Notes on the Suboptimality Result of J. D. Geanakoplos and H. M. Polemarchakis (1986)

J. D. Geanakoplos and H. M. Polemarchakis (1986) prove the generic constrained suboptimality of equilibrium allocations in two period economies with incomplete markets. They perturb asset prices at equilibrium when the degree of market incompleteness equals one. Since prices do not parameterize the economy, a generic result cannot be obtained in such a way. These notes provide a detailed version of their proof in which utilities and endowments are perturbed.incomplete asset markets constrained suboptimality, transversality theory.

Retail policy and local development in metropolitan space: Some lessons from the case of Tres Cantos (Madrid) new town

Urban development, as comprehensive concept, involves a wide set of components, and it would imply a reasonably well balanced growth of differents urban functions and activities. The strong spatial competition between firms and localities in metropolitan areas yields unequal spatial impacts on the growth of retail activities. An usual scenery in western suburban areas is the presence of great retail facilities dominating the surrounding market. This situation negatively affects to little and lower-medium settlements that, in this way, play a dominated role, seen as undesirable by local agents and provoking emergent policies. Grounded on this basis this paper tackles the case of a lower medium new town located near Madrid (Tres Cantos), where the local government and retail organisations have reacted against its dominated role and have promoted a set of measures to overcome the problems detected, mainly the local consumer leakeage, the limited success or failure of new retail firms and, in a wider sense, the underdevelopment of the local retail sector. The study describes the main findings of a wider report conducted to evaluate the implemented measures, its effectiveness and the local market agents' valuation. This experience also illustrates the problems of objective setting and policy implementation, when the public and the private sector participate in a joint decision. Keywords: new town development, retail system, urban retail policy Suitable for Conference Themes: D (Metropolitan processes and policies) or parhaps, H (Services, small enterprises ....)

Strategic Information Acquisition in Networked Groups with "Informational Spillovers"

This paper develops a model of costly information acquisition by agents who are connected through a network. For a exogenously given network, each agent decides first on information acquisition from his neighbors and then, after processing the information acquired, takes an action. Each agent is concerned about the extent to which other agents align their actions with the underlying state. A new equilibrium notion, which is in the spirit of perfect Bayesian equilibrium, is proposed to analyze information acquisition decisions within networked groups. This equilibrium notion allows each agent to compute, when deciding about information acquisition, the extent to which changes in his information acquisition decision will affect his own perception of future expected payos. Agents anticipate and incorporate such changes in their information acquisition decisions. Both the efficient and the equilibrium information acquisition proles are characterized and the compatibility between them is related to the density of the network.Incomplete Information, Information Acquisition, Communication Networks, Informational Spillovers, Coordination

Notes on the Suboptimality Result by J. D. Geanakoplos and H. M. Polemarchakis (1986)

J. D. Geanakoplos and H. M. Polemarchakis (1986) prove the generic constrained suboptimality of equilibrium allocations in two period economies with incomplete markets. They perturb asset prices at equilibrium when the degree of market incompleteness equals one. However, since prices are not fundamentals that parameterize the economy, a generic result cannot be obtained in such a way. In these notes we provide complete and detailed version of their proof in which the arguments do not depend on the dimension of the market incompleteness and in which utilities and endowments are perturbed.Incomplete Asset Markets, Constrained Suboptimality, Transversality Theory

Communication and comparative rephotography. Architectural evolution, the case of Fez and Grenade

Poder contar con la fotografía como medio de investigación y posteriormente para poder establecer la comunicación de los aspectos desarrollados en temas de arquitectura, patrimonio y urbanismo es un potencial importante en la preservación de la memoria e identidad de un pueblo. En este caso de temáticas sobre arquitectura y urbanismo, con mayor importancia porque ayuda a comprender en un primer nivel la evolución de la arquitectura en un contexto geográfico e histórico concreto, que en el caso que nos ocupa de la ciudad marroquí de Fez evidencia en un segundo nivel de análisis la reconstrucción ideológica que constituye una gran parte de imaginarios, reales o inventados, con el atrezzo que los recargos estéticos producen, de carácter acusadamente orientalistas. El caso de la ciudad marroquí de Fez no es el único, pasa en otras ciudades de todo el mundo, como es el caso de la ciudad española de Granada, en parte hermanada históricamente por su pasado, también por las personas que la habitaron, descendientes de esos granadinos expulsados a finales del siglo XV que en su mayoría viajaron a la ciudad de Fez. El análisis del medio fotográfico es el utilizado para la realización de este trabajo, fundamentado en la primera mitad del siglo XX que coincide con el protectorado franco- español, época de primera modernización del país, por medio de las fotografías contenidas en las tarjetas postales que ayudaran a comprender parte de esa reconstrucción mítica, donde la mirada externa tiende a crear realidades imaginadas, o imaginarias, sobre la identidad de un pueblo.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Towards Odor-Sensitive Mobile Robots

J. Monroy, J. Gonzalez-Jimenez, "Towards Odor-Sensitive Mobile Robots", Electronic Nose Technologies and Advances in Machine Olfaction, IGI Global, pp. 244--263, 2018, doi:10.4018/978-1-5225-3862-2.ch012 Versión preprint, con permiso del editorOut of all the components of a mobile robot, its sensorial system is undoubtedly among the most critical ones when operating in real environments. Until now, these sensorial systems mostly relied on range sensors (laser scanner, sonar, active triangulation) and cameras. While electronic noses have barely been employed, they can provide a complementary sensory information, vital for some applications, as with humans. This chapter analyzes the motivation of providing a robot with gas-sensing capabilities and also reviews some of the hurdles that are preventing smell from achieving the importance of other sensing modalities in robotics. The achievements made so far are reviewed to illustrate the current status on the three main fields within robotics olfaction: the classification of volatile substances, the spatial estimation of the gas dispersion from sparse measurements, and the localization of the gas source within a known environment

Convex Global 3D Registration with Lagrangian Duality

The registration of 3D models by a Euclidean transformation is a fundamental task at the core of many application in computer vision. This problem is non-convex due to the presence of rotational constraints, making traditional local optimization methods prone to getting stuck in local minima. This paper addresses finding the globally optimal transformation in various 3D registration problems by a unified formulation that integrates common geometric registration modalities (namely point-to-point, point-to-line and point-to-plane). This formulation renders the optimization problem independent of both the number and nature of the correspondences. The main novelty of our proposal is the introduction of a strengthened Lagrangian dual relaxation for this problem, which surpasses previous similar approaches [32] in effectiveness. In fact, even though with no theoretical guarantees, exhaustive empirical evaluation in both synthetic and real experiments always resulted on a tight relaxation that allowed to recover a guaranteed globally optimal solution by exploiting duality theory. Thus, our approach allows for effectively solving the 3D registration with global optimality guarantees while running at a fraction of the time for the state-of-the-art alternative [34], based on a more computationally intensive Branch and Bound method.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dark energy: the absolute electric potential of the universe

Is there an absolute cosmic electric potential?. The recent discovery of the accelerated expansion of the universe could be indicating that this is certainly the case. In this essay we show that the consistency of the covariant and gauge invariant theory of electromagnetism is truly questionable when considered on cosmological scales. Out of the four components of the electromagnetic field, Maxwell's theory only contains two physical degrees of freedom. However, in the presence of gravity, one of the "unphysical" states cannot be consistently eliminated, thus becoming real. This third polarization state is completely decoupled from charged matter, but can be excited gravitationally thus breaking gauge invariance. On large scales the new state can be seen as a homogeneous cosmic electric potential, whose energy density behaves as a cosmological constant.Comment: 9 pages, 2 figures. Essay selected for "Honorable Mention" in the 2009 Awards for Essays on Gravitation (Gravity Research Foundation

Initialization of 3D Pose Graph Optimization using Lagrangian duality

Pose Graph Optimization (PGO) is the de facto choice to solve the trajectory of an agent in Simultaneous Localization and Mapping (SLAM). The Maximum Likelihood Estimation (MLE) for PGO is a non-convex problem for which no known technique is able to guarantee a globally optimal solution under general conditions. In recent years, Lagrangian duality has proved suitable to provide good, frequently tight relaxations of the hard PGO problem through convex Semidefinite Programming (SDP). In this work, we build from the state-of-the-art Lagrangian relaxation [1] and contribute a complete recovery procedure that, given the (tractable) optimal solution of the relaxation, provides either the optimal MLE solution if the relaxation is tight, or a remarkably good feasible guess if the relaxation is non-tight, which occurs in specially challenging PGO problems (very noisy observations, low graph connectivity, etc.). In the latter case, when used for initialization of local iterative methods, our approach outperforms other state-ofthe- art approaches converging to better solutions. We support our claims with extensive experiments.University of Malaga travel grant, the Spanish grant program FPU14/06098 and the project PROMOVE (DPI2014-55826-R), funded by the Spanish Government and the "European Regional Development Fund". Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

The determinants of pricing in pharmaceuticals : are U.S. prices really higher than those of Canada?

This paper studies price determination in pharmaceutical markets using data for 25 countries, six years and a comprehensive list of products from the MIDAS IMS database. We show that market power and the quality of the product has a significantly positive impact of prices. The nationality of the producer appears to have a small and often insignificant impact on prices, which suggests that countries which regulates prices have relatively little power to do it in a way that advances narrow national interest. We produce a theoretical explanation for this phenomenon based on the fact that low negotiated prices in a country would have a knock-on effect in other markets, and is thus strongly resisted by producers. Another key finding is that the U.S. has prices that are not significantly higher than those of countries with similar income levels. This, together with the former observation on the effect of the nationality of producers casts doubt on the ability of countries to pursue “free-riding" regulation.