36 resultados para Ray theoretical Model
em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain
Resumo:
Unilateral migration policies impose externalities on other countries. In order to try to internalize these externalities, countries sign bilateral migration agreements. One element of these agreements is the emphasis on enforcing migration policies: immigrant-receiving countries agree to allow more immigrants from their emigrant-sending partner if they cooperate in enforcing their migration policy at the border. I present a simple theoretical model that justifies this behavior in a two-country setting with welfare maximizing governments. These governments establish migration quotas that need to be enforced at a cost. I prove that uncoordinated migration policies are inefficient. Both countries can improve welfare by exchanging a more "generous" migration quota for expenditure on enforcement policy. Contrary to what could be expected, this result does not depend on the enforcement technology that both countries employ.
Resumo:
This paper examines the impact of ethnic divisions on conflict. The analysis relies on a theoretical model of conflict (Esteban and Ray, 2010) in which equilibrium conflict is shown to be accurately described by a linear function of just three distributional indices of ethnic diversity: the Gini coefficient, the Hirschman-Herfindahl fractionalization index, and a measure of polarization. Based on a dataset constructed by James Fearon and data from Ethnologue on ethno-linguistic groups and the "linguistic distances" between them, we compute the three distribution indices. Our results show that ethnic polarization is a highly significant correlate of conflict. Fractionalization is also significant in some of the statistical exercises, but the Gini coefficient never is. In particular, inter-group distances computed from language and embodied in polarization measures turn out to be extremely important correlates of ethnic conflict.
Resumo:
The paper investigates the role of mothers in affecting childrens' performance at school. It develops a theoretical model in which household is treated as an individual, whose utility depends on the performance at school of the student and on consumption. The model focuses on the possibilities through which mother’s help may affect pupil's performance in terms of time devoted to supervision and spillover effects. Empirical evidence, using Italian PISA 2006, shows that highly educated mothers have a positive impact on students' score only when they are highly qualified in the job market.
Resumo:
The growing multilingual trend in movie production comes with a challenge for dubbing translators since they are increasingly confronted with more than one source language. The main purpose of this master’s thesis is to provide a case study on how these third languages (see CORRIUS and ZABALBEASCOA 2011) are rendered. Another aim is to put a particular focus on their textual and narrative functions and detect possible shifts that might occur in translations. By applying a theoretical model for translation analysis (CORRIUS and ZABALBEASCOA 2011), this study describes how third languages are rendered in the German, Spanish, and Italian dubbed versions of the 2009 Tarantino movie Inglourious Basterds. A broad range of solution-types are thereby revealed and prevalent restrictions of the translation process identified. The target texts are brought in context with some sociohistorical aspects of dubbing in order to detect prevalent norms of the respective cultures andto discuss the acceptability of translations (TOURY 1995). The translatability potential of even highly complex multilingual audiovisual texts is demonstrated in this study. Moreover, proposals for further studies in multilingual audiovisual translation are outlined and the potential for future investigations in this field thereby emphasised.
Resumo:
Multiple Sclerosis is the most common non-traumatic cause of neurologicaldisability in young people. There is no cure yet, and until recently, few long-termtherapies existed. Interferon beta (IFNβ) was the first treatment, and remains the mostcommonly prescribed. One of the most significant problems of IFNβ therapy is theproduction of drug specific antibodies. Up to 45% of patients develop neutralizingantibodies (NAbs) to IFNβ products. The neutralizing antibody binds to the biologicalagent preventing its interaction with its receptor, inhibiting the biological action of theprotein, which abrogates the clinical efficacy of IFNβ treatment. Interferon-betamediates its response by binding to its high affinity cell surface receptor and initiatingthe JAK/STAT signalling cascade. In this project we have analyzed the IFNβ signalingpathway in macrophages when neutralizing antibodies are present. The response tothis pathway after IFNβ stimulation shows a transient oscillatory rhythm of STAT1phosphorylation, which varies as NAbs concentration increases. To improve ourunderstanding of that behavior, we extended an existing mathematical model based onnonlinear ordinary differential equations of JAK/STAT pathway by including IFN-NAbassociation and IFN-activation receptor. Combining our theoretical model withexperimental data we could study the role of neutralizing antibodies on the molecularresponse and determine its lifetime after cytokine stimulation.
Resumo:
The purpose of this paper is to study the determinants of equilibrium in the market for daily funds. We use the EONIA panel database which includes daily information on the lending rates applied by contributing commercial banks. The data clearly shows an increase in both the time series volatility and the cross section dispersion of rates towards the end of the reserve maintenance period. These increases are highly correlated. With respect to quantities, we find that the volume of trade as well as the use of the standing facilities are also larger at the end of the maintenance period. Our theoretical model shows how the operational framework of monetary policy causes a reduction in the elasticity of the supply of funds by banks throughout the reserve maintenance period. This reduction in the elasticity together with market segmentation and heterogeneity are able to generate distributions for the interest rates and quantities traded with the same properties as in the data.
Resumo:
This paper presents evidence that the existence of deposit and lending facilities combined with an averaging provision for the reserve requirement are powerful tools to stabilize the overnight rate. We reach this conclusion by comparing the behavior of this rate in Germany before and after the start of the EMU. The analysis of the German experience is useful because it allows to isolate the effects on the overnight rate of these particular instruments of monetary policy. To show that this outcome is a general conclusion and not a particular result of the German market, we develop a theoretical model of reserve management which is able to reproduce our empirical findings.
Resumo:
We study the process by which subordinated regions of a country can obtain a more favourable political status. In our theoretical model a dominant and a dominated region first interact through a voting process that can lead to different degrees of autonomy. If this process fails then both regions engage in a costly political conflict which can only lead to the maintenance of the initial subordination of the region in question or to its complete independence. In the subgame-perfect equilibrium the voting process always leads to an intermediate arrangement acceptable for both parts. Hence, the costly political struggle never occurs. In contrast, in our experiments we observe a large amount of fighting involving high material losses, even in a case in which the possibilities for an arrangement without conflict are very salient. In our experimental environment intermediate solutions are feasible and stable, but purely emotional elements prevent them from being reached.
Resumo:
We propose a theoretical model to explain empirical regularities related to the curse of natural resources. This is an explicitly political model which emphasizes the behavior and incentives of politicians. We extend the standard voting model to give voters political control beyond the elections. This gives rise to a new restriction into our political economy model: policies should not give rise to a revolution. Our model clarifies when resource discoveries might lead to revolutions, namely, in countries with weak institutions. Natural resources may be bad for democracy by harming political turnover. Our model also suggests a non-linear dependence of human capital on natural resources. For low levels of democracy human capital depends negatively on natural resources, while for high levels of democracy the dependence is reversed. This theoretical finding is corroborated in both cross section and panel data regressions.
Resumo:
This paper analyzes both theoretically and empirically the relationship between distance and frequency of scheduled transportation services. We study the interaction between a monopoly firm providing high-speed scheduled service and personal trans- portation (i.e., car). Most interestingly, the carrier chooses to increase frequency of service on longer routes when competing with personal transportation because provid- ing a higher frequency (at extra cost) it can also charge higher fares that can boost its profits. However, when driving is not a relevant option, frequency of service de- creases for longer flights consistently with prior studies. An empirical application of our analysis to the European airline industry con?rms the predictions of our theoretical model.
Resumo:
El projecte exposat té com a propòsit definir i implementar un model de simulació basat en la coordinació i assignació dels serveis d’emergència en accidents de trànsit. La definició del model s’ha realitzat amb l’ús de les Xarxes de Petri Acolorides i la implementació amb el software Rockwell Arena 7.0. El modelatge de la primera simulació ens mostra un model teòric basat en cues mentre que el segon, mostra un model més complet i real gràcies a la connexió mitjançant la plataforma Corba a una base de dades amb informació geogràfica de les flotes i de les rutes. Com a resultat de l’estudi i amb l’ajuda de GoogleEarth, podem realitzar simulacions gràfiques per veure els accidents generats, les flotes dels serveis i el moviment dels vehicles des de les bases fins als accidents.
Resumo:
This paper presents a theoretical and empirical analysis of the relationship be- tween frequency of scheduled transportation services and their substitutability with personal transportation (using distance as a proxy). We study the interaction between a monopoly firm providing a high-speed scheduled service and private transportation (i.e., car). Interestingly, the carrier chooses to increase the frequency of service on longer routes when competing with personal transportation because by providing higher frequency (at extra cost) it can also charge higher fares which can boost its profits. However, in line with the results of earlier studies, frequency decreases for longer flights when driving is not a viable option. An empirical application of our analysis to the European airline industry confirms the predictions of our theoretical model. Keywords: short-haul routes; long-haul routes; flight frequency; distance JEL Classification Numbers: L13; L2; L93
Resumo:
This article provides a theoretical and empirical analysis of a firm's optimal R&D strategy choice. In this paper a firm's R&D strategy is assumed to be endogenous and allowed to depend on both internal firms. characteristics and external factors. Firms choose between two strategies, either they engage in R&D or abstain from own R&D and imitate the outcomes of innovators. In the theoretical model this yields three types of equilibria in which either all firms innovate, some firms innovate and others imitate, or no firm innovates. Firms'equilibrium strategies crucially depend on external factors. We find that the efficiency of intellectual property rights protection positively affects firms'incentives to engage in R&D, while competitive pressure has a negative effect. In addition, smaller firms are found to be more likely to become imitators when the product is homogeneous and the level of spillovers is high. These results are supported by empirical evidence for German .rms from manufacturing and services sectors. Regarding social welfare our results indicate that strengthening intellectual property protection can have an ambiguous effect. In markets characterized by a high rate of innovation a reduction of intellectual property rights protection can discourage innovative performance substantially. However, a reduction of patent protection can also increase social welfare because it may induce imitation. This indicates that policy issues such as the optimal length and breadth of patent protection cannot be resolved without taking into account specific market and firm characteristics. Journal of Economic Literature Classification Numbers: C35, D43, L13, L22, O31. Keywords: Innovation; imitation; spillovers; product differentiation; market competition; intellectual property rights protection.
Resumo:
L'àmbit d'aquest treball de final de carrera és el camp del disseny de les bases de dades relacionals, per la qual cosa aquest treball s'ha enfocat des de diversos punts de vista: a) Acadèmic. Es descriurà la teoria del disseny de bases de dades relacionals. b) Pràctic. Es posarà en pràctica tot el model teòric desenvolupant un cas concret (producte) que s'anirà intercalant amb el desenvolupament teòric del punt anterior. c) Tecnològic. El desplegament del producte es farà a l'SGBD Oracle 9i (s'hi porta a terme una introducció), on s'implementarà tota la interfície a la BD amb la tecnologia PL/SQL d'Oracle.
Resumo:
La calidad de vida relacionada con la salud se ha descrito como un concepto multidimensional que incluye la identificación de síntomas, el estado funcional, la percepción de bienestar psicológico y la percepción general de salud. En el caso de la adicción al consumo de tabaco, la preocupación por la salud actual o futura es uno de los motivos más informados para dejar de fumar. En el presente estudio se analiza la relación entre la percepción de la calidad de vida relacionada con la salud y la etapa de cambio en el abandono del consumo de tabaco propuesta desde el modelo transteórico a fin de mejorar las estrategias de intervención comunitaria y clínica para la cesación tabáquica. Se ha administrado el cuestionario SF-36 a una muestra formada por 201 fumadores y exfumadores. Los datos obtenidos indican peor salud física percibida en las etapas de cambio más próximas al abandono de tabaco y una peor salud mental percibida en las etapas con tabaquismo activo. Se comparan los resultados con los observados en otras poblaciones y se discuten las implicaciones a nivel de tratamiento y prevención del tabaquismo