O principio de Hamilton

Grao en FísicaA materia Mecánica Clásica II forma parte do bloque que no Grao en Física se dedica á Mecánica Clásica, que é a parte da Física que estuda o movemento das partículas e os corpos materiais e que comprende a teoría iniciada por Galileo e Newton e desenvolvida nos séculos XVIII e XIX por Lagrange e Hamilton, incluíndo tamén a Relatividade Especial de Einstein. A materia divídese en catro bloques temáticos de similar peso e duración temporal. O primeiro deles ten un marcado carácter teórico e trata de introducir as ecuacións da Mecánica a partir do principio integral formulado por Hamilton en 1815. O alumno xa coñece ditas ecuacións, tanto na formulación de Newton como naquela de Lagrange, que se introduciu na materia do primeiro semestre a partir dun principio diferencial (o principio de d’Alembert). O interese desta nova formulación reside na súa potencia e posibilidade de extensión a outras ramas da Física, ata o punto de poder ser considerada como un principio fundamental. Para entender este principio hai que introducir as técnicas matemáticas do cálculo variacional para deducir as ecuacións de Lagrange e o método dos multiplicadores para sistemas con ligaduras. As ecuacións canónicas introdúcense a nivel básico para rematar coa súa expresión en termos de corchetes de Poisson e deixar sentadas as bases máis elementais para a transición cara a Mecánica Cuántica. Esta unidade didáctica ten una importante carga teórica e conceptual. Moitas das ideas que se introducen nela terán un papel fundamental non só no resto da materia senón tamén en outras materias da titulación e en moitos dos desenvolvementos da Física actual.Universidade de Santiago de Compostela. Servizo de Normalización Lingüístic

Seigniorage and Inflation Tax in Romania: What Is the Executive Giving up by Adopting the Euro?

[Abstract] This paper is concerned with measuring the seigniorage in Romania since the fall of communism and the potential gains after passing to euro. Starting from the balance sheet of the central bank, we estimated these levels of seigniorage for a period of 27 years. Our findings suggest that this source of revenue was at very high rates in the period of the 90’s, mostly due to the huge prolonged inflation rates. Ever since the independence of the central bank, these levels of seigniorage dropped and became constant, at around 1-2% of the GDP. Also, we computed the potential gains due to euro adoption. We showed that as Romania converge with the rest of the Eurozone its seigniorage potential gains from euro adoption drops. Because these gains are only very small in relation to national income, we argue that the implications of giving up own currency are not budget related

Social Ties, Network Socioeconomic Diversity and Sporting Event Attendance

[Abstrac] Heterogeneous social networks are the source of valued life outcomes, and this heterogeneity is associated with different circumstances and personal attributes. This paper analyses the size and socioeconomic diversity of social networks of people who attend sporting events. The relationship between sports participation and social networks has been widely analysed. However, the role of attending sporting events in the creation of different forms of social capital, specifically networks’ socioeconomic heterogeneity, remains unclear. A better understanding of this issue may help to clarify the social impact of sports participation. Drawing on a unique dataset collected through the administration of a questionnaire to a representative sample of the Spanish population and employing an ad hoc, class-based position generator, we show that attendance to sporting events is associated with social mixing and the creation of networks of people from different occupational classes. Indeed, the size of these effects increases with the frequency of attendance. These results suggest that attending sporting events is associated with bridging social capital and may foster social integration and life opportunities for those who are less advantaged

La dotación de capital social como factor determinante de la corrupción

El objetivo del presente trabajo es abordar el papel que desempeñan los entramados sociales como factor explicativo de la corrupción. En particular, se trata de determinar en qué medida los niveles de corrupción percibidos a escala nacional están asociados a ciertas formas de confianza y normas sociales y, por tanto, a las dotaciones de las diversas expresiones de capital social. La evidencia empírica obtenida sugiere que la confianza generalizada y las normas universalitas constituyen un capital social positivo que está inversamente relacionado con los niveles de corrupción. Por el contrario, las variantes particularistas de la confianza representan un capital social negativo que está directamente vinculado a la generación de relaciones de corrupción.________________________________The objective of the present work is to address the role played by social capital as an explanatory factor of corruption. In particular, we attempt to estimate to what extent the perceived levels of corruption are associated to certain forms of trust and social norms and, therefore, to social capital in its diverse expressions. The empirical evidence suggests that generalized trust and universalistic norms constitute a positive form of social capital that is inversely related to corruption. By contrast, the particularistic expressions of trust represent a negative social capital directly linked to the rising of corruption relationships

Government responsiveness in times of internal devaluation : hints at a crisis of representation in Eurozone

[Abstract] The research objective of this paper is to find out the best predictor of internal devaluation measures imposed by governmental decision. There are two competing hypotheses. On the one hand, political instability may affect the implementation of internal devaluation due to opportunistic behavior and strategic thinking from the parties in power. On the other hand, governments also respond in real time to the signals from the financial markets with respect to the necessity of such measures. To accommodate for the contrasting hypotheses, we employ a panel dataset (2007-2017 Eurozone countries) with a fixed-effects model where the expected time in office of each cabinet (previously estimated using survival analysis) and the bond yields paid to issue public debt into financial markets, are explanatory variables. After controlling for other effects, the results show that expected time has no significant effect, while the yields do, something that might hint at a crisis of representation.[Resumen] El objetivo de este artículo es encontrar el mejor predictor de las medidas de devaluación interna implementadas por los gobiernos de los países de la eurozona. Con esta finalidad se someten a contraste dos hipótesis explicativas alternativas. Por un lado, la inestabilidad política puede afectar la implementación de la devaluación interna debido al comportamiento oportunista y al pensamiento estratégico de los partidos en el poder. Por el otro lado, los gobiernos responden en tiempo real a las señales que emiten los mercados financieros sobre la necesidad de adoptar tales medidas. Para poder probar empíricamente ambas hipótesis, se emplea un conjunto de datos de panel (países de la Eurozona 2007-2017) y se estima un modelo de efectos fijos donde el tiempo esperado en el cargo de cada gobierno (previamente estimado mediante análisis de supervivencia) y los rendimientos de los bonos públicos en los mercados financieros son variables explicativas. Después de controlar por otros efectos, los resultados muestran que el tiempo que un gobierno espera mantenerse en el poder no tienen un efecto significativo, mientras que los rendimientos de la deuda pública sí lo tienen, lo que podría indicar una crisis de representación

Decentralization and expected time in office. The effect of decentralization on cabinet durability

[Abstract]: The objective of this study is to analyze the role played by both fiscal and political decentralization as determinants of the expected time in office, understood as the latent (unobservable) durability of the cabinets. Using data for all the EU member states for the period that spans from 2007 up to 2017 and employing two competing survival analysis models, namely Weibull (parametric) and Cox (semiparametric), the results show that, even after controlling for other relevant variables (such as majority in legislative, the number of parties in government, the range between the most distant positions in coalition, etc.), decentralization (either fiscal or political) seem to be insignificant over the expected time in office of the cabinets. To the best of our knowledge there is only one study that focused on testing this kind of relationships, but which only considered the case of regional parties with portfolio positions (thus losing sight of the very important “supply and confidence agreements”). The originality of this works stems from the fact that we are more inclusive and that we employ new data and new variables that are more appropriate for framework of European politics, dominated by the anti-EU and populist debates, since the Great Recession of 2008

Identificación, empatía y disposición de pago

The present study analyzes the effects of sympathy and identification between sports fans and clubs in the recognition of willingness to pay in favor of these organizations. With this objective, after reconsidering the diverse approaches to this type of bonds, we propose in the first part a theoretical model that considers the psychosociological factors which affect the willingness to pay for this kind of goods and services that have characteristics similar to public goods. This model allows us to extract two hypotheses on the interrelation between sympathy, income and willingness to pay. In the second part, we put these hypotheses to the test. The results establish, as predicted, that identification or sympathy with a club constitutes an important causal factor in its valuation, although income has no causal relation with this. Both can explain some irregularities found within the contingent valuation methodEl presente estudio analiza el impacto de la simpatía y la identificación entre seguidores y clubes deportivos sobre el reconocimiento de la disposición a pagar en favor de estas organizaciones. Para ello, después de reconsiderar los distintos acercamientos a este tipo de vínculos, en la primera parte proponemos un modelo teórico que considera los factores psicosociales que influyen en la disposición a pagar por este tipo de bienes y servicios, que tienen unas características similares a los bienes públicos. Este modelo nos permite elaborar dos hipótesis sobre la interrelación entre la empatía, los ingresos y la disposición a pagar. En la segunda parte ponemos a prueba estas hipótesis. Tal y como esperábamos, los resultados indican que la identificación o simpatía con un club constituye un importante factor causal en su valoración, mientras que esta relación no existe con la variable ingresos. Ambos factores sirven para explicar las anomalías encontradas en el método de valoración contingenteThe authors acknowledge financial support by 10SEC100041 PR from the Xunta de Galici

Felicidad, bienestar subjetivo y satisfacción en la sociedad gallega

Estudio sobre la evolución de los indicadores de bienestar subjetivo (felicidad) en la sociedad gallega y sus determinante

National vs. European mandate: a rational choice model of interest rate decisions by the European Central Bank

Paper prepared for the 33rd annual conference and 8th research conference of UACES, Newcastle, 2-4 September 2003.The aim of this paper is to investigate to what extent the members of the Governing Council of the European Central Bank (ECB) act as if they had a national mandate, instead of acting in the interests of price stability in the euro area as a whole. The paper develops a simple rational choice model of interest rate decisions inside the Governing Council of the ECB based on national mandates, and tests it against a model based on a European mandate, using monthly data from January 1999 to July 2003. The paper concludes that the model assuming national mandates explains the data better, and derives some implications for the reform of the ECB and other pseudo-independent institutions such as the European Commission, especially in the eve of the next enlargement