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 $s-t$ 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 $s-t$ Cut: find an $s-t$ cut minimizing the largest number of cut edges incident on any node. We present the following results: $(1)$ an $O(\sqrt{n})$-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), $(2)$ a remarkably simple $7$-approximation for minimizing local disagreements in complete graphs (improving upon the previous best known approximation of $48$), and $(3)$ a $1/(2+\varepsilon)$-approximation for maximizing the minimum total weight of agreement edges incident on any node, hence improving upon the $1/(4+\varepsilon)$-approximation that follows from the study of approximate pure Nash equilibria in cut and party affiliation games