The role of worker flows in the dynamics and distribution of UK unemployment

Unemployment varies substantially over time and across subgroups of the labour market. Worker flows among labour market states act as key determinants of this variation. We examine how the structure of unemployment across groups and its cyclical movements across time are shaped by changes in labour market flows. Using novel estimates of flow transition rates for the UK over the last 35 years, we decompose unemployment variation into parts accounted for by changes in rates of job loss, job finding and flows via non-participation. Close to two-thirds of the volatility of unemployment in the UK over this period can be traced to rises in rates of job loss that accompany recessions. The share of this inflow contribution has been broadly the same in each of the past three recessions. Decreased job-finding rates account for around one-quarter of unemployment cyclicality and the remaining variation can be attributed to flows via non-participation. Digging deeper into the structure of unemployment by gender, age and education, the flow-approach is shown to provide a richer understanding of the unemployment experiences across population subgroups. Key words: labour market ; unemployment ; worker flows JEL classification: E24 ; J6

Population growth, immigration, and labor market dynamics

This article provides a first synthesis of population flows and labor market dynamics across immigrant and native-born populations. We devise a novel dynamic accounting methodology that integrates population flows from two sources-changes in birth cohort size and immigrant flows-with labor market dynamics. We illustrate the method using data for the United Kingdom, where population flows have been large and cyclical, driven first by the maturation of baby boom cohorts in the 1980s and later by immigration in the 2000s. New measures of labor market flows by migrant status uncover the flow origins of disparities in the levels and cyclicality of immigrant and native labor market outcomes and their more recent convergence. An application of our accounting framework reveals that population flows have played a nontrivial role in the volatility of labor markets among the UK-born and, especially, immigrants

NNLO Corrections to the Polarized Drell-Yan Coefficient Function

We present the full next-to-next-to-leading order (NNLO) corrections to the coefficient function for the polarized cross section $d \Delta\sigma/d Q$ of the Drell-Yan process. We study the effect of these corrections on the process $p+p\to l^+l^-+`X'$ at an C.M. energy $\sqrt{S}=200 GeV$. All QCD partonic subprocesses have been included provided the lepton pair is created by a virtual photon, which is a valid approximation for a lepton pair invariant mass $Q<50 GeV$. For this reaction the dominant subprocess is given by $q+\bar q\to \gamma^*+`X'$ and its higher order corrections so that it provides us with an excellent tool to measure the polarized sea-quark densities.Comment: 5 pages, 5 figures, 7th DESY Workshop on Elementary Particle Theory, Loops and Legs in Quantum Field Theory, Zinnowitz, Germany, April 25-30, 200

Population Growth, Immigration and Labor Market Dynamics

This article provides a first synthesis of population flows and labor market dynamics across immigrant and native-born populations. We devise a novel dynamic accounting methodology that integrates population flows from two sources-changes in birth cohort size and immigrant flows-with labor market dynamics. We illustrate the method using data for the United Kingdom, where population flows have been large and cyclical, driven first by the maturation of baby boom cohorts in the 1980s and later by immigration in the 2000s. New measures of labor market flows by migrant status uncover the flow origins of disparities in the levels and cyclicality of immigrant and native labor market outcomes and their more recent convergence. An application of our accounting framework reveals that population flows have played a nontrivial role in the volatility of labor markets among the UK-born and, especially, immigrants

Trying again to fail-first

For constraint satisfaction problems (CSPs), Haralick and Elliott [1] introduced the Fail-First Principle and defined in it terms of minimizing branch depth. By devising a range of variable ordering heuristics, each in turn trying harder to fail first, Smith and Grant [2] showed that adherence to this strategy does not guarantee reduction in search effort. The present work builds on Smith and Grant. It benefits from the development of a new framework for characterizing heuristic performance that defines two policies, one concerned with enhancing the likelihood of correctly extending a partial solution, the other with minimizing the effort to prove insolubility. The Fail-First Principle can be restated as calling for adherence to the second, fail-first policy, while discounting the other, promise policy. Our work corrects some deficiencies in the work of Smith and Grant, and goes on to confirm their finding that the Fail-First Principle, as originally defined, is insufficient. We then show that adherence to the fail-first policy must be measured in terms of size of insoluble subtrees, not branch depth. We also show that for soluble problems, both policies must be considered in evaluating heuristic performance. Hence, even in its proper form the Fail-First Principle is insufficient. We also show that the “FF” series of heuristics devised by Smith and Grant is a powerful tool for evaluating heuristic performance, including the subtle relations between heuristic features and adherence to a policy

Bottom quark electroproduction in variable flavor number schemes

Two variable flavor number schemes are used to describe bottom quark production in deep inelastic electron-proton scattering. In these schemes the coefficient functions are derived from mass factorization of the heavy quark coefficient functions presented in a fixed flavor number scheme. Also one has to construct a parton density set with five light flavors (u,d,s,c,b) out of a set which only contains four light flavors (u,d,s,c). In order $\alpha_s^2$ the two sets are discontinuous at $\mu=m_b$ which follows from mass factorization of the heavy quark coefficient functions when it is carried out in the ${\bar {\rm MS}}$-scheme. Both variable flavor number schemes give almost identical predictions for the bottom structure functions $F_{2,b}$ and $F_{L,b}$. Also they both agree well with the corresponding results based on fixed order four-flavor perturbation theory over a wide range in $x$ and $Q^2$.Comment: Latex with seventeen PostScript figure

An extremely low gas-to-dust ratio in the dust-lane lenticular galaxy NGC 5485

Date of Acceptance: 21/07/2014Peer reviewe

High Pressure Study on MgB2

The hydrostatic pressure effect on the newly discovered superconductor MgB2 has been determined. The transition temperature Tc was found to decrease linearly at a large rate of -1.6 K/GPa, in good quantitative agreement with the ensuing calculated value of -1.4 K/GPa within the BCS framework by Loa and Syassen, using the full-potential linearlized augmented plane-wave method. The relative pressure coefficient, dlnTc/dp, for MgB2 also falls between the known values for conventional sp- and d-superconductors. The observation, therefore, suggests that electron-phonon interaction plays a significant role in the superconductivity of the compound.Comment: 8 pages, 3 figures; submitted to Physical Review B (February 14, 2001; revised March 21, 2001); minor modifications, including a discussion of the preprint by Vogt et a

Wavelength dependent ac-Stark shift of the 1S0 - 3P1 transition at 657 nm in Ca

We have measured the ac-Stark shift of the 4s2 1S0 - 4s4p 3P1 line in 40Ca for perturbing laser wavelengths between 780 nm and 1064 nm with a time domain Ramsey-Borde atom interferometer. We found a zero crossing of the shift for the mS = 0 - mP = 0 transition and \sigma polarized perturbation at 800.8(22) nm. The data was analyzed by a model deriving the energy shift from known transition wavelengths and strengths. To fit our data, we adjusted the Einstein A coefficients of the 4s3d 3D - 4s4p 3P and 4s5s 3S - 4s4p 3P fine structure multiplets. With these we can predict vanishing ac-Stark shifts for the 1S0 m = 0 - 3P1 m = 1 transition and \sigma- light at 983(12) nm and at 735.5(20) nm for the transition to the 3P0 level.Comment: 8 pages, 5 figures, 2 table

Top Quark Production Cross Section

The production rate for top quarks at the Fermilab Tevatron is presented using the exact order $\alpha_s^3$ corrected cross section and the resummation of the leading soft gluon corrections in all orders of perturbation theory.Comment: preprint FERMILAB-Pub-93/270-T, ITP-SB-93-55, THU-93/23, Latex 9 pages, 8 postscript figures, uuencoded and appended at end of fil