Leontief versus Ghosh: two faces of the same coin

In this paper we explore the sectoral and aggregate implications of some endogeneization rules (i.e. on value-added and final demand) which have been common in the Leontief model and have been recently proposed in the Ghosh model. We detect that these rules may give rise in both models to some allegedly pathological behavior in the sense that sectoral or aggregate output, very often, may not follow the logical and economically expected direct relationship with some underlying endogenous variables—namely, output and value-added in the Ghosh model and output and consumption in the Leontief model. Because of the common mathematical structure, whatever is or seems to be pathological in the Ghosh model also has a symmetric counterpart in the Leontief model. These would not be good news for the inner consistency of these linear models. To avoid such possible inconsistencies, we propose new and simple endogeneization rules that have a sound economic interpretation.

Mean first-passage time for system driven by the coin-toss square wave

We study the mean-first-passage-time problem for systems driven by the coin-toss square-wave signal. Exact analytic solutions are obtained for the driftless case. We also obtain approximate solutions for the potential case. The mean-first-passage time exhibits discontinuities and a remarkable nonsmooth oscillatory behavior which, to our knowledge, has not been observed for other kinds of driving noise.

Using the optical mouse sensor as a two-euro counterfeit coin detector

In this paper, the sensor of an optical mouse is presented as a counterfeit coin detector applied to the two-Euro case. The detection process is based on the short distance image acquisition capabilities of the optical mouse sensor where partial images of the coin under analysis are compared with some partial reference coin images for matching. Results show that, using only the vision sense, the counterfeit acceptance and rejection rates are very similar to those of a trained user and better than those of an untrained user.

PANG 3D

El projecte consisteix en una versió 3D del famós joc Pang. El joc original va ser publicat per Mitchell, una companyia que ja no existeix, el 1989 en format COIN-OP1. Des de la seva data de publicació va representar un gran èxit de públic i de vendes per a la companyia, que en va treure algunes versions més.

España en Europa 1996-2004

Pensar globalmente, actuar localmente” es un slogan imprescindible en el discurso político de nuestros días. Pues bien, la práctica política, en materia de Unión Europea, de los dos gobiernos del Partido Popular, presididos por José María Aznar (1996-2004), nos permite acuñar un slogan de signo bien diferente: “pensar localmente, actuar en Europa”. En efecto, si algo caracteriza a estos ocho años de práctica política de José María Aznar es haber convertido sus preocupaciones domésticas en factor exclusivo de su estrategia europea, con independencia del contexto de cada momento y de la necesidad de encajar objetivos nacionales con objetivos europeos. De ahí que sea lógico que la campaña electoral que ha precedido a las elecciones generales del 14 de marzo no haya recogido ninguno de los temas que dominan en la agenda de la UE en el momento actual. Ni la ampliación, ni la Constitución, ni tampoco el proceso de conformación de un núcleo duro tienen cabida en el debate político españo

Spain in Europe 1996-2004

“Thinking globally, acting locally" is an essential slogan in the current political discourse. Yet, in view of the policies on the European Union carried out by the two governments of the People’s Party (PP) headed by José María Aznar between 1996 and 2004, we could coin a quite different slogan: "thinking locally, acting in Europe". Indeed, José María Aznar’s policy-making during the last eight years has been characterised by turning his domestic concerns into the ‘exclusive factor’ of his European strategy, regardless of the context and the need for fitting in national objectives with Europeans’. Hence, it was natural that the electoral campaign preceding the general elections held on Sunday, 14 March, did not deal with any of the topics prevailing in the EU’s current agenda. Neither enlargement nor the Constitution, nor the process of shaping a core group within the EU, seem to have room in Spain’s political debate...

Psychological pressure in competitive environments: Evidence from a randomized natural experiment

Much like cognitive abilities, emotional skills can have major effects on performance and economic outcomes. This paper studies the behavior of professionalsubjects involved in a dynamic competition in their own natural environment. Thesetting is a penalty shoot-out in soccer where two teams compete in a tournamentframework taking turns in a sequence of five penalty kicks each. As the kicking order is determined by the random outcome of a coin flip, the treatment and control groups are determined via explicit randomization. Therefore, absent any psychological effects, both teams should have the same probability of winning regardless of the kicking order. Yet, we find a systematic first-kicker advantage. Using data on 2,731 penalty kicks from 262 shoot-outs for a three decade period, we find that teams kicking first win the penalty shoot-out 60.5% of the time. A dynamic panel data analysis shows that the psychological mechanism underlying this result arises from the asymmetry in the partial score. As most kicks are scored, kicking first typically means having the opportunity to lead in the partial score, whereas kicking second typically means lagging in the score and having the opportunity to, at most, get even. Having a worse prospect than the opponent hinders subjects' performance.Further, we also find that professionals are self-aware of their own psychological effects. When a recent change in regulations gives winners of the coin toss the chance to choose the kicking order, they rationally react to it by systematically choosing to kick first. A survey of professional players reveals that when asked to explain why they prefer to kick first, they precisely identify the psychological mechanism for which we find empirical support in the data: they want to lead in the score inorder to put pressure on the opponent.

Mean first-passage times for systems driven by equilibrium persistent-periodic dichotomous noise

In a recent paper, [J. M. Porrà, J. Masoliver, and K. Lindenberg, Phys. Rev. E 48, 951 (1993)], we derived the equations for the mean first-passage time for systems driven by the coin-toss square wave, a particular type of dichotomous noisy signal, to reach either one of two boundaries. The coin-toss square wave, which we here call periodic-persistent dichotomous noise, is a random signal that can only change its value at specified time points, where it changes its value with probability q or retains its previous value with probability p=1-q. These time points occur periodically at time intervals t. Here we consider the stationary version of this signal, that is, equilibrium periodic-persistent noise. We show that the mean first-passage time for systems driven by this stationary noise does not show either the discontinuities or the oscillations found in the case of nonstationary noise. We also discuss the existence of discontinuities in the mean first-passage time for random one-dimensional stochastic maps.

The Price of luck

We find that the vast majority of students taking an advanced undergraduate finance course show a preference for luck in a classroom experiment. In Phase I of the experiment part of the students, group A, were asked to guess a coin toss five times in a row. In Phase II the rest of the students, group B, were given 10 EUR to bet on some of the Group A students taking a second go at guessing a sequence of five coin tosses (Phase III). Group B students’ bets were by default allocated to the worse performing student in Phase I. Switching to better performing Group A students was costly. A total of 23 out of 28 students were willing to pay for switching and thus showed a preference for luck.

La crisis del segle III a l’àrea compresa entre Tarraco i Saguntum: aproximació a partir de les dades arqueològiques

The purpose of this work is to evaluate the possible impact of the so-called “crisis of the 3rd century” in the area between Tarraco (Tarragona) and Saguntum (Sagunt), currently corresponding to the southern limit of Catalonia and the north of Valencia, which during the Roman era made up the southernmost part of the conventus Tarraconensis. The processes of change experienced in rural settlements and cities between the Severan dynasty and the beginning of the tetrarchy are analyzed, and the importance of the city-country relationship is examined to explain these changes. The extent of the Frankish invasion during of the Gallic period, initially substantiated by sources and now by archaeological evidence, is discussed. The study of coin hoards (treasures and deposits) from the second half of the 3rd century, found in abundance in this area, is a very interesting aspect of this topic. In addition, a quantitative approach is used to study the population changes experienced as a result of the rural settlement of this area during the 3rd century, between the High and the Low Empires.

Estudi de la mineria de bitcoins

El bitcoin és una moneda virtual descentralitzada que es basa en la criptografia per al seu correcte funcionament. S’utilitza la criptografia en diversos processos de la moneda: creació de comptes, validació de transaccions, generació de moneda, etc. La mineria és el procés mitjançant el qual les transaccions són validades i a la vegada també és el procés amb el qual es genera nova moneda. Aquest projecte està centrat en l’anàlisi d’aquest procés.