730 research outputs found

    The Wage Effects of Offshoring: Evidence from Danish Matched Worker-Firm Data

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    We estimate how offshoring and exporting affect wages by skill type. Our data match the population of Danish workers to the universe of private-sector Danish firms, whose trade flows are broken down by product and origin and destination countries. Our data reveal new stylized facts about offshoring activities at the firm level, and allow us to both condition our identification on within-job-spell changes and construct instruments for offshoring and exporting that are time varying and uncorrelated with the wage setting of the firm. We find that within job spells, (1) offshoring tends to increase the high-skilled wage and decrease the low-skilled wage; (2) exporting tends to increase the wages of all skill types; (3) the net wage effect of trade varies substantially across workers of the same skill type; and (4) conditional on skill, the wage effect of offshoring exhibits additional variation depending on task characteristics. We then track the outcomes for workers after a job spell and find that those displaced from offshoring firms suffer greater earnings losses than other displaced workers, and that low-skilled workers suffer greater and more persistent earnings losses than high-skilled workers.

    Happiness, environmental protection and market economy

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    The manufacturing sector is leaving the West for Asiaā€™s low wages and good working culture. Europe would be better off keeping these manufacturing activities, slowing down wage inflation and what is more, letting a young, cheaper workforce from the East settle down within their borders. This would aid in preserving the diverse economic structure which has been characteristic for Europe.Beside the economic growth there are two more concepts which have turned into the ā€œholy cowsā€ of economics during the last fifty years. One is the need to constantly improve labor productivity and the other is increasing competitiveness of nations. The high labor productivity of some countries, induces severe unemployment in the globalized world. In the other hand it is high time we understood that it is not competition, but cooperation that brings more happiness to humanity.Should we still opt for ā€œhappinessā€ and ā€œsanityā€, it is quite obvious that we all should, in economistsā€™ terms, define our individual welfare functions corresponding to our own set of values, staying free from the influence of media, advertisements and fashion. The cornerstone to all this is the intelligent citizen who prefers local goods and services

    Vertical Turbulent Cooling of the Mixed Layer in the Atlantic ITCZ and Trade Wind Regions

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    The causes of the seasonal cycle of vertical turbulent cooling at the base of the mixed layer are assessed using observations from moored buoys in the tropical Atlantic Intertropical Convergence Zone (ITCZ) (4Ā°N, 23Ā°W) and trade wind (15Ā°N, 38Ā°W) regions together with mixing parameterizations and a one-dimensional model. At 4Ā°N the parameterized turbulent cooling rates during 2017ā€“2018 and 2019 agree with indirect estimates from the climatological mooring heat budget residual: both show mean cooling of 25ā€“30 W m (Formula presented.) during Novemberā€“July, when winds are weakest and the mixed layer is thinnest, and 0ā€“10 W m (Formula presented.) during Augustā€“October. Mixing during Novemberā€“July is driven by variability on multiple time scales, including subdiurnal, near-inertial, and intraseasonal. Shear associated with tropical instability waves (TIWs) is found to generate mixing and monthly mean cooling of 15ā€“30 W m (Formula presented.) during Mayā€“July in 2017 and 2019. At 15Ā°N the seasonal cycle of turbulent cooling is out of phase compared to 4Ā°N, with largest cooling of up to 60 W m (Formula presented.) during boreal fall. However, the relationships between wind speed, mixed layer depth, and turbulent mixing are similar: weaker mean winds and a thinner mixed layer in the fall are associated with stronger mixing and turbulent cooling of SST. These results emphasize the importance of seasonal modulations of mixed layer depth at both locations and shear from TIWs at 4Ā°N

    CloudFlex: A Flexible Parametric Model for the Small-Scale Structure of the Circumgalactic Medium

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    We present CloudFlex, a new open-source tool for predicting the absorption-line signatures of cool gas in galaxy halos with complex small-scale structure. Motivated by analyses of cool material in hydrodynamical simulations of turbulent, multiphase media, we model individual cool gas structures as assemblies of cloudlets with a power-law distribution of cloudlet mass āˆmclāˆ’Ī±\propto m_{\rm cl}^{-\alpha} and relative velocities drawn from a turbulent velocity field. The user may specify Ī±\alpha, the lower limit of the cloudlet mass distribution (mcl,minm_{\rm cl,min}), and several other parameters that set the total mass, size, and velocity distribution of the complex. We then calculate the MgII 2796 absorption profiles induced by the cloudlets along pencil-beam lines of sight. We demonstrate that at fixed metallicity, the covering fraction of sightlines with equivalent widths W2796<0.3W_{2796} < 0.3 Ang increases significantly with decreasing mcl,minm_{\rm cl,min}, cool cloudlet number density (ncln_{\rm cl}), and cloudlet complex size. We then present a first application, using this framework to predict the projected W2796W_{2796} distribution around āˆ¼Lāˆ—{\sim}L^* galaxies. We show that the observed incidences of W2796>0.3W_{2796}>0.3 Ang sightlines within 10 kpc < RāŠ„R_{\perp} < 50 kpc are consistent with our model over much of parameter space. However, they are underpredicted by models with mcl,minā‰„100MāŠ™m_{\rm cl,min}\ge100M_{\odot} and nclā‰„0.03n_{\rm cl}\ge0.03 cmāˆ’3\rm cm^{-3}, in keeping with a picture in which the inner cool circumgalactic medium (CGM) is dominated by numerous low-mass cloudlets (mclā‰²100MāŠ™m_{\rm cl}\lesssim100M_{\odot}) with a volume filling factor ā‰²1%{\lesssim}1\%. When used to simultaneously model absorption-line datasets built from multi-sightline and/or spatially-extended background probes, CloudFlex will enable detailed constraints on the size and velocity distributions of structures comprising the photoionized CGM.Comment: 22 pages, 7 figures. Submitted to AAS Journals, with minor modifications. Comments welcome. (1) Co-first authors who made equal contributions to this wor

    A Two Micron All-Sky Survey View of the Sagittarius Dwarf Galaxy: II. Swope Telescope Spectroscopy of M Giant Stars in the Dynamically Cold Sagittarius Tidal Stream

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    We present moderate resolution (~6 km/s) spectroscopy of 284 M giant candidates selected from the Two Micron All Sky Survey photometry. Radial velocities (RVs) are presented for stars mainly in the south, with a number having positions consistent with association to the trailing tidal tail of the Sagittarius (Sgr) dwarf galaxy. The latter show a clear RV trend with orbital longitude, as expected from models of the orbit and destruction of Sgr. A minimum 8 kpc width of the trailing stream about the Sgr orbital midplane is implied by verified RV members. The coldness of this stream (dispersion ~10 km/s) provides upper limits on the combined contributions of stream heating by a lumpy Galactic halo and the intrinsic dispersion of released stars, which is a function of the Sgr core mass. The Sgr trailing arm is consistent with a Galactic halo containing one dominant, LMC-like lump, however some lumpier halos are not ruled out. An upper limit to the total M/L of the Sgr core is 21 in solar units. A second structure that roughly mimics expectations for wrapped, leading Sgr arm debris crosses the trailing arm in the Southern Hemisphere; however, this may also be an unrelated tidal feature. Among the <13 kpc M giants toward the South Galactic Pole are some with large RVs that identify them as halo stars, perhaps part of the Sgr leading arm near the Sun. The positions and RVs of Southern Hemisphere M giants are compared with those of southern globular clusters potentially stripped from the Sgr system and support for association of Pal 2 and Pal 12 with Sgr debris is found. Our discussion includes description of a masked-filtered cross-correlation methodology that achieves better than 1/20 of a resolution element RVs in moderate resolution spectra.Comment: 41 pages, 6 figures, Astronomical Journal, in press (submitted Nov. 24, 2003; tentatively scheduled for July 2004 issue

    Impact of Cosmic Rays on Thermal Instability in the Circumgalactic Medium

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    Large reservoirs of cold (~10ā“ K) gas exist out to and beyond the virial radius in the circumgalactic medium (CGM) of all types of galaxies. Photoionization modeling suggests that cold CGM gas has significantly lower densities than expected by theoretical predictions based on thermal pressure equilibrium with hot CGM gas. In this work, we investigate the impact of cosmic-ray physics on the formation of cold gas via thermal instability. We use idealized three-dimensional magnetohydrodynamic simulations to follow the evolution of thermally unstable gas in a gravitationally stratified medium. We find that cosmic-ray pressure lowers the density and increases the size of cold gas clouds formed through thermal instability. We develop a simple model for how the cold cloud sizes and the relative densities of cold and hot gas depend on cosmic-ray pressure. Cosmic-ray pressure can help counteract gravity to keep cold gas in the CGM for longer, thereby increasing the predicted cold mass fraction and decreasing the predicted cold gas inflow rates. Efficient cosmic-ray transport, by streaming or diffusion, redistributes cosmic-ray pressure from the cold gas to the background medium, resulting in cold gas properties that are in between those predicted by simulations with inefficient transport and simulations without cosmic rays. We show that cosmic rays can significantly reduce galactic accretion rates and resolve the tension between theoretical models and observational constraints on the properties of cold CGM gas

    Carbonyl Reduction by YmfI Completes the Modification of EF-P in \u3cem\u3eBacillus subtilis\u3c/em\u3e to Prevent Accumulation of an Inhibitory Modification State

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    Translation elongation factor P (EFā€P) in Bacillus subtilis is required for a form of surface migration called swarming motility. Furthermore, B. subtilis EFā€P is postā€translationally modified with a 5ā€aminopentanol group but the pathway necessary for the synthesis and ligation of the modification is unknown. Here we determine that the protein YmfI catalyzes the reduction of EFā€Pā€5 aminopentanone to EFā€Pā€5 aminopentanol. In the absence of YmfI, accumulation of 5ā€aminopentanonated EFā€P is inhibitory to swarming motility. Suppressor mutations that enhanced swarming in the absence of YmfI were found at two positions on EFā€P, including one that changed the conserved modification site (Lys 32) and abolished postā€translational modification. Thus, while modification of EFā€P is thought to be essential for EFā€P activity, here we show that in some cases it can be dispensable. YmfI is the first protein identified in the pathway leading to EFā€P modification in B. subtilis, and B. subtilis encodes the first EFā€P ortholog that retains function in the absence of modification

    Exploring Halo Substructure with Giant Stars III: First Results from the Grid Giant Star Survey and Discovery of a Possible Nearby Sagittarius Tidal Structure in Virgo

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    We describe first results of a spectroscopic probe of selected fields from the Grid Giant Star Survey. Multifiber spectroscopy of several hundred stars in a strip of eleven fields along delta approximately -17^{circ}, in the range 12 <~ alpha <~ 17 hours, reveals a group of 8 giants that have kinematical characteristics differing from the main field population, but that as a group maintain coherent, smoothly varying distances and radial velocities with position across the fields. Moreover, these stars have roughly the same abundance, according to their MgH+Mgb absorption line strengths. Photometric parallaxes place these stars in a semi-loop structure, arcing in a contiguous distribution between 5.7 and 7.9 kpc from the Galactic center. The spatial, kinematical, and abundance coherence of these stars suggests that they are part of a diffuse stream of tidal debris, and one roughly consistent with a wrapped, leading tidal arm of the Sagittarius dwarf spheroidal galaxy.Comment: 8 pages including 4 figures. Accepted for publication in ApJ
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