Inferring Agent Behavior and Economic Information, with Free Entry and Exit of Firms

This article proposes an identity regarding economic outcomes when producers maximize profits, with free entry and exit of firms. The identity links consumer and producer theory and leads to several results that contribute to understand what should -and should not- be expected under the assumptions made, from the behavior of firms and households, and from the technology of a firm. Given that unit prices are usually known, the identity also allows to infer the value of a range of economic variables, when reasonable information is available on the price elasticity of the residual demand, the marginal revenue associated to the residual demand, the marginal cost or the elasticity of scale.Price elasticity of demand, elasticity of scale, free entry and exit of firms, homogeneous production function.

Elementos geomorfológico-cuantitativos del piedemonte nororiental del volcán Nevado de Toluca

A partir de un análisis cuantitativo y morfométrico, se determina la geodinámica del piedemonte nororiental del volcán Nevado de Toluca. Se destaca la relación entre el material, las formas heredadas y la energía que dinamiza el noreste del volcán

Metodología para la evaluación morfoedáfica en sistemas de laderas en zonas templadas

Bajo el enfoque de la geografía del paisaje y desde una perspectiva original y de integración se presenta una metodología de análisis morfoedáfico. El proceso metodológico integra razonamientos del análisis geomorfológico y de la geografía del suelo, los cuales se expresan e interpretan desde un punto de vista holístico-territorial. El problema de investigación se centra en la resolución de fases terminales de evaluación geomorfológica y edáfica, y se aplica en tres sistemas de laderas localizados en el Sistema Volcánico Transversal. El producto final de la investigación se concentra en un mapa morfoedáfico que representa resultados de los índices de desarrollo geomorfológico y de la relación de equilibrio edáfico con una leyenda que unifica los criterios de análisis

Morfoedafogénesis: un concepto renovado en el estudio del paisaje

Se presenta un concepto renovadode morfoedafogénesis sustentado en laaplicación y medición de indicadores delrelieve y del suelo retomados desde unaperspectiva que integra a la geomorfología y lageografía del suelo.Basado en una investigación que propone unmétodo original de evaluación morfoedáficaen sistemas de laderas, se plantea la relaciónentre dos disciplinas geográficas que permitenla evaluación presente y futura del paisajedesde la capacidad de acogida, potencial deuso, tendencias, así como la identificación ycorrección de impactos desde una perspectivaholística y paramétrica

Representations and Identities for homogeneous Technologies

Using up to nine different ways to represent a homogeneous technology, this paper proves explicit one to one identities between most of those different representations of a technology, outlining the homogeneity properties of each representation. These identities, which allow to shift from one representation of a technology to another -and which are summarized in a matrix of identities - can be useful since they provide a tool to obtain explicit functional forms forhomogeneous technologies. They can also be useful to simplify computational procedures when different representations of a technology are needed. Finally, the document also refers explicitly to some aspects of producer theory that are often neglected or treated in a marginal way in the literature, such as the inverse supply, the non conditional cost and the inverse input demandfunctions.Identities, homogeneous production functions and firm theory

Conflict and Uncertainty: A Dynamic Approach

Most of the conflict theory papers have used a one-shot game set-up. This does not correspond to reality and is certainly incapable of modeling real conflict situations. We propose a dynamic model with N-agents in an infinite time frame which allow us to adequately analyze conflicts. The dynamic aspects of the conflict come at least from two sources: first, the preferences on the good in dispute are not static; second, agentsin conflict can influence the future of the conflict by making investment in conflict's technology. We use a simple deterministic rule that defines the evolution of the subjective valuation for the good in dispute according to the results obtained by the agents in the recent past. During each period the realization of stochastic variables of the nature's states induces uncertainty in the game. The model is a theoretical approach that can be applied to evaluate the role of uncertainty and valuations' evolution on the optimal choices of forward-looking economic agents that seek to appropriate a share of a divisible resource.Conflict Theory, Dynamic Economic Model, Uncertainty

Disclosure and liquidity

The purpose of this paper is to test empirically the relationship between two important concepts: disclosure and liquidity. Using a sample of Spanish quoted firms between 1994 and 2000 we show that the estimation of the relationship between disclosure and liquidity depends crucially on two factors: a) the multidimensionality of the concept of liquidity; b) the use of an econometric methodology that deals properly with the features of the sample used. However the use of the Amihud (2002) illiquidity measure provides evidence in favour of a positive relationship between disclosure and liquidity

Strategic Behaviour, Resource Valuation and Competition in Electricity Markets

By means of a suitable Bayesian game we study spot electricity markets from a structural point of view. We address the problem of individual and aggregate eficciency and we show how to value water from market observables. We compare the former to engineering methods and apply our methodology to Colombian spot electricity market. Our results show that big gas and small hydro plants overbid, resources are undervalued by engineering costs and aggregate costs would have been considerably smaller if agents had played optimally. Revealed costs show a substantial gain in eficciency in the Vickrey auction compared to the actual uniform auction.Multi-unit auctions, Oligopoly, electricity markets

Identities For Homogeneous Utility Functions

Using a homogeneous and continuous utility function that represents a household's preferences, this paper proves explicit identities between most of the different objects that arise from the utility maximization and the expenditure minimization problems. The paper also outlines the homogeneity properties of each object. Finally, we show explicit algebraic ways to go from the indirect utility function to the expenditure function and from the Marshallian demand to the Hicksian demand and vice versa, without the need of any other function, thus simplifying the integrability problem avoiding the use of differential equations.Identities, homogeneous utility functions and household theory.

CFD study of two-phase flows in hypergravity conditions with OpenFOAM

Avui en dia ens trobem a l’epoca m ` es important de l’espai i de l’aire, lo qual ha portat a ´ que la tecnologia s’hagi vist obligada a desenvolupar-se fins al punt de poder ser utilitzada en condicions gravitacionals que no es troben a la superfície de la Terra. L’aplicacio de ´ sistemes de fluids bifasics en avions, per ` o sobretot en naus espacials ` es de gran inter ´ es` per al sector a causa dels seus avantatges, entre els quals destaquen: la reduccio de pes, ´ millora del rendiment i millores en l’eficiencia dels sistemes, totes elles en comparaci ` oámb fluids monofasics. Els exemples m ` es notables on s’utilitzen els fluids bif ´ asics s ` on els ´ bioreactors espacials, contactors químics de gas-líquid, sistemes de propulsio, sistemes ´ de gestio t ´ ermica, incloent el refredament de combustible o electr ` onica, i els sistemes de ` suport de vida espacials. Tot i la gran varietat d’aplicacions tecnologiques, hi ha molt pocs èstudis en condicions d’hipergravetat i la majoria d’ells es centren en fabricar components de naus lo mes resistents possible. Per tant, la investigaci ´ o de flux de fluids en condicions ´ d’hipergravetat es una ´ area molt desconeguda que requereix m ` es investigaci ´ o. ´ En Francesc Sunol i en Ricard Gonz ˜ alez-Cinca van realitzar fa uns anys un estudi experi- ´ mental sobre els efectes de la gravetat en la formacio de bombolles i el seu ascens dins ´ d’un líquid de baixa viscositat (aigua destil·lada). Aquest estudi es va dur a terme en l’entorn d’hipergravetat artificial generat per la centrifugadora de gran diametre de l’Ag ` encia ` Espacial Europea. Així doncs, en aquest TFG s’ha reprodu¨ıt l’esmentada investigacioámb un programa CFD anomenat OpenFOAM i amb dos objectius principals: analitzar els mateixos aspectes relatius a la formacio de bombolles i el seu ascens, ja que el seu com- ´ portament canvia a mesura que augmenta el nivell de gravetat, i comparar els resultats obtinguts a partir de les simulacions numeriques amb els resultats de l’experiment previ, ` per tal de validar el programa per aquest us. ´ Aquest projecte te una part important que consisteix en validacions, on hem estudiat els ´ parametres m ` es importants per a les simulacions, com ara: l’angle de contacte del fluid í la convergencia de la malla i del pas de temps. A m ` es de l’an ´ alisi del transitori entre ` dues bombolles consecutives, i el proces de formaci ´ o de bombolles en gravetat normal i én condicions d’hipergravetat. Despres d’aquestes validacions es van realitzar les proves ´ finals per mesurar el volum i la velocitat d’ascens de les bombolles. Les simulacions corresponents es van definir en diferents condicions d’hipergravetat, per a tres velocitats de injeccio de gas: ´ 0,03m/s, 0,06m/s i 0,1m/s. Finalment, comparant els resultats d’OpenFOAM amb els obtinguts de la recerca anterior, es pot afirmar que el programa CFD utilitzat pot reproduir un problema de flux de fluids amb exit. El despreniment de la bombolla del capil ` ·lar esta determinat per les tensions ` superficials i per la forc¸a de flotabilitat, encara que per a valors de gravetat mes alts aquest ´ proces s’accelera. El posterior ascens de la bombolla segueix una traject ´ oria en zig-zag ` que es desestabilitza i accelera a mesura que els efectes gravitacionals s ´ on m ´ es grans, el ´ que comporta una variacio de l’amplitud i la freq ´ u¨encia de l’oscil ` ·lacio, com s’observa enNowadays we are in the greatest space and air era ever, in which technology has been forced to develop up to the point of being applied in gravity conditions that cannot be found on Earth surface. The application of two-phase fluid systems in spacecraft are of great interest to this sector due to its advantages, including: weigh reduction, enhanced performance and efficiency improvement, all of them in comparison with mono-phase fluids. The most remarkable examples where are used biphasic fluids are space bioreactors, chemical gas-liquid contactors, propulsion systems, thermal management systems including fuel or electronics cooling, and spatial life-support systems. Even though the wide variety of technological applications, there are very few hypergravity studies and most of them focus on making spacecraft’s components the more resistant as possible. Therefore, the fluid flow research in hypergravity conditions is a very unknown area that requires further investigation. Some years ago Francesc Sunol and Ricard Gonz ˜ alez-Cinca performed an experimental ´ analysis of the effects of gravity on bubble formation and rise in a low viscosity liquid (distilled-water). This study was carried in the hypergravity environment generated by the large diameter centrifuge of the European Space Agency. So, in the work presented it has been reproduced the mentioned research with a CFD software called OpenFOAM with two main objectives: analyse the same aspects regarding the bubble formation and rise processes, since its behaviour changes as the gravity level increases, and compare the results obtained from the numerical simulations with the previous ones, in order to validate the CFD program for this use. This project has an important part that consists in validations, where we have studied the most important parameters for the simulations, such as: the contact angle of the fluid and the convergence of the mesh and time step. In addition to the analysis of the transient between two consecutive bubbles, and the bubble formation process in normal gravity and in hypergravity conditions. Then, we performed the final tests to study the bubble rise velocity and volume. The corresponding simulations were set in different hypergravity conditions, for three gas injection velocities: 0.03m/s, 0.06m/s and 0.1m/s. Finally, comparing the OpenFOAM results with the ones obtained in the previous research, it can be stated that CFD software can reproduce a fluid flow experiment successfully. The detachment of the bubble from the capillary is determined by surface tensions and buoyancy force, although at higher gravity levels this process is accelerated. Posterior bubble rise follows a zig-zag path that is destabilized and accelerated as gravitational effects increase, which leads to a variation in the oscillation amplitude and frequency, as shown in [1]