20 research outputs found
H-ATLAS/GAMA: magnification bias tomography. Astrophysical constraints above ~1 arcmin
An unambiguous manifestation of the magnification bias is the cross-correlation between two source samples with non-overlapping redshift distributions. In this work we measure and study the cross-correlation signal between a foreground sample of GAMA galaxies with spectroscopic redshifts in the range 0.2<z<0.8, and a background sample of H-ATLAS galaxies with photometric redshifts gsim1.2. It constitutes a substantial improvement over the cross-correlation measurements made by Gonzalez-Nuevo et al. (2014) with updated catalogues and wider area (with S/Ngsim 5 below 10 arcmin and reaching S/N~ 20 below 30 arcsec). The better statistics allow us to split the sample in different redshift bins and to perform a tomographic analysis (with S/Ngsim 3 below 10 arcmin and reaching S/N~ 15 below 30 arcsec). Moreover, we implement a halo model to extract astrophysical information about the background galaxies and the deflectors that are producing the lensing link between the foreground (lenses) and background (sources) samples. In the case of the sources, we find typical mass values in agreement with previous studies: a minimum halo mass to host a central galaxy, Mmin~ 1012.26 M⊙, and a pivot halo mass to have at least one sub-halo satellite, M1~ 1012.84 M⊙. However, the lenses are massive galaxies or even galaxy groups/clusters, with minimum mass of Mminlens~ 1013.06 M⊙. Above a mass of M1lens~ 1014.57 M⊙ they contain at least one additional satellite galaxy which contributes to the lensing effect. The tomographic analysis shows that, while M1lens is almost redshift independent, there is a clear evolution of increase Mminlens with redshift in agreement with theoretical estimations. Finally, the halo modeling allows us to identify a strong lensing contribution to the cross-correlation for angular scales below 30 arcsec. This interpretation is supported by the results of basic but effective simulations
National wage-rate claims and settlements - II. An exploratory study of some possible determinants of claims and settlements
What are the determinants of the level of trades unions' wage-rate claims? To answer this question, a range of simplified models is examined. One set of these models pictures bargainers being influenced when setting claims by looking backward to past variations in the cost of living, past changes in general wage-rates, the gap between the union's claims and settlements in previous bargaining rounds, and the time since their last settlement. A second set pictures bargainers looking forward, as some versions of expectation theory suggest, to rationally expected future price increases, expected future wage-rate changes, and the time to the next claim. Another model pictures bargainers tactically setting claims beyond their realistic expectations in anticipation of settlements being forced at a level below their stated claims. Applications of these models to nine groups of workers represented by five large British trades unions over the period 1947 to 1970 shows that claims appear to be more influenced (though only weakly) by retrospective than by prospective price increases (so there is little support for monetarists' rational expectations theory of inflation) though they appear to be more influenced by prospective than by retrospective increases in general wage-rates. Claims are uninfluenced by the gap between past claims and settlements or by time variables, but there is strong support for the bargaining tactics hypothesis
British Evidence on the Employment Effects of Profit Sharing
A sample of British firms with diverse sharing arrangements is used to investigate the effects of profit sharing on employment levels. Employment effects are sometimes significant, but this depends upon the measure of profit sharing, how the dynamics are modeled, and whether measures of employee participation in decision making are included in the estimating equation. Using a continuous measure of profit sharing, employment effects, which typically range from -6 per cent to 6 per cent, are much more modest than those obtained by some other researchers. Most findings are not dramatically affected by estimating the specifications separately for discrete time periods, for individual industries, or for larger firms