6,327 research outputs found
Why do People Stay? Insider Advantages and Immobility
The low mobility of people in Europe is considered a problem for adjustment to asymmetric shocks and regional convergence in the European Monetary Union. We suggest a complement to the traditional migration theories, the insider advantages approach to explain why most Europeans prefer to stay. Staying immobile they have accumulated work- and leisure-oriented insider advantages that are location-specific and would be lost in the case of emigration. Therefore, the longer people have stayed - and the more insider advantages they have accumulated -, the less likely they are to move. Using a new micro dataset covering all people resident in Sweden in 1994 and their mobility experience since 1985, we find a strong positive duration dependence of the probability to stay. Traditional micro-economic characteristics prove helpful in explaining immobility, while regional macro-economic differences have surprisingly little impact on individual mobility decisions. A large proportion of the moves between Swedish labour markets seem to be related to specific life-course events rather than to pure labour market issues. Wieso ist die Mobilität der Arbeitskräfte innerhalb der Europäischen Union - aller Freizügigkeit zum Trotz - so gering? Traditionelle Theorieansätze vermögen die schwach ausgeprägte Wanderungsintensität der EU-Angehörigen nur begrenzt zu er - klären. Denn eigentlich sollten die teilweise beträchtlichen Einkommens - und Beschäftigungsunterschiede zu weit mehr Migration innerhalb der EU führen. In diesem Diskussionspapier entwickeln wir eine Idee, die sehr wohl zu erklären vermag, weshalb für die meisten Menschen "stehen" die bessere Alternative als "gehen" ist. Der Insider-Ansatz macht deutlich, weshalb für die individuelle Entscheidung eine grenz- und kulturraumüberschreitende Wanderung die Ausnahme und nicht die Regel ist. Die empirische Überprüfung mit Hilfe eines neuen originären Mikro-Datensets, das die gesamte schwedische Wohnbevölkerung enthält, bestätigt die These, dass die Verweil- dauer einen direkten positiven Einfluss auf die Verharrenswahrscheinlichkeit ausübt. Wer lange an einem Ort lebt, wird immer wahrscheinlicher an diesem Ort bleiben!Labor and Human Capital, F22, J60, R23,
Immobility in Sweden : Are those born in the Baltic countries less mobile than those born in Sweden or Finland
Traditional migration theory analyzes and explains why and when people migrate. However, most people do not move at all. We therefore discuss the explanation of immobility and suggest a new approach: the insider-advantage hypothesis. A new dataset allows us to investigate empirically (im-)mobility patterns between Swedish labor market regions. From an aggregate point of view, there seem to be significant differences in mobility patterns with respect to place of birth. People bom in Sweden are on average more immobile than those bom abroad. This is true also for those bom in Finland. The mobility of Persons bom in the Baltic countries, however, was only half as high as for those bom in Sweden. Are Balts thus especially immobile in Sweden? Our analysis ot the data suggests that distinct socio-demographic Profiles rather than any origin-specific behavioral particularities explain the different mobility patterns. People living in Sweden who were bom in the Baltic countries are on average older than Swedish natives. They are resident in the country for longer than most other groups of foreigners and cluster in the main metropolitan areas
Correlated projection operator approach to non-Markovian dynamics in spin baths
The dynamics of an open quantum system is usually studied by performing a
weak-coupling and weak-correlation expansion in the system-bath interaction.
For systems exhibiting strong couplings and highly non-Markovian behavior this
approach is not justified. We apply a recently proposed correlated projection
superoperator technique to the model of a central spin coupled to a spin bath
via full Heisenberg interaction. Analytical solutions to both the
Nakajima-Zwanzig and the time-convolutionless master equation are determined
and compared with the results of the exact solution. The correlated projection
operator technique significantly improves the standard methods and can be
applied to many physical problems such as the hyperfine interaction in a
quantum dot
Two Jovian-Mass Planets in Earthlike Orbits
We report the discovery of two new planets: a 1.94 M_Jup planet in a 1.8-year
orbit of HD 5319, and a 2.51 M_Jup planet in a 1.1-year orbit of HD 75898. The
measured eccentricities are 0.12 for HD 5319 b and 0.10 for HD 75898 b, and
Markov Chain Monte Carlo simulations based on derived orbital parameters
indicate that the radial velocities of both stars are consistent with circular
planet orbits. With low eccentricity and 1 < a < 2 AU, our new planets have
orbits similar to terrestrial planets in the solar system. The radial velocity
residuals of both stars have significant trends, likely arising from substellar
or low-mass stellar companions.Comment: 32 pages, including 11 figures and 5 tables. Accepted by Ap
CHIRON - A Fiber Fed Spectrometer for Precise Radial Velocities
The CHIRON optical high-resolution echelle spectrometer was commissioned at
the 1.5m telescope at CTIO in 2011. The instrument was designed for high
throughput and stability, with the goal of monitoring radial velocities of
bright stars with high precision and high cadence for the discovery of low-mass
exoplanets. Spectral resolution of R=79,000 is attained when using a slicer
with a total (including telescope and detector) efficiency of 6% or higher,
while a resolution of R=136,000 is available for bright stars. A fixed spectral
range of 415 to 880 nm is covered. The echelle grating is housed in a vacuum
enclosure and the instrument temperature is stabilized to +-0.2deg. Stable
illumination is provided by an octagonal multimode fiber with excellent
light-scrambling properties. An iodine cell is used for wavelength calibration.
We describe the main optics, fiber feed, detector, exposure-meter, and other
aspects of the instrument, as well as the observing procedure and data
reduction.Comment: 15 pages, 10 figures. Accepted by PAS
Dissipationless Spin Current between Two Coupled Ferromagnets
We demonstrate the general principle which states that a dissipationless spin
current flows between two coupled ferromagnets if their magnetic orders are
misaligned. This principle applies regardless the two ferromagnets are metallic
or insulating, and also generally applies to bulk magnetic insulators. On a
phenomenological level, this principle is analogous to Josephson effect, and
yields a dissipationless spin current that is independent from scattering. The
microscopic mechanisms for the dissipationless spin current depend on the
systems, which are elaborated in details. A uniform, static magnetic field is
further proposed to be an efficient handle to create the misaligned
configuration and stabilize the dissipationless spin current.Comment: 10 pages, 5 figure
Consequences Of Fully Dressing Quark-Gluon Vertex Function With Two-Point Gluon Lines
We extend recent studies of the effects of quark-gluon vertex dressing upon
the solutions of the Dyson-Schwinger equation for the quark propagator. A
momentum delta function is used to represent the dominant infrared strength of
the effective gluon propagator so that the resulting integral equations become
algebraic. The quark-gluon vertex is constructed from the complete set of
diagrams involving only 2-point gluon lines. The additional diagrams, including
those with crossed gluon lines, are shown to make an important contribution to
the DSE solutions for the quark propagator, because of their large color
factors and the rapid growth in their number
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