When does universal peace prevail? Secession and group formation in rent seeking contests and policy conflicts

This paper analyzes secession and group formation in a general model of contest inspired by Esteban and Ray (1999). This model encompasses as special cases rent seeking contests and policy conflicts, where agents lobby over the choice of a policy in a one-dimensional policy space. We show that in both models the grand coalition is the efficient coalition structure and agents are always better off in the grand coalition than in a symmetric coalition structure. Individual agents (in the rent seeking contest) and extremists (in the policy conflict) only have an incentive to secede when they anticipate that their secession will not be followed by additional secessions. Incentives to secede are lower when agents cooperate inside groups. The grand coalition emerges as the unique subgame perfect equilibrium outcome of a sequential game of coalition formation in rent seeking contests.

All-pay auction equilibria in contests

We analyze (non-deterministic) contests with anonymous contest success functions. There is no restriction on the number of contestants or on their valuations for the prize. We provide intuitive and easily verifiable conditions for the existence of an equilibrium with properties similar to the one of the (deterministic) all-pay auction. Since these conditions are fulfilled for a wide array of situations, the predictions of this equilibrium are very robust to the specific details of the contest. An application of this result contributes to fill a gap in the analysis of the popular Tullock rent- seeking game because it characterizes properties of an equilibrium for increasing returns to scale larger than two, for any number of contestants and in contests with or without a common value. Keywords: (non-) deterministic contest, all-pay auction, contest success functions. JEL Classification Numbers: C72 (Noncooperative Games), D72 (Economic Models of Political Processes: Rent-Seeking, Elections), D44 (Auctions).

Welfare Maximizing Contest Success Functions when the Planner Cannot Commit

We analyze how a contest organizer chooses optimally the winner when the contestants' efforts are already exerted and commitment to the use of a given contest success function is not possible. We de…ne the notion of rationalizability in mixed-strategies to capture such a situation. Our approach allows to derive different contest success functions depending on the aims and attitudes of the decider. We derive contest success functions which are closely related to commonly used functions providing new support for them. By taking into account social welfare considerations our approach bridges the contest literature and the recent literature on political economy. Keywords: Endogenous Contests, Contest Success Function, Mixed-Strategies. JEL Classi…cation: C72 (Noncooperative Games), D72 (Economic Models of Political Processes: Rent-Seeking, Elections), D74 (Conflict; Conflict Resolution; Alliances)

Signaling in Dynamic Contests: Some Impossibility Results

General signaling results in dynamic Tullock contests have been missing for long. The reason is the tractability of the problems. In this paper, an uninformed contestant with valuation vx competes against an informed opponent with valuation, either high vh or low vl. We show that; (i) When the hierarchy of valuations is vh ≥ vx ≥ vl, there is no pooling. Sandbagging is too costly for the high type. (ii) When the order of valuations is vx ≥ vh ≥ vl, there is no separation if vh and vl are close. Sandbagging is cheap due to the proximity of valuations. However, if vh and vx are close, there is no pooling. First period cost of pooling is high. (iii) For valuations satisfying vh ≥ vl ≥ vx, there is no separation if vh and vl are close. Bluffing in the first period is cheap for the low valuation type. Conversely, if vx and vl are close there is no pooling. Bluffing in the first stage is too costly. JEL: C72, C73, D44, D82. KEYWORDS: Signaling, Dynamic Contests, Non-existence, Sandbag Pooling, Bluff Pooling, Separating

The distribution of talent across contests

Do the contests with the largest prizes attract the most able contestants? Towhat extent do contestants avoid competition? In this paper, we show, theoreticallyand empirically, that the distribution of abilities plays a crucial role in determiningcontest choice. Sorting exists only when the proportion of high-ability contestantsis sufficiently small. As this proportion increases, contestants shy away from competitionand sorting decreases, such that, reverse sorting becomes a possibility. Wetest our theoretical predictions using a large panel data set containing contest choiceover three decades. We use exogenous variation in the participation of highly-ablecompetitors to provide empirical evidence for the relationship among prizes, competition,and sorting.

Competition amongst contests

This article analyses the allocation of prizes in contests. While existing models consider a single contest with an exogenously given set of players, in our model several contests compete for participants. As a consequence, prizes not only induce incentive effects but also participation effects. We show that contests that aim to maximize players aggregate effort will award their entire prize budget to the winner. In contrast, multiple prizes will be awarded in contests that aim to maximize participation and the share of the prize budget awarded to the winner increases in the contests randomness. We also provide empirical evidence for this relationship using data from professional road running. In addition, we show that prize structures might be used to screen between players of differing ability.

Diradicals acting through diamagnetic phenylene vinylene bridges: Raman spectroscopy as a probe to characterize spin delocalization

We present a complete Raman spectroscopic study in two structurally well-defined diradical species of different lengths incorporating oligo p-phenylene vinylene bridges between two polychlorinated triphenylmethyl radical units, a disposition that allows sizeable conjugation between the two radicals through and with the bridge. The spectroscopic data are interpreted and supported by quantum chemical calculations. We focus the attention on the Raman frequency changes, interpretable in terms of: (i) bridge length (conjugation length); (ii) bridge conformational structure; and (iii) electronic coupling between the terminal radical units with the bridge and through the bridge, which could delineate through-bond spin polarization, or spin delocalization. These items are addressed by using the"oligomer approach" in conjunction with pressure and temperature dependent Raman spectroscopic data. In summary, we have attempted to translate the well-known strategy to study the electron (charge) structure of π−conjugated molecules by Raman spectroscopy to the case of electron (spin) interactions via the spin delocalization mechanism.

Foundations for contest success functions

In the literature the outcome of contests is either interpreted as win probabilities or as shares of the prize. With this in mind, we examine two approaches to contest success functions. In the first we analyze the implications of contestants' incomplete information concerning the "type" of the contest administrator. While in the case of two contestants this approach can rationalize prominent contest success functions, we show that it runs into difficulties when there are more agents. Our second approach interprets contest success functions as sharing rules and establishes a connection to bargaining and claims problems which is independent of the number of contestants. Both approaches provide foundations for popular contest success functions and guidelines for the definition of new ones. Keywords: Endogenous Contests, Contest Success Function. JEL Classification: C72 (Noncooperative Games), D72 (Economic Models of Political Processes: Rent-Seeking, Elections), D74 (Conflict; Conflict Resolution; Alliances).

Instrumentació i control d'actuadors fluídics per a sistemes analítics: sistema de regulació d'una microbomba de precisió a mode de xeringa

En aquest projecte s’ha implementat un sistema de control per a les bombes microfluídiques LPVX de The Lee Company funcionant a mode de xeringa. El sistema consisteix en un circuit controlador basat en el microxip UDN 296 B de Allegro MicroSystems, que conté dos Ponts en H per a controlar motors pas a pas i dos mòduls de Modulació d’Amplada de Polsos (PWM), governat a partir d’un programa de control com a instrument virtual dissenyat sota l’entorn LabVIEW. El programa de control permet indicar la quantitat de volum a aspirar o dispensar per la bomba i escollir entre una execució simple o una de continuada, podent-ne controlar en aquest segona opció el temps entre execució i execució. El programa també permet visualitzar el procés mitjançant la obtenció de la imatge d’una webcam amb DirectShow. Finalment també permet el control remot de l’Instrument Virtual a través de la xarxa d’Internet.

Respuesta no lineal y criterios de diseño de puentes arco espaciales

El desarrollo más reciente de los puentes arco ha llevado a una nueva tipología: los “puentes arco espaciales”. Se entiende por puente arco espacial todo puente arco en el que, por su configuración geométrica y estructural, las cargas gravitatorias generan esfuerzos no contenidos en el plano del arco. Por un lado, aparecen para satisfacer las necesidades funcionales cuando estructuras en arco resultan las más adecuadas para sostener tableros curvos y evitar así apoyos intermedios. Desde un punto de vista estético, surgen como demanda de los nuevos puentes en entornos urbanos, buscando, no sólo una forma cuidada, sino persiguiendo convertirse en emblemas de la ciudad a partir de la originalidad y la innovación. Su proyecto y construcción es posible gracias a las grandes posibilidades que ofrecen los nuevos métodos de cálculo y dibujo por ordenador, en los que, a través del incremento de memoria y rapidez, cada vez se emplean programas más completos y nuevas modelizaciones, más cercanas a la realidad. No menos importante es el desarrollo de los medios auxiliares de construcción y de las herramientas de CAD/CAM, que convierte en construibles por control numérico formas de manufactura impensables. Ello trasciende en infinitas posibilidades de diseño y estructura. Sin embargo, el diseño y construcción de estas nuevas tipologías no ha estado acompañado por el avance en el estado del conocimiento fundamentado en la investigación, ya que se han desarrollado pocos estudios que explican parcialmente la respuesta estructural de estos puentes. Existe, por lo tanto, la necesidad de profundizar en el estado del conocimiento y clarificar su respuesta estructural, así como de plantear, finalmente, criterios de diseño que sirvan de apoyo en las fases de concepción y de proyecto a estas nuevas tipologías.

Scepticism Revisited

Liberalism claims that for a subject S to be justified in believing p, a proposition about the external world, on the basis of his senses it is not necessary to be antecedently justified in believing propositions as there is an external world. On the other hand, conservatism claims that to be justified in believing that p on the basis of one’s perception, one must have antecedent justification to believe that p. Intuitively, we are inclined to think that liberalism about the structure of perceptual justification fits better with our epistemic practices. We acknowledge that, although we cannot produce warrant for the background belief in the external world, our empirical beliefs can be perceptually justified. However, I am interested in arguing that conservatism is theoretically better supported than liberalism. The first reason to defend this is based on the fact that in embracing liberalism dogmatism is affected by pervasive problems. The second one comes from recognizing the strength of the argument based on the thesis that experience is theory-laden. But not all are advantages for conservatism. Conservatism is presupposed in contemporary formulations of scepticism through the requirement of prior justification for background assumptions, and this fact compels anti-sceptical conservatives to conceive a non-evidential form of warrant, entitlement, to contest the sceptical threat My main worry is that, although the path of entitlement has some prospects to succeed, this new notion of justification seems to be posed ad hoc for conservatives to solve the sceptical problem. These contents are organized along the three chapters. The result of chapter 1 is a pattern of sceptical argument formed by two premises: P1*, a conservative principle, and P2*. In chapter 2 and chapter 3 two anti-sceptical proposals against the argument sketched in chapter 1 are described. Chapter 2 is devoted to explain and assess a first anti-sceptical proposal that denies P1*: dogmatism. Moreover, in chapter 3, another anti-sceptical strategy is described (the route of entitlement) that contests scepticism denying the plausibility of P2*.

XVI Olimpíada Nacional de Química 2002-2003

Article que es refereix a la XVI Olimpíada Nacional de Química (2002 – 2003), celebrada el 9-12 de maig de 2003, al Seminari Menor de Tarazona (Saragossa). L’ olimpíada consisteix en dues proves: la primera consisteix en la resolució de 4 problemes llargs, i la segona en 45 preguntes de resposta múltiple (tipus test) que contenen qüestions teòriques i problemes curt. En aquest article s’ esmenten els alumnes que han obtingut alguna mena de distinció, els classificats per a la Fase Nacional, els problemes proposats i les característiques de les preguntes del test

XVIII Olimpíada Nacional de Química 2004-2005

Article que es refereix a la XVIII Olimpíada Nacional de Química (2004 – 2005), celebrada el 15-18 d' abril de 2005, al Luarca(Astúries). L’ olimpíada consisteix en dues proves: la primera consisteix en la resolució de 4 problemes llargs, i la segona en 45 preguntes de resposta múltiple (tipus test) que contenen qüestions teòriques i problemes curts. En aquest article s’ esmenten els alumnes que han obtingut algun tipus de distinció, els classificats per a la Fase Nacional, els problemes proposats i les característiques de les preguntes del test

Decentralized model reference control of flexible cable-stayed beam structures

A decentralized model reference controller is designed to reduce the magnitude of the transversal vibration of a flexible cable-stayed beam structure induced by a seismic excitation. The controller design is made based on the principle of sliding mode such that a priori knowledge

Els marges del pensament polític contemporani

La crisi i esfondrament del pensament metafísic heretat de la modernitat deixa la filosofia contemporània davant d'un nou paradigma on el coneixement s’ha de construir prescindint de tota identitat i fonamentació. El meu projecte s’estableix com un recorregut descendent que parteix d’un àmbit concret, com és el del problema de la manca de fonamentació en la filosofia política contemporània, per arribar a la veritable arrel del problema general que no és altre que la mateixa naturalesa del llenguatge filosòfic. El punt de partida és la pregunta sobre la possibilitat d’una filosofia política en termes postmetafísics. La filosofia política, atrapada entre les forces de la tirania unitària del concepte metafísic i la dissolució pràctica en pro de la realitat instrumental, traça ponts cap a l’estètica i la deconstrucció, que tenen com a corol•lari final qüestionar-nos els propis límits del pensament polític. El concepte d’impolític és una sortida deconstructiva a aquest atzucac. Des d’Esposito, Rancière, Nancy, però sobretot Massimo Cacciari, he aprofundit en el paradigma postmetafísic que origina aquesta negació política de la pròpia política, política com els seus límits, relació com a distància i identitat com a silenci. És evident que la clau de volta és l’herència i recepció contemporània de Nietzsche i la seva crítica a la transcendentalitat moderna en el sí de l’elaboració d’un coneixement en un naufragi constant pel fracàs de la síntesi que anhela. És aquesta herència la que ha possibilitat aquest pensament negatiu contemporani, el del joc wittgensteinià, la deconstrucció del valor que queda convertit en el seu propi marge (Derrida). Definim així no només una comunitat política basada en la incommensurabilitat dels seus membres alhora buits de contingut (Musil), sinó un model de llenguatge que és el seu propi silenci, un llenguatge en contínua lluita contra sí mateix. El meu projecte és una relectura d’aquesta veritat no identitària on el concepte de diàleg pren una importància cabdal. La filosofia de la música aquí es presenta com un terreny fèrtil d’eines conceptuals a l’hora de desenvolupar-ho. La música és el llenguatge negatiu que només troba possibilitat en la seva pròpia impossibilitat de contingut sintètic. Més enllà de les referències obligatòries a chönberg i Adorno entre altres, el camí iniciat per Bergson amb la introducció de la temporalitat a la discussió obra la porta al paper de l’esdveniment en aquest discurs sobre la impossibilitat. Tornant a la filosofia, on el propi llenguatge filosòfic es defineix ja com a impossible, l’esdeveniment reobre l’antiga tensió entre l’escriptura i la paraula viva, veritable fonament del problema, i vèrtex de la possibilitat d’aquesta filosofia impossible.