanalyzed. The spectrum was extracted from the raw data and determined the line parameters using the method described by CLPW

Stationarity and Co-Integration in Systems with Three National Real Estate Indices

This study examines the stochastic properties of the commercial real estate wealth indices for three countries (the U.S., Canada, and the U.K.) and for several property types (aggregate, office, retail, and industrial). Each of the indices is tested for a unit root and all series are found to be nonstationary. Furthermore, all indices also indicate the presence of both drift and trend. The results are strongest when the indices are tested in real estate and exchange rate-adjusted form. Application of Johansen's model indicates that the system for the three countries shows evidence of co-integration for the aggregate, retail, office, and industrial properties. Again, the evidence is the strongest when the indices are tested in real and exchange rate-adjusted form. Hence, it is conceivable that inflationary expectations may be the factor that provides the common linkage between commercial real estate across national boundaries.

The Deuterium Abundance in the z=0.7 absorber towards QSO PG1718+4807

We report a further analysis of the ratio of deuterium to hydrogen (D/H) using HST spectra of the z=0.701 Lyman limit system towards the QSO PG1718+481. Initial analyses of this absorber found it gave a high D/H value, 1.8 - 3.1 \times 10^{-4} (Webb et al. 1998), inconsistent with several higher redshift measurements. It is thus important to critically examine this measurement. By analysing the velocity widths of the DI, HI and metal lines present in this system, Kirkman et al. (2001) report that the additional absorption in the blue wing of the lya line can not be DI, with a confidence level of 98%. Here we present a more detailed analysis, taking into account possible wavelength shifts between the three sets of HST spectra used in the analysis. We find that the constraints on this system are not as strong as those claimed by Kirkman et al. The discrepancy between the parameters of the blue wing absorption and the parameters expected for DI is marginally worse than 1 sigma. Tytler et al.(1999) commented on the first analysis of Webb et al.(1997,1998), reporting the presence of a contaminating lower redshift Lyman limit system, with log[N(HI)] = 16.7 at z=0.602, which biases the N(HI) estimate for the main system. Here we show that this absorber actually has log[N(HI)] < 14.6 and does not impact on the estimate of N(HI) in the system of interest at z = 0.701. The purpose of the present paper is to highlight important aspects of the analysis which were not explored in previous studies, and hence help refine the methods used in future analyses of D/H in quasar spectra.Comment: 11 pages, 9 figures. Accepted by MNRA

Gypsy moths and American dog ticks: Space partners

An experiment intended for the space shuttle and designed to investigate the effects of weightlessness and total darkness on gypsy moth eggs and engorged American dog ticks is described. The objectives are: (1) to reevaluate the effects of zero gravity on the termination of diapause/hibernation of embryonated gypsy moth eggs, (2) to determine the effect of zero gravity on the ovipositions and subsequent hatch from engorged female American dog ticks that have been induced to diapause in the laboratory, and (3) to determine whether morphological or biochemical changes occur in the insects under examination. Results will be compared with those from a similar experiment conducted on Skylab 4

A Nonparametric Variance-Ratio Test of the Behavior of U.K. Real Estate and Construction Indices

This study utilizes tests based on ranks and signs suggested by Wright (2000), in addition to the traditional variance-ratio test, to examine the behavior of United Kingdom real estate and construction security indices. The results suggest a positive dependence in the index return series and provide a strong rejection of the random walk hypothesis for the two U.K. index series examined in this study. Thus, the efficient market hypothesis (EMH) is not confirmed for these real estate securities indices in the U.K.variance ratio; heteroskedasticity; stock index; random walk; ranks; signsJournal: International Real Estate Review

Hydrodynamic stability of swimming in ostraciid fishes: role of the carapace in the smooth trunkfish Lactophrys triqueter (Teleostei: Ostraciidae)

The hydrodynamic bases for the stability of locomotory motions in fishes are poorly understood, even for those fishes, such as the rigid-bodied smooth trunkfish Lactophrys triqueter, that exhibit unusually small amplitude recoil movements during rectilinear swimming. We have studied the role played by the bony carapace of the smooth trunkfish in generating trimming forces that self-correct for instabilities. The flow patterns, forces and moments on and around anatomically exact, smooth trunkfish models positioned at both pitching and yawing angles of attack were investigated using three methods: digital particle image velocimetry (DPIV), pressure distribution measurements, and force balance measurements. Models positioned at various pitching angles of attack within a flow tunnel produced well-developed counter-rotating vortices along the ventro-lateral keels. The vortices developed first at the anterior edges of the ventro-lateral keels, grew posteriorly along the carapace, and reached maximum circulation at the posterior edge of the carapace. The vortical flow increased in strength as pitching angles of attack deviated from 0°, and was located above the keels at positive angles of attack and below them at negative angles of attack. Variation of yawing angles of attack resulted in prominent dorsal and ventral vortices developing at far-field locations of the carapace; far-field vortices intensified posteriorly and as angles of attack deviated from 0°. Pressure distribution results were consistent with the DPIV findings, with areas of low pressure correlating well with regions of attached, concentrated vorticity. Lift coefficients of boxfish models were similar to lift coefficients of delta wings, devices that also generate lift through vortex generation. Furthermore, nose-down and nose-up pitching moments about the center of mass were detected at positive and negative pitching angles of attack, respectively. The three complementary experimental approaches all indicate that the carapace of the smooth trunkfish effectively generates self-correcting forces for pitching and yawing motions — a characteristic that is advantageous for the highly variable velocity fields experienced by trunkfish in their complex aquatic environment. All important morphological features of the carapace contribute to producing the hydrodynamic stability of swimming trajectories in this species