Preferred suppliers in auction markets

In a procurement setting, this paper examines agreements between a buyer and one of the suppliers which would increase their joint surplus. The provisions of such agreements depend on the buyer's ability to design the rules of the final procurement auction. When the buyer has no such ability, their joint surplus can be increased by an agreement which grants to the preferred supplier a right-of-first-refusal on the lowest price offer from the other suppliers. When the buyer does have this ability, one agreement which maximizes their joint surplus includes a revelation game for the cost of the preferred supplier and a reserve price in the procurement auction based on that cost.

Une stratégie de développement durable pour l´eurorégion Pyrénées-Méditerranée: orientations de base

L'estudi té per objecte formular els requisits necessaris per posar en marxa una estratègia per al desenvolupament sostenible de l'Euroregió Pirineus-Mediterrània. Aquest és un projecte de cooperació transfronterera regional promogut per l'expresident de la Generalitat, Honorable Sr Pasqual Maragall, que, a més de Catalunya, inclou Aragó, Illes Balears, Llenguadoc-Rosselló i Migdia-Pirineus. A la Unió Europea hi ha més de 70 euroregions, que ha estat creades per regions o entitats locals, o ambdós

Effects of SrTiO3 capping in La2/3Ca1/3MnO3 electrodes of different orientations

We report on the study of the structural, magnetic, and electronic properties of SrTiO3 capped La2/3Ca1/3MnO3 electrodes grown on (001) and (110) SrTiO3 substrates. Magnetic properties of the (001) and (110) capped electrodes evolve differently when the capping layer thickness increases, revealing a reduction of the saturation magnetization for the (001) ones. Electronic properties are studied combining 55Mn nuclear magnetic resonance (NMR) and x-ray photoemission spectroscopy (XPS). NMR experiments highlight that electronic phase separation in the (001) electrodes is enhanced by the presence of the SrTiO3 capping layer and XPS measurements show that the electronic state of interfacial Mn ions from (001) electrode is more sensitive to the capping layer.

Identifying the preferred subset of enzymatic profiles in nonlinear kinetic metabolic models via multiobjective global optimization and pareto filters

Optimization models in metabolic engineering and systems biology focus typically on optimizing a unique criterion, usually the synthesis rate of a metabolite of interest or the rate of growth. Connectivity and non-linear regulatory effects, however, make it necessary to consider multiple objectives in order to identify useful strategies that balance out different metabolic issues. This is a fundamental aspect, as optimization of maximum yield in a given condition may involve unrealistic values in other key processes. Due to the difficulties associated with detailed non-linear models, analysis using stoichiometric descriptions and linear optimization methods have become rather popular in systems biology. However, despite being useful, these approaches fail in capturing the intrinsic nonlinear nature of the underlying metabolic systems and the regulatory signals involved. Targeting more complex biological systems requires the application of global optimization methods to non-linear representations. In this work we address the multi-objective global optimization of metabolic networks that are described by a special class of models based on the power-law formalism: the generalized mass action (GMA) representation. Our goal is to develop global optimization methods capable of efficiently dealing with several biological criteria simultaneously. In order to overcome the numerical difficulties of dealing with multiple criteria in the optimization, we propose a heuristic approach based on the epsilon constraint method that reduces the computational burden of generating a set of Pareto optimal alternatives, each achieving a unique combination of objectives values. To facilitate the post-optimal analysis of these solutions and narrow down their number prior to being tested in the laboratory, we explore the use of Pareto filters that identify the preferred subset of enzymatic profiles. We demonstrate the usefulness of our approach by means of a case study that optimizes the ethanol production in the fermentation of Saccharomyces cerevisiae.

Preferred Spatial Frequencies for Human Face Processing Are Associated with Optimal Class Discrimination in the Machine

Psychophysical studies suggest that humans preferentially use a narrow band of low spatial frequencies for face recognition. Here we asked whether artificial face recognition systems have an improved recognition performance at the same spatial frequencies as humans. To this end, we estimated recognition performance over a large database of face images by computing three discriminability measures: Fisher Linear Discriminant Analysis, Non-Parametric Discriminant Analysis, and Mutual Information. In order to address frequency dependence, discriminabilities were measured as a function of (filtered) image size. All three measures revealed a maximum at the same image sizes, where the spatial frequency content corresponds to the psychophysical found frequencies. Our results therefore support the notion that the critical band of spatial frequencies for face recognition in humans and machines follows from inherent properties of face images, and that the use of these frequencies is associated with optimal face recognition performance.

Social capital and government in the production of public goods

As a response to the rapidly growing empirical literature on social capital and the evidence of its correlation with government performance, we build a theoretical framework to study the interactions between social capital and government's action. This paper presents a model of homogeneous agents in an overlapping generations framework incorporating social capital as the values transmitted from parent to child. The government's role is to provide public goods. First, government expenditure is exogenously given. Then, it will be chosen at the preferred level of the representative agent. For both setups the equilibrium outcomes are characterized and the resulting dynamics studied. Briefly we include an analysis of the effect of productivity growth on the evolution of social capital. The results obtained caution caution against both the crowding out effect of the welfare state and the impact of sustained economic growth on social capital.

Bribe-proof rules in the division problem

The division problem consists of allocating an amount of a perfectly divisible good among a group of n agents with single-peaked preferences. A rule maps preference profiles into n shares of the amount to be allocated. A rule is bribe-proof if no group of agents can compensate another agent to misrepresent his preference and, after an appropriate redistribution of their shares, each obtain a strictly preferred share. We characterize all bribe-proof rules as the class of efficient, strategy-proof, and weak replacement monotonic rules. In addition, we identify the functional form of all bribe-proof and tops-only rules.

Preventive health care and payment systems to providers

Prevention has been a main issue of recent policy orientations in health care. This renews the interest on how different organizational designs and the definition of payment schemes to providers may affect the incentives to provide preventive health care. We present, both the normative and the positive analyses of the change from independent providers to integrated services. We show the evaluation of that change to depend on the particular way payment to providers is done. We focus on the externality resulting from referral decisions from primary to acute care providers. This makes our analysis complementary to most works in the literature allowing to address in a more direct way the issue of preventive health care.

Venture capital meets contract theory: risky claims or formal control?

This paper develops a theory of the joint allocation of formal control and cash-flow rights in venture capital deals. We argue that when the need for investor support calls for very high-powered outside claims, entrepreneurs should optimally retain formal control in order to avoid excessive interference. Hence, we predict that risky claims should be be negatively correlated to control rights, both along the life of a start-up and across deals. This challenges the idea that risky claims should a ways be associated to more formal control, and is in line with contractual terms increasingly used in venture capital, in corporate venturing and in partnership deals between biotech start-ups and large drug companies. The paper provides a theoretical explanation to some puzzling evidence documented in Gompers (1997) and Kaplan and Stromberg (2000), namely the inclusion in venture capital contracts of contingencies that trigger both a reduction in VC control and the conversion! of her preferred stocks into common stocks.

(When) would i lie to you? comment on? deception: the role of consequences?

This paper reconsiders the evidence on lying or deception presented in Gneezy (2005,American Economic Review). We argue that Gneezy?s data cannot reject the hipótesis that people are one of two kinds: either a person will never lie, or a person will lie whenever she prefers the outcome obtained by lying over the outcome obtained by telling the truth. This implies that so long as lying induces a preferred outcome over truth-telling, a person?s decisión of whether to lie may be completely insensitive to other changes in the induced outcomes, such as exactly how much she monetarily gains relative to how much she hurts an anonymous partner. We run new but similar experiments to those of Gneezy in order to test this hypothesis. We find that our data cannot reject this hypothesis either, but we also discover substantial differences in behavior between our sub jects and Gneezy?s sub jects.

Constrained school choice

Recently, several school districts in the US have adopted or consider adopting the Student-Optimal Stable Mechanism or the Top Trading Cycles Mechanism to assign children to public schools. There is clear evidence that for school districts that employ (variants of) the so-called Boston Mechanism the transition would lead to efficiency gains. The first two mechanisms are strategy-proof, but in practice student assignment procedures impede students to submit a preference list that contains all their acceptable schools. Therefore, any desirable property of the mechanisms is likely toget distorted. We study the non trivial preference revelation game where students can only declare up to a fixed number (quota) of schools to be acceptable. We focus on the stability of the Nash equilibrium outcomes. Our main results identify rather stringent necessary and sufficient conditions on the priorities to guaranteestability. This stands in sharp contrast with the Boston Mechanism which yields stable Nash equilibrium outcomes, independently of the quota. Hence, the transition to any of the two mechanisms is likely to come with a higher risk that students seek legal actionas lower priority students may occupy more preferred schools.

Airline competition and network structure

This paper characterizes the equilibria in airline networks and their welfare implications in an unregulated environment. Competing airlines may adopt either fully-connected (FC) or hub-and-spoke (HS) network structures; and passengers exhibiting low brand loyalty to their preferred carrier choose an outside option to travel so that markets are partially served by airlines. In this context, carriers adopt hubbing strategies when costs are sufficiently low, and asymmetric equilibria where one carrier chooses a FC strategy and the other chooses a HS strategy may arise. Quite interestingly, flight frequency can become excessive under HS network configurations.

Processos participatius, governança ambiental i desenvolupament territorial sostenible

Estudio realizado a partir de una estancia en el Centro de Filosofia e Ciências Humanas de la Universidade Federal de Santa Catarina, Brasil, durant entre septiembre y noviembre del 2005. El intercambio con los grupos de trabajo del Programa de Pós-Graduçao Interdisciplinar em Ciências Humanas (UFSCE-Brasil), se ha llevado a cabo con el objetivo de profundizar en las diferentes perspectivas teóricas y analíticas que orientan la reflexión sobre el papel crítico de los investigadores en el área de sociología del conocimiento ambiental científico. Esto ha permitido conocer experiencias-laboratorios de procesos participativos para planear intervenciones en áreas protegidas. Estas orientaciones conceptuales, epistemológicas y metodológicas ayudaran a la candidata a reforzar la aproximación de investigación participativa del proyecto “Avaluació social multicriteri per a la presa de decisions orientades a una gestió conservativa de sistemes agropecuaris i el desenvolupament sostenible de la zona seca i semi-seca del paisatge terrestre protegit de Miraflor-Moropotente (Nicaragua)” que es la línea del trabajo de PhD de la candidata. En especial, las reflexiones teóricas y metodológicas se han centrado en los siguientes temas: aproximación sistemática y basada en los actores para el análisis de sistemas complejos y incertezas, métodos participativos para las evaluaciones integradas de sustentabilidad que apoyan los procesos de toma de decisiones, o el nuevo papel de los investigadores sobre una perspectiva compleja de análisis y diálogo entre los conocimientos científicos y locales.

Business-science research collaboration under moral hazard

I analyze, in the context of business and science research collaboration, how the characteristics of partnership agreements are the result of an optimal contract between partners. The final outcome depends on the structure governing the partnership, and on the informational problems towards the efforts involved. The positive effect that the effort of each party has on the success of the other party, makes collaboration a preferred solution. Divergence in research goals may, however, create conflicts between partners. This paper shows how two different structures of partnership governance (a centralized, and a decentralized ones) may optimally use the type of project to motivate the supply of non-contractible efforts. Decentralized structure, however, always choose a project closer to its own preferences. Incentives may also come from monetary transfers, either from partners sharing each other benefits, or from public funds. I derive conditions under which public interventio

Gestió forestal de masses d'arboç (Arbutus unedo) en regeneració després de foc al terme municipal d'Esparreguera

Els incendis forestals són una pertorbació amb un paper decisiu en l’estructura i dinàmica dels ecosistemes mediterranis. La majoria de les seves espècies vegetals presenten mecanismes de resposta al foc, com la germinació de llavors i la rebrotada d’individus cremats. Les masses forestals regenerades a partir de rebrots assoleixen densitats massa altes i una baixa producció, i, per tant, és fonamental dur a terme una gestió mitjançant tractaments silvícoles. El principal objectiu d’aquest projecte és quantificar l’efecte de la selecció de rebrots i la selecció de rebrots més la desbrossada sobre el creixement de l’Arbutus unedo. S’han estudiat 12 parcel—les en regeneració després dels incendis de 1985, 1986 i 1994 al terme municipal d’Esparreguera. Els resultats mostren que els dos tractaments afavoreixen de la mateixa manera el creixement dels peus d’Arbutus unedo, a causa de la disminució de la competència intraespecífica i interespecífica. La desbrossada (a nivell de parcel—la, no d’individu), no obstant, provoca un increment probablement perjudicial de l’alçada dels rebrots, per la major disponibilitat de llum. Per tal de proposar un model de gestió forestal, s’ha realitzat una anàlisi multicriterial dels diferents escenaris, on s’han considerat altres criteris, com són el model de combustible, la possibilitat de pastura i el cost econòmic. L’alternativa preferida en els boscos d’Arbutus unedo és la selecció de rebrots i la desbrossada.