2,899 research outputs found
The Contribution of Local Public Infrastructure to Private Productivity and Its Political-Economy: Evidence from a Panel of Large German Cities
TThis paper proposes a simultaneous-equation approach to the estimation of the contribution of infrastructure accumulation to private production. A political economy model for the allocation of public infrastructure investment grants is formulated. Our empirical findings, using a panel of large German cities for the years 1980, 1986, and 1988, suggest that cities ruled by a council sharing the State ('Bundesland') government's current political affiliation were particularly successful in attracting infrastructure investment grants. With regard to the contribution of infrastructure accumulation to growth, we find that public capital is a significant factor in private production. Moreover, at least for the sample studied, we find that simultaneity between output and public capital is weak; thus, feedback effects from output to infrastructure are negligible. ZUSAMMENFASSUNG - (Der Beitrag lokaler öffentlicher Infrastruktur zur privaten Produktivität und seine politische Ökonomie: Empirische Evidenz von einem Paneldatensatz großer deutscher Städte) Dieses Papier verwendet ein simultanes Gleichungssystem zur Schätzung des Beitrags von Infrastrukturinvestitionen zu regionalem Wachstum. Ein polit-ökonomisches Modell der Allokation von Finanzzuweisungen für öffentliche Investitionen in Infrastruktur wird formuliert. Unsere empirischen Ergebnisse basierend auf einem Paneldatensatz für große deutsche Städte in den Jahren 1980, 1986 und 1988 deuten darauf hin, dass Städte, deren Mehrheit im Stadtrat die selbe politische "Couleur" wie die Landesregierung hatte, erfolgreicher bei der Zuteilung von Finanzzuweisungen waren. Im Hinblick auf den Beitrag der Infrastrukturakkumulation auf das Wachstum finden wir, dass öffentliches Kapital ein wichtiger Faktor für die private Produktion ist. Weiterhin, zumindest für den untersuchten Zeitraum, finden wir, dass die Simultanität zwischen Output und öffentlichem Kapital gering ist; daher sind Feedback-Effekte von Output zur Infrastruktur vernachlässigbar.Local Infrastructure, Intergovernmental Grants, Productivity
Political Economy of Infrastructure Investment Allocation: Evidence from a Panel of Large German Cities
This paper proposes a simultaneous-equation approach to the estimation of the contribution of infrastructure accumulation to private production. A political-economy model for the allocation of public infrastructure investment grants is formulated. Our empirical findings, using a panel of large German cities for the years 1980, 1986, and 1988, suggest that cities ruled by a council sharing the State (‘Bundesland’) government's current political affiliation were particularly successful in attracting infrastructure investment grants. With regard to the contribution of infrastructure accumulation to growth, we find that public capital is a significant factor for private production. Moreover, at least for the sample studied, we find that simultaneity between output and public capital is weak; thus, feedback effects from output to infrastructure are negligible. ZUSAMMENFASSUNG - (Politische Ökonomie der Allokation von Infrastrukturinvestitionen: Empirische Evidenz von einem Paneldatensatz großer deutscher Städte) Dieses Papier verwendet ein simultanes Gleichungssystem zur Schätzung des Beitrags von Infrastrukturinvestitionen zu regionalem Wachstum. Ein polit-ökonomisches Modell der Allokation von Finanzzuweisungen für öffentliche Investitionen in Infrastruktur wird formuliert. Unsere empirischen Ergebnisse basierend auf einem Paneldatensatz für große deutsche Städte in den Jahren 1980, 1986 und 1988 deuten darauf hin, dass Städte, deren Mehrheit im Stadtrat die selbe politische "Couleur" wie die Landesregierung hatte, erfolgreicher bei der Zuteilung von Finanzzuweisungen waren. Im Hinblick auf den Beitrag der Infrastrukturakkumulation auf das Wachstum finden wir, dass öffentliches Kapital ein wichtiger Faktor für die private Produktion ist. Weiterhin, zumindest für den untersuchten Zeitraum, finden wir, dass die Simultanität zwischen Output und öffentlichem Kapital gering ist; daher sind Feedback-Effekte von Output zur Infrastruktur vernachlässigbar.
Interacting Fermionic Atoms in Optical Lattices Diffuse Symmetrically Upwards and Downwards in a Gravitational Potential
We consider a cloud of fermionic atoms in an optical lattice described by a
Hubbard model with an additional linear potential. While homogeneous
interacting systems mainly show damped Bloch oscillations and heating, a finite
cloud behaves differently: It expands symmetrically such that gains of
potential energy at the top are compensated by losses at the bottom.
Interactions stabilize the necessary heat currents by inducing gradients of the
inverse temperature 1/T, with T<0 at the bottom of the cloud. An analytic
solution of hydrodynamic equations shows that the width of the cloud increases
with t^(1/3) for long times consistent with results from our Boltzmann
simulations.Comment: 4 pages, 4 figures plus supplementary material (2 pages, 1 figure),
published versio
Equilibration rates and negative absolute temperatures for ultracold atoms in optical lattices
As highly tunable interacting systems, cold atoms in optical lattices are
ideal to realize and observe negative absolute temperatures, T < 0. We show
theoretically that by reversing the confining potential, stable superfluid
condensates at finite momentum and T < 0 can be created with low entropy
production for attractive bosons. They may serve as `smoking gun' signatures of
equilibrated T < 0. For fermions, we analyze the time scales needed to
equilibrate to T < 0. For moderate interactions, the equilibration time is
proportional to the square of the radius of the cloud and grows with increasing
interaction strengths as atoms and energy are transported by diffusive
processes.Comment: published version, minor change
Long-lived anomalous thermal diffusion induced by elastic cell membranes on nearby particles
The physical approach of a small particle (virus, medical drug) to the cell
membrane represents the crucial first step before active internalization and is
governed by thermal diffusion. Using a fully analytical theory we show that the
stretching and bending of the elastic membrane by the approaching particle
induces a memory in the system which leads to anomalous diffusion, even though
the particle is immersed in a purely Newtonian liquid. For typical cell
membranes the transient subdiffusive regime extends beyond 10 ms and can
enhance residence times and possibly binding rates up to 50\%. Our analytical
predictions are validated by numerical simulations.Comment: 13 pages and 5 figures. The Supporting Information is included.
Manuscript accepted for publication in Phys. Rev.
Particle mobility between two planar elastic membranes: Brownian motion and membrane deformation
We study the motion of a solid particle immersed in a Newtonian fluid and
confined between two parallel elastic membranes possessing shear and bending
rigidity. The hydrodynamic mobility depends on the frequency of the particle
motion due to the elastic energy stored in the membrane. Unlike the
single-membrane case, a coupling between shearing and bending exists. The
commonly used approximation of superposing two single-membrane contributions is
found to give reasonable results only for motions in the parallel, but not in
the perpendicular direction. We also compute analytically the membrane
deformation resulting from the motion of the particle, showing that the
presence of the second membrane reduces deformation. Using the
fluctuation-dissipation theorem we compute the Brownian motion of the particle,
finding a long-lasting subdiffusive regime at intermediate time scales. We
finally assess the accuracy of the employed point-particle approximation via
boundary-integral simulations for a truly extended particle. They are found to
be in excellent agreement with the analytical predictions.Comment: 14 pages, 8 figures and 96 references. Revised version resubmitted to
Phys. Fluid
Numerical-experimental observation of shape bistability of red blood cells flowing in a microchannel
Red blood cells flowing through capillaries assume a wide variety of
different shapes owing to their high deformability. Predicting the realized
shapes is a complex field as they are determined by the intricate interplay
between the flow conditions and the membrane mechanics. In this work we
construct the shape phase diagram of a single red blood cell with a
physiological viscosity ratio flowing in a microchannel. We use both
experimental in-vitro measurements as well as 3D numerical simulations to
complement the respective other one. Numerically, we have easy control over the
initial starting configuration and natural access to the full 3D shape. With
this information we obtain the phase diagram as a function of initial position,
starting shape and cell velocity. Experimentally, we measure the occurrence
frequency of the different shapes as a function of the cell velocity to
construct the experimental diagram which is in good agreement with the
numerical observations. Two different major shapes are found, namely croissants
and slippers. Notably, both shapes show coexistence at low (<1 mm/s) and high
velocities (>3 mm/s) while in-between only croissants are stable. This
pronounced bistability indicates that RBC shapes are not only determined by
system parameters such as flow velocity or channel size, but also strongly
depend on the initial conditions.Comment: 13 pages, 9 figures (main text). 13 pages, 31 figures (SI
The contribution of local public infrastructure to private productivity and its political-economy: evidence from a panel of large German cities
"This paper proposes a simultaneous-equation approach to the estimation of the contribution of infrastructure accumulation to private production. A political economy model for the allocation of public infrastructure investment grants is formulated. The empirical findings, using a panel of large German cities for the years 1980, 1986, and 1988, suggest that cities ruled by a council sharing the State ('Bundesland') government's current political affiliation were particularly successful in attracting infrastructure investment grants. With regard to the contribution of infrastructure accumulation to growth, the authors find that public capital is a significant factor in private production. Moreover, at least for the sample studied, they find that simultaneity between output and public capital is weak; thus, feedback effects from output to infrastructure are negligible." (author's abstract)"Dieses Papier verwendet ein simultanes Gleichungssystem zur Schätzung des Beitrags von Infrastrukturinvestitionen zu regionalem Wachstum. Ein polit-ökonomisches Modell der Allokation von Finanzzuweisungen für öffentliche Investitionen in Infrastruktur wird formuliert. Die empirischen Ergebnisse basierend auf einem Paneldatensatz für große deutsche Städte in den Jahren 1980, 1986 und 1988 deuten darauf hin, dass Städte, deren Mehrheit im Stadtrat die selbe politische 'Couleur' wie die Landesregierung hatte, erfolgreicher bei der Zuteilung von Finanzzuweisungen waren. Im Hinblick auf den Beitrag der Infrastrukturakkumulation auf das Wachstum finden die Autoren, dass öffentliches Kapital ein wichtiger Faktor für die private Produktion ist. Weiterhin, zumindest für den untersuchten Zeitraum, finden sie, dass die Simultanität zwischen Output und öffentlichem Kapital gering ist; daher sind Feedback-Effekte von Output zur Infrastruktur vernachlässigbar." (Autorenreferat
Political economy of infrastructure investment allocation: evidence from a panel of large German cities
"This paper proposes a simultaneous-equation approach to the estimation of the contribution of infra-structure accumulation to private production. A political-economy model for the allocation of public infrastructure investment grants is formulated. The empirical findings, using a panel of large German cities for the years 1980, 1986, and 1988, suggest that cities ruled by a council sharing the State ('Bundesland') government's current political affiliation were particularly successful in attracting infrastructure investment grants. With regard to the contribution of infrastructure accumulation to growth, the authors find that public capital is a significant factor for private production. Moreover, at least for the sample studied, the authors find that simultaneity between output and public capital is weak; thus, feedback effects from output to infrastructure are negligible." (author's abstract)"Dieses Papier verwendet ein simultanes Gleichungssystem zur Schätzung des Beitrags von Infrastrukturinvestitionen zu regionalem Wachstum. Ein polit-ökonomisches Modell der Allokation von Finanzzuweisungen für öffentliche Investitionen in Infrastruktur wird formuliert. Die empirischen Ergebnisse basierend auf einem Paneldatensatz für große deutsche Städte in den Jahren 1980, 1986 und 1988 deuten darauf hin, dass Städte, deren Mehrheit im Stadtrat die selbe politische 'Couleur' wie die Landesregierung hatte, erfolgreicher bei der Zuteilung von Finanzzuweisungen waren. Im Hinblick auf den Beitrag der Infrastrukturakkumulation auf das Wachstum finden die Autoren, dass öffentliches Kapital ein wichtiger Faktor für die private Produktion ist. Weiterhin, zumindest für den untersuchten Zeitraum, finden die Autoren, dass die Simultanität zwischen Output und öffentlichem Kapital gering ist; daher sind Feedback-Effekte von Output zur Infrastruktur vernachlässigbar." (Autorenreferat
Funding and operation of stadiums and arenas beside high-class leagues
Financing and operating stadiums and arenas beside the respective national high-class leagues are demanding tasks for those involved, mostly clubs or local governments. In the majority of cases, the affected clubs and teams heavily rely on ticket and catering revenues or sponsorships since the marketing of TV rights is of negligible importance. Nevertheless, the respective stadiums and arenas are often old and lack modern comfort on account of budget constraints impeding capital spending by clubs or governments. Starting from these observations and considering the features of the relevant sports facilities, we examine which funding and operating models could improve the endowment with stadiums and arenas in an efficiency-maximizing way and derive helpful recommandations for clubs, policy makers and private investors. For this purpose, we also establish four criteria to assess the efficiency of any stadium or arena construction and operation models, namely funding efficiency, cost efficiency, management efficiency and allocation efficiency. (Note: This paper is in German.)sports facilities, public funding, public-private-partnerships
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