Trade disclosure and price dispersion

This paper determines the effects of post-trade opaqueness on market performance. We find that the degree of market transparency has important effects on market equilibria. In particular, we show that dealers operating in a transparent structure set regret-free prices at each period making zero expected profits in each of the two trading rounds, whereas in the opaque market dealers invest in acquiring information at the beginning of the trading day. Moreover, we obtain that if there is no trading activity in the first period, then market makers only change their quotes in the opaque market. Additionally, we show that trade disclosure increases the informational efficiency of transaction prices and reduces volatility. Finally, concerning welfare of market participants, we obtain ambiguous results. Keywords: Market microstructure, Post-trade transparency, Price experimentation, Price dispersion.

Information Dispersion and Equilibrium Multiplicity

This paper studies the implications of correlation of private signals about the liquidation value of a risky asset in a variation of a standard noisy rational expectations model in which traders receive endowment shocks which are private information and have a common component. We …nd that a necessary condition to generate multiple linear partially revealing rational expectations equilibria is the existence of several sources of information dispersion. In this context equilibrium multiplicity tends to occur when information is more dispersed. A necessary condition to have strategic complementarity in information acquisition is to have mul- tiple equilibria. When the equilibrium is unique there is strategic substi- tutability in information acquisition, corroborating the result obtained in Grossman and Stiglitz (1980). JEL Classi…cation: D82, D83, G14 Keywords: Multiplicity of equilibria, strategic complementarity, asym- metric information.

Price policies and Price dispersion in the private healthcare insurance industry: The Catalan case

We present an overlapping generations model that explains price dispersion among Catalonian healthcare insurance firms. The model shows that firms with different premium policies can coexist. Furthermore, if interest rates are low, firms that apply equal premium to all insureds can charge higher average prices than insurers that set premiums according to the risk of insured. Economic theory, health insurance, health economics.

Anisotropic dispersion, space competition, and the slowdown of the Neolithic transition

The front speed of the Neolithic (farmer) spread in Europe decreased as it reached Northern latitudes, where the Mesolithic (huntergatherer) population density was higher. Here, we describe a reaction diffusion model with (i) an anisotropic dispersion kernel depending on the Mesolithicpopulation density gradient and (ii) a modified population growth equation. Both effects are related to the space available for the Neolithic population. The model is able to explain the slowdown of the Neolithic front as observed from archaeological data

Hints for a fast precessing relativistic radio jet in LS I+61·303

Here we discuss two consecutive MERLIN observations of the X-ray binary LS I +61◦303. The first observation shows a double-sided jet extending up to about 200 AU on both sides of a central source. The jet shows a bent S-shaped struct ure similar to the one displayed by the well-known precessing jet of SS 433. The precession suggested in the first MERLIN image becomes evident in the second one, showing a one-sided bent jet significantly rotated with respect to the jet of the day before. We conclude that the derived precession of the relativistic (β=0.6) jet explains puzzling previous VLBI results. Moreover , the fact that the precession is fast could be the explanation of the never understood short term (days) variability of the associated gamma-ray source 2CG 135 + 01 / 3EG J0241 + 6103.

Possible hot spots excited by the relativistic jets of Cygnus X-3

We present the results of a deep search for associated radio features in the vicinity of the microquasar Cygnus X-3. The motivation behind is to find out evidence for interaction between its relativistic jets and the surrounding interstellar medium, which could eventually allow us to perform calorimetry of the total energy released by this microquasar during its flaring lifetime. Remarkably, two radio sources with mJy emission level at centimeter wavelengths have been detected in excellent alignment with the position angle of the inner radio jets. We propose that these objects could be the hot spots where the relativitic outflow collides with the ambient gas in analogy with Fanaroff-Riley II radio galaxies. These candidate hot spots are within a few arc-minutes of Cygnus X-3 and, if physically related, the full linear extent of the jet would reach tens of parsecs. We discuss here the evidence currently available to support this hypothesis based on both archival data and our own observations.

Bulk-plasmon dispersion relations in metals

Using an extended-random-phase-approximation sum-rule technique, we have investigated the bulk-plasmon dispersion relation, incorporating in a simple way exchange and correlation effects within the jellium model. The results obtained are compared with recent experimental findings. The key role played by exchange and correlation effects in improving the agreement between theory and experiment is stressed. The static polarizability has also been calculated as a function of q. The formulas can be easily modified to incorporate band-structure effects (through an intraband electron effective mass) and core-polarization effects (through a static dielectric constant).

Nuclear curvature energy in relativistic models

The difficulties arising in the calculation of the nuclear curvature energy are analyzed in detail, especially with reference to relativistic models. It is underlined that the implicit dependence on curvature of the quantal wave functions is directly accessible only in a semiclassical framework. It is shown that also in the relativistic models quantal and semiclassical calculations of the curvature energy are in good agreement.

Variational Wigner-Kirkwood approach to relativistic mean field theory

The recently developed variational Wigner-Kirkwood approach is extended to the relativistic mean field theory for finite nuclei. A numerical application to the calculation of the surface energy coefficient in semi-infinite nuclear matter is presented. The new method is contrasted with the standard density functional theory and the fully quantal approach.

Effects of new nonlinear couplings in relativistic effective field theory

We extend the relativistic mean field theory model of Sugahara and Toki by adding new couplings suggested by modern effective field theories. An improved set of parameters is developed with the goal to test the ability of the models based on effective field theory to describe the properties of finite nuclei and, at the same time, to be consistent with the trends of Dirac-Brueckner-Hartree-Fock calculations at densities away from the saturation region. We compare our calculations with other relativistic nuclear force parameters for various nuclear phenomena.