617 research outputs found
Does product market competition increase strike activity? Evidence from the UK
Although many studies have examined the effect of labour market characteristics, macroeconomic fluctuations and workplace-level factors on strike activity, much less is known about industry-level determinants of industrial conflict, and in particular the role of product market competition. I examine the effect of competition on strike activity using evidence from a natural experiment of policy reform, the introduction of cartel legislation in the UK in the late 1950s. My econometric analysis, which takes advantage of the fact that different industries were affected to varying degrees by cartel policy, establishes that both the number of strikes and the number of working days lost as a result of strikes increased significantly when competition intensified after the abolition of cartels. I propose an interpretation of these results with reference to theoretical models of bargaining with asymmetric information
The Comoving Infrared Luminosity Density: Domination of Cold Galaxies across 0<z<1
In this paper we examine the contribution of galaxies with different infrared
(IR) spectral energy distributions (SEDs) to the comoving infrared luminosity
density, a proxy for the comoving star formation rate (SFR) density. We
characterise galaxies as having either a cold or hot IR SED depending upon
whether the rest-frame wavelength of their peak IR energy output is above or
below 90um. Our work is based on a far-IR selected sample both in the local
Universe and at high redshift, the former consisting of IRAS 60um-selected
galaxies at z<0.07 and the latter of Spitzer 70um selected galaxies across
0.1<z<1. We find that the total IR luminosity densities for each
redshift/luminosity bin agree well with results derived from other deep
mid/far-IR surveys. At z<0.07 we observe the previously known results: that
moderate luminosity galaxies (L_IR<10^11 Lsun) dominate the total luminosity
density and that the fraction of cold galaxies decreases with increasing
luminosity, becoming negligible at the highest luminosities. Conversely, above
z=0.1 we find that luminous IR galaxies (L_IR>10^11 Lsun), the majority of
which are cold, dominate the IR luminosity density. We therefore infer that
cold galaxies dominate the IR luminosity density across the whole 0<z<1 range,
hence appear to be the main driver behind the increase in SFR density up to z~1
whereas local luminous galaxies are not, on the whole, representative of the
high redshift population.Comment: 5 pages, 3 figures, accepted for publication in MNRA
AEGIS: Infrared Spectral Energy Distributions of MIPS 70micron selected sources
We present 0.5 -160 micron Spectral Energy Distributions (SEDs) of galaxies,
detected at 70microns with the Multiband Imaging Photometer for Spitzer (MIPS),
using broadband imaging data from Spitzer and ground-based telescopes.
Spectroscopic redshifts, in the range 0.2<z<1.5, have been measured as part of
the Deep Extragalactic Evolutionary Probe2 (DEEP2) project. Based on the SEDs
we explore the nature and physical properties of the sources. Using the optical
spectra we derive Hbeta and [OII]-based Star Formation Rates (SFR) which are
10-100 times lower than SFR estimates based on IR and radio. The median offset
in SFR between optical and IR is reduced by a factor of ~3 when we apply a
typical extinction corrections. We investigate mid-to-far infrared correlations
for low redshift (>0.5) and high redshift (0.5<z<1.2) bins. Using this unique
``far-infrared'' selected sample we derive an empirical mid to far-infrared
relationship that can be used to estimate the infrared energy budget of
galaxies in the high-redshift universe. Our sample can be used as a template to
translate far-infrared luminosities into bolometric luminosities for high
redshift objects.Comment: 4 pages, 5 figures, accepted for publication in AEGIS ApJL Special
Issu
Environmental Protection without Loss of International Competitiveness
We develop a two-country Cournot oligopoly model with product differentiation across countries and production-generated pollution. The abatement of pollution by the firms in response to emission taxes is endogenous, and the number of firms can be fixed or there may be free entry and exit of firms in both countries. We propose particular unilateral and multilateral piecemeal policy reforms of emission taxes and production subsidies such that domestic industries will not suffer any loss of international competitiveness (defined in terms of either market share or profits), emission levels will be lower and welfare could be higher in both countries
Environmental Protection without Loss of International Competitiveness
We develop a two-country Cournot oligopoly model with product differentiation across countries and production-generated pollution. The abatement of pollution by the firms in response to emission taxes is endogenous, and the number of firms can be fixed or there may be free entry and exit of firms in both countries. We propose particular unilateral and multilateral piecemeal policy reforms of emission taxes and production subsidies such that domestic industries will not suffer any loss of international competitiveness (defined in terms of either market share or profits), emission levels will be lower and welfare could be higher in both countries
Local Guarantees in Graph Cuts and Clustering
Correlation Clustering is an elegant model that captures fundamental graph
cut problems such as Min Cut, Multiway Cut, and Multicut, extensively
studied in combinatorial optimization. Here, we are given a graph with edges
labeled or and the goal is to produce a clustering that agrees with the
labels as much as possible: edges within clusters and edges across
clusters. The classical approach towards Correlation Clustering (and other
graph cut problems) is to optimize a global objective. We depart from this and
study local objectives: minimizing the maximum number of disagreements for
edges incident on a single node, and the analogous max min agreements
objective. This naturally gives rise to a family of basic min-max graph cut
problems. A prototypical representative is Min Max Cut: find an cut
minimizing the largest number of cut edges incident on any node. We present the
following results: an -approximation for the problem of
minimizing the maximum total weight of disagreement edges incident on any node
(thus providing the first known approximation for the above family of min-max
graph cut problems), a remarkably simple -approximation for minimizing
local disagreements in complete graphs (improving upon the previous best known
approximation of ), and a -approximation for
maximizing the minimum total weight of agreement edges incident on any node,
hence improving upon the -approximation that follows from
the study of approximate pure Nash equilibria in cut and party affiliation
games
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