10,328 research outputs found
Oil Price Indexing Of Natural Gas Prices: An Economic Analysis
Oil price indexing is a peculiar feature of the natural gas markets in Germany and other European countries. It is closely linked to the existence of local monopolies (at least de facto) and of the so called "take-or-pay" (TOP) contracts. After discussing the relation between these features and the motivations for oil price indexing, we formally analyze this strategy in a differentiated good oligoply with a monopolistic supplier of natural gas and competing oil distributors. Starting with a symmetric setting, we first point out how oil price indexing works as a collusive device. In a second step we account for the likely asymmetries between oil and gas distributors. We show that the result obtained under symmetry is not robust and we discuss how the impact of oil price indexing on prices, profits and welfare depends on the form and extent of the asymmetries. -- Die Ölpreisbindung des Erdgaspreises ist ein hervorstechendes Merkmal des Gasmarktes in Deutschland und anderen europäischen Ländern. Diese Besonderheit ist eng verknüpft mit der Existenz lokaler Monopole (trotz Liberalisierung bestehen diese bislang zumindest in Deutschland de facto weiterhin) und sogenannter "take-or-pay" Verträge (TOP contracts), d. h. fixer Abnahmeverpflichtungen zu einem an die Entwicklung des Ölpreises gekoppelten Abnahmepreises. Nach einer Diskussion der Beziehung zwischen diesen drei Besonderheiten des Erdgasmarktes und der möglichen Gründe für die Ölpreisbindung analysieren wir diese Strategie in einem Oligopolmodell mit differenzierten Produkten mit einem monopolistischen Erdgasanbieter und einem oder mehreren konkurrierenden Ölhändlern. Zunächst zeigen wir im Rahmen einer symmetrischen Spezifikation auf, wie die Ölpreisbindung die Kollusion zwischen Erdgas? und Ölanbietern ermöglicht. Anschließend berücksichtigen wir mögliche Asymmetrien zwischen den beiden Energieformen. Dabei zeigt sich, dass das Ergebnis bei Symmetrie nicht robust ist und wir diskutieren im Detail wie die Auswirkung der Ölpreisbindung auf Preise, Gewinne und Wohlfahrt von der Art und vom Ausmaß der Asymmetrien abhängt.Natural gas market,Oligopoly,oil price indexing,Take-or-pay contracts
A sequential semidefinite programming method and an application in passive reduced-order modeling
We consider the solution of nonlinear programs with nonlinear
semidefiniteness constraints. The need for an efficient exploitation of the
cone of positive semidefinite matrices makes the solution of such nonlinear
semidefinite programs more complicated than the solution of standard nonlinear
programs. In particular, a suitable symmetrization procedure needs to be chosen
for the linearization of the complementarity condition. The choice of the
symmetrization procedure can be shifted in a very natural way to certain linear
semidefinite subproblems, and can thus be reduced to a well-studied problem.
The resulting sequential semidefinite programming (SSP) method is a
generalization of the well-known SQP method for standard nonlinear programs. We
present a sensitivity result for nonlinear semidefinite programs, and then
based on this result, we give a self-contained proof of local quadratic
convergence of the SSP method. We also describe a class of nonlinear
semidefinite programs that arise in passive reduced-order modeling, and we
report results of some numerical experiments with the SSP method applied to
problems in that class
Polarized semi-inclusive electroweak structure functions at next-to-leading-order
We present a next-to-leading order (NLO) computation of the full set of
polarized and unpolarized electroweak semi-inclusive DIS (SIDIS) structure
functions, whose knowledge is crucial for a precise extraction of polarized
parton distributions. We focus on the phenomenology of the polarized structure
functions for the kinematical conditions that could be reached in an
Electron-Ion-Collider.
We show that the NLO corrections are sizeable, particularly in the small-
range. We test the sensitivity of these structure functions on certain quark
distributions and compare it to the situation of inclusive DIS and
electromagnetic SIDIS.Comment: 17 pages, 5 figure
Voltage Stabilization in Microgrids via Quadratic Droop Control
We consider the problem of voltage stability and reactive power balancing in
islanded small-scale electrical networks outfitted with DC/AC inverters
("microgrids"). A droop-like voltage feedback controller is proposed which is
quadratic in the local voltage magnitude, allowing for the application of
circuit-theoretic analysis techniques to the closed-loop system. The operating
points of the closed-loop microgrid are in exact correspondence with the
solutions of a reduced power flow equation, and we provide explicit solutions
and small-signal stability analyses under several static and dynamic load
models. Controller optimality is characterized as follows: we show a one-to-one
correspondence between the high-voltage equilibrium of the microgrid under
quadratic droop control, and the solution of an optimization problem which
minimizes a trade-off between reactive power dissipation and voltage
deviations. Power sharing performance of the controller is characterized as a
function of the controller gains, network topology, and parameters. Perhaps
surprisingly, proportional sharing of the total load between inverters is
achieved in the low-gain limit, independent of the circuit topology or
reactances. All results hold for arbitrary grid topologies, with arbitrary
numbers of inverters and loads. Numerical results confirm the robustness of the
controller to unmodeled dynamics.Comment: 14 pages, 8 figure
Regional income distribution and human capital formation: A model of intergenerational education transfer in a global context
The demographic problems in developed countries are getting more and more important. Very low fertility rates especially among skilled individuals will soon become relevant for a country's economy. Also of importance is education of children. Since there is an increasing demand for skilled workers, the positive correlation between social background and education worsens the situation. Therefore family planning as well as fertility providing and educational measures are of major importance for regional decision makers. We define in our model the optimal number of children considering the income and education of their parents by using a Cobb-Douglas utility function which implies that children and consumption are complementary goods. Children are considered to be a differentiated good with respect to their education. Therefore, we distinguish between high educated and low educated children. After deciding the optimal number of children, the education level of children has to be determined. We assume that only one parent is responsible for the education. Further we presume a negative correlation between the opportunity costs of educating a child and their parent's qualification. Since we consider the parents income and education, many cases result. Regional policy makers have the possibility to change individual decisions regarding offspring by creating monetary incentives. As wages and therefore family income are exogenous, the regional governments have only two policy measures left: either child allowance and/or scholarships. Considering the population's preferences, regions may optimize the number and structure of children. --population policy,education,qualification,factor proportions,globalization
Global analysis of helicity PDFs: past - present - future
We discuss the current status of the DSSV global analysis of
helicity-dependent parton densities. A comparison with recent semi-inclusive
DIS data from COMPASS is presented, and constraints on the polarized
strangeness density are examined in some detail.Comment: Talk presented at the XIX Int. Workshop on Deep-Inelastic Scattering
and Related Subjects (DIS 2011); 4 pages; 2 figure
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