Stable sunspot equilibria in a cash-in-advance economy

We analyze a monetary model with flexible labor supply, cash-inadvance constraints and seigniorage-financed government deficits. If the intertemporal elasticity of substitution of labor is greater than one, there are two steady states, one determinate and the other indeterminate. If the elasticity is less than one, there is a unique steady state, which can be indeterminate. Only in the latter case do there exist sunspot equilibria that are stable under adaptive learning. A sufficient reduction in government purchases can in many cases eliminate the sunspot equilibria while raising consumption/labor taxes even enough to balance the budget may fail to achieve determinacy.

Constraints and non-existence of rational expectations equilibria

In this article we show that in the presence of trading constraints, such as short sale constraints, the standard definition of a Rational Expectations Equilibrium allows for equilibrium prices that reveal information unknown to any active trader in the market. We propose a new definition of the Rational Expectations Equilibrium that incorporates a stronger measurability condition than measurability with respect to the join of the information sets of the agents and give an example of non-existence of equilibrium. The example is robust to perturbations on the data of the economy and the introduction of new assets.

Job search and asset accumulation under borrowing constraints

In this paper I show how borrowing constraints and job search interact.I fit a dynamic model to data from the National Longitudinal Survey(1979-cohort) and show that borrowing constraints are significant. Agentswith more initial assets and more access to credit attain higher wagesfor several periods after high school graduation. The unemployed maintaintheir consumption by running down their assets, while the employed saveto buffer against future unemployment spells. I also show that, unlikein models with exogenous income streams, unemployment transfers, byallowing agents to attain higher wages do not 'crowd out' but increasesaving.

GalaxyDefenders: desenvolupament d'un side-scrolling shooter per iOS

Aquest projecte neix del interés personal de l’autor per a la indústria dels videojocs. El principal objectiu de l’aplicació és esdevenir un joc complet mitjançant l’ús de tècniques clàssicament empleades en el desenvolupament de jocs en dues dimensions de manera que la experiència i tècniques adquirides sigui el més reutilitzable possible.

Lobbying, political competition, and local land supply: recent evidence from Spain

We analyze whether local land supply is influenced by the degree of political competition, and interpret the findings as being indicative of the influence wielded by land development lobbies. We use a new database including both political and land supply data for more than 2,000 Spanish municipalities for the period 2003-2007. In Spain, land use policies are largely a local responsibility with municipalities having periodically to pass compre- hensive land use plans. The main policy variable in these plans, and the one analyzed here, is the amount of land classified for potential development. We measure local political competition as the margin of victory of the incumbent government. We instrument this variable using the number of votes obtained by parties represented in local government when standing at the first national legislative elections following the re-establishment of democracy, and the number of votes they actually obtained regionally at the national legislative elections. The results indicate that stiffer political competition does indeed reduce the amount of new land designated for development. This effect is found to be most marked in suburbs, in towns with a high percent of commuters and homeowners, and in municipalities governed by the left.

Application of a floating well concept to a latch-up-free, low-cost, smart power high-side switch technology

The aim of this brief is to present an original design methodology that permits implementing latch-up-free smart power circuits on a very simple, cost-effective technology. The basic concept used for this purpose is letting float the wells of the MOS transistors most susceptible to initiate latch-up.

Lobbying, political competition, and local land supply: recent evidence from Spain

We analyze whether local land supply is influenced by the degree of political competition, and interpret the findings as being indicative of the influence wielded by land development lobbies. We use a new database including both political and land supply data for more than 2,000 Spanish municipalities for the period 2003-2007. In Spain, land use policies are largely a local responsibility with municipalities having periodically to pass compre- hensive land use plans. The main policy variable in these plans, and the one analyzed here, is the amount of land classified for potential development. We measure local political competition as the margin of victory of the incumbent government. We instrument this variable using the number of votes obtained by parties represented in local government when standing at the first national legislative elections following the re-establishment of democracy, and the number of votes they actually obtained regionally at the national legislative elections. The results indicate that stiffer political competition does indeed reduce the amount of new land designated for development. This effect is found to be most marked in suburbs, in towns with a high percent of commuters and homeowners, and in municipalities governed by the left.

Side scan sonar image and geologic interpretation of the Ria de Pontevedra seafloor (Galicia, NW Spain).

High-resolution side scan sonar has been used for mapping the seafloor of the Ría de Pontevedra. Four backscatter patterns have been mapped within the Ría: (1) Pattern with isolated reflections, correlated with granite and metamorphic outcrops and located close to the coastal prominence and Ons and Onza Islands. (2) Pattern of strong reflectivity usually located around the basement outcrops and near the coastline and produced by coarse-grained sediment. (3) Pattern of weak backscatter is correlated with fine sand to mud and comprising large areas in the central and deep part of the Ría, where the bottom currents are weak. It is generally featureless, except where pockmarks and anthropogenic features are present. (4) Patches of strong and weak backscatter are located in the boundary between coarse and fine-grained sediments and they are due to the effect of strong bottom currents. The presence of megaripples associated to both patterns of strong reflectivity and sedimentary patches indicate bedload transport of sediment during high energy conditions (storms). Side scan sonar records and supplementary bathymetry, bottom samples and hydrodynamic data reveal that the distribution of seafloor sediment is strongly related to oceanographic processes and the particular morphology and topography of the Ría.

Hamiltonian and Lagrangian constraints of the bosonic string

We study the Hamiltonian and Lagrangian constraints of the Polyakov string. The gauge fixing at the Hamiltonian and Lagrangian level is also studied.

Constraints on additional Z' gauge bosons from a precise measurement of the Z mass

We analyze the constraints on the mass and mixing of a superstring-inspired E6 Z' neutral gauge boson that follow from the recent precise Z mass measurements and show that they depend very sensitively on the assumed value of the W mass and also, to a lesser extent, on the top-quark mass.

Side-branch growth in two-dimensional dendrits. Part II: Phase-field model

The development of side-branching in solidifying dendrites in a regime of large values of the Peclet number is studied by means of a phase-field model. We have compared our numerical results with experiments of the preceding paper and we obtain good qualitative agreement. The growth rate of each side branch shows a power-law behavior from the early stages of its life. From their birth, branches which finally succeed in the competition process of side-branching development have a greater growth exponent than branches which are stopped. Coarsening of branches is entirely defined by their geometrical position relative to their dominant neighbors. The winner branches escape from the diffusive field of the main dendrite and become independent dendrites.

Higher order Lagrangian systems: Geometric structures, Dynamics, and Constraints

In order to study the connections between Lagrangian and Hamiltonian formalisms constructed from aperhaps singularhigher-order Lagrangian, some geometric structures are constructed. Intermediate spaces between those of Lagrangian and Hamiltonian formalisms, partial Ostrogradskiis transformations and unambiguous evolution operators connecting these spaces are intrinsically defined, and some of their properties studied. Equations of motion, constraints, and arbitrary functions of Lagrangian and Hamiltonian formalisms are thoroughly studied. In particular, all the Lagrangian constraints are obtained from the Hamiltonian ones. Once the gauge transformations are taken into account, the true number of degrees of freedom is obtained, both in the Lagrangian and Hamiltonian formalisms, and also in all the intermediate formalisms herein defined.