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.

La transitividad causal a escena

Lewis (2000) menciona que todo contraejemplo de la transitividad de las causas se enmarca en un esquema en el que hay dos bandos, negro y rojo, en donde una movida del bando negro que es hecha presuntamente para defenderse, ocasiona que el bando rojo haga cierta movida que le da la victoria. Finalmente los contraejemplos mostrarían que el movimiento del bando negro causó su propia derrota

Comentarios al principio de clausura causal y la causación internivel

En este trabajo analizo diferentes versiones del principio de clausura causal del mundo físico e Intento mostrar que mientras que algunas versiones presuponen algún tipo de parálisis metodológica otras recurren a cierta circularidad o bien tienen como consecuencia expedirse sobre cienos aspectos empíricos del mundo. Finalmente se analiza el concepto de historia causal de un evento para mostrar que buena parte de la discusión presupone que es posible delimitar qué episodios forman parte de la historia causal y cuáles no, sobre la base de suposiciones de conexión causal física, suposición que los defensores del principio causal nunca hacen explícita, y que, en caso de tomarse como guía para esa exploración la teoría contrafáctica, los resultados distan enormemente de los que esperan encontrar tales defensores

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

Revisiting the asymptotic dynamics of General Relativity on AdS3_3

The dual dynamics of Einstein gravity on AdS$_3$ supplemented with boundary conditions of KdV-type is identified. It corresponds to a two-dimensional field theory at the boundary, described by a novel action principle whose field equations are given by two copies of the "potential modified KdV equation". The asymptotic symmetries then transmute into the global Noether symmetries of the dual action, giving rise to an infinite set of commuting conserved charges, implying the integrability of the system. Noteworthy, the theory at the boundary is non-relativistic and possesses anisotropic scaling of Lifshitz type.Comment: 18 page

Reaction Kinetics in the Production of Pd Nanoparticles in Reverse Microemulsions. Effect on Particle Size

In the synthesis of metallic nanoparticles in microemulsions, we hypothesized that particle size is mainly controlled by the reaction rate. Thus, the changes observed on the particle sizes as reaction conditions, such as concentrations, temperature, type of surfactant used, etc., are varied should not be correlated directly to the modification of those conditions but indirectly to the changes they produce on the reaction rates. By means of time resolved UV-vis spectroscopy, we measured the reaction rates in the production of Pd nanoparticles inside microemulsions at different reactant concentrations, keeping all the other parameters constant. The measured reaction rates were then correlated with the particle sizes measured by transmission electron microscopy (TEM). We found that nanoparticle size increases linearly as the reaction rates increases, independently of the actual reactant concentrations. We proposed that the kinetics is controlled mainly by the diffusion of the reducing agent through the surfactant monolayer covering the microemulsion membrane. With this model, we predicted that particle size should depend indirectly, via the reaction kinetics, on the micelle radius (v0 ~ r^-3), the water volume (v0~vw^3) and the total microemulsion volume (v0~vT^-3), and temperature (Arrhenius). Some of these predictions were explored in this article

The Simulation Model as a Causal Explanation Generator

Here we enrich Paul Weirich’s thesis holding that a simulation model can create knowledge in the form of causal explanations. We sustain the validity of exporting results from the model to the modelized world in virtue of the similarity between model and world, which is analyzable in terms of partial identity of structure, eliminating the superficial similarity that repeats empirical results by adjusting data via calibration. The structure of relations rescues from the world critical results to analyze such similarity, as so certain properties which condition the kind of relations held between the elements of the model representing entities of the world

Gardenfors, el arraigo de las creencias y el cambio teórico

En su libro Knowledge in Flux, Peter Gardenfors nos presenta un análisis formal de los sistemas de creencias y de sus posibles cambios. En particular nos interesa remarcar aquí algunos puntos de su propuesta con la finalidad de poder emplearlos para una mejor comprensión del cambio científico, entendiendo a éste fundamentalmente como un cambio de creencias y no tanto como un proceso ligado a la justificación lógica basada en los grados de confirmación o de falsabilidad que una teoría pueda tener. En la sección siguiente esbozamos algunas de las nociones de la propuesta de Gardenfors y en las subsiguientes presentamos algunas críticas a su propuesta y sugerimos algunas ideas que al ser articuladas con su propuesta, permitirían una mejor evaluación de la magnitud del cambio científico