This study examines the long memory behavior in gold returns during the post-Bretton Woods period using a new rescaled range technique. Unlike the conventional rescaled range analysis, the new rescaled range analysis is robust to short-term dependence and conditional heteroscedasticity found in the gold data. Statistical results suggest that the long memory behavior in gold returns is rather unstable. When only few observations corresponding to major political events in the Middle East, together with the Hunts event, in late 1979 are omitted, little evidence of long memory can be found. 相似文献
Graphical models provide a powerful and flexible approach to the analysis of complex problems in genetics. While task-specific software may be extremely efficient for any particular analysis, it is often difficult to adapt to new computational challenges. By viewing these genetic applications in a more general framework, many problems can be handled by essentially the same software. This is advantageous in an area where fast methodological development is essential. Once a method has been fully developed and tested, problem-specific software may then be required. The aim of this paper is to illustrate the potential use of a graphical model approach to genetic analyses by taking a very simple and well-understood problem by way of example. 相似文献
Zusammenfassung Koordinierte Strategien für wirtschaftliche Zusammenarbeit zwischen Europa und den Vereinigten Staaten. - In diesem Aufsatz
wird die dynamische Spieltheorie auf die Koordinierung der Politik zwischen den Vereinigten Staaten und der EWG in einem stark
aggregierten Modell angewandt und folgendes gezeigt: (i) Eine Politik, die den Einflu\ von Ma\nahmen anderer L?nder vernachl?ssigt,
führt in den USA zu Fiskalischen Einschr?nkungen und einer Verminderung der staatlichen Interventionen, in Europa dagegen
zu einer Nachfragestimulierung, verbunden mit einer kontinuierlichen Herabsetzung des Diskontsatzes. Die EWG-L?nder sind,
da sie ihre Politik nicht koordinieren, nach einigen Jahren wegen Zahlungsbilanzschwierigkeiten zu einer kontraktiven Nachfragepolitik
gezwungen. (ii) Koordinierte Strategien best?tigen, da\ nicht-synchronisierte Politiken die Weltwirtschaft stabilisieren k?nnen.
(in) Kooperation verbessert die wirtschaftlichen Leistungen, ausgedrückt in den Wachstumsraten und den Zahlungsbilanzen. Allerdings
erbringt die ausdrückliche Zusammenarbeit kaum noch zus?tzliche Vorteile zu denen, die bereits im Rahmen der vollen Koordinierung
erreicht werden k?nnen.
Resumen Estrategias coordinadas de cooperación económica entre Europa y los EEUU.- La aplicación de un modelo dinámico de teoría de
juegos a la coordinatión de política económica entre los EEUU y la CEE, como parte de un modelo altamente agregado de la economía
mundial, permite concluír en este trabajo que (i) políticas que ignoran la influencia de medidas tomadas en otros países dan
lugar a una contractión fiscal y a una menor interventión del Gobierno en los EEUU, pero a una estimulación de la demanda
combinada con reducciones continuas de la tasa de descuento en Europa; al seguir políticas descoordinadas los países de la
CEE están obligados a contraer la demanda agregada al cabo de unos a?os, debido a los problemas de balance de pagos, (ii)
estrategias coordinadas confirman que políticas no sincronizadas pueden estabilizar la economía mundial; (iii) la cooperación
favorece a la economía en términos de tasas de crecimiento y balance de pagos. Sin embargo, los beneficios adicionales de
una cooperatión explícita resultan marginales en comparación con los beneficios ya alcanzados por la solución con coordinación
total.
Résumé Stratégies coordonnées pour la coopération entre l’Europe et les E.U. - En appliquant la théorie dynamique de jeu à la coordination
de politique entre les E.U. et la CEE dans un modèle fortement agrégé de l’économie mondiale, cet article arrive aux conclusions
suivants: (i) La politique qui ignore l’influence des actions suivies dans d’autres économies mène à la réduction fiscale
et à moins interventions gouvernementales dans les E.U., mais à une stimulation de la demande avec des réductions continuelles
du taux d’escompte en Europe. En cas d’une politique pas coordonnée les pays CEE sont forcés à prendre des mesures pour freiner
la demande agrégée après quelques années à cause des problèmes de la balance des paiements. (ii) La stratégie coordonnée confirme
que des politiques pas synchronisées pourraient stabiliser l’économie mondiale. (iii) La coopération peut élever le taux de
croissance et améliorer la balance des paiements. Cependant, les gains additionnels d’une coopération explicite sont petits
en comparaison avec les bénéfices déjà gagnés à l’aide d’une solution complètement coordonne’e.
We use a vertical product differentiation model under partial market coverage to study the social welfare optimum and duopoly equilibrium when convex costs of quality provision are either fixed or variable in terms of production. We show the following new results. First, under fixed costs, the social planner charges a uniform price for the single variant that just covers costs of quality provision. Like the duopoly equilibrium, this socially optimal pricing entails a partially uncovered market, but a smaller share of the market is served compared with the duopoly equilibrium. Second, for the variable cost case, it is socially optimal to provide both high‐ and low‐quality variants, but market shares need not be equal. This differs from the result in fully covered markets. Third, in the duopoly equilibrium, the quality spread is too wide under variable costs relative to the social optimum. Under fixed costs, the duopoly produces two variants, but quality is too low relative to the social optimum, which has only one variant. 相似文献
The South African research community which undertakes all research activity in the social and natural sciences, with and without state and corporate sponsorship, draws its membership mainly from the dominant social group. In this country, the dominant group is both economically and racially determined. Consequently, the white minority dominates the research community and intellectual discourse as it does other socio‐economic and political spheres of society. This situation guarantees the constant reproduction and perpetuation of the social relations of racial domination.
As an agent that generates knowledge and new ideas, research as an academic and intellectual tool of enquiry is an instrument of social control, producing new concepts, language and theoretical abstractions which are not accessible to those outside its multi‐farious disciplines. Insofar as the largest proportion of practitioners of these specialised disciplines is drawn from the dominant group, research has itself become a pivotal part of the dominant ideology. Its role is inevitably and inextricably bound up with the processes of systematic reproduction of the relations of domination.
The aim of this viewpoint is therefore to explore various ways in which research bodies and intellectual discourse in general in South Africa can be deracialised and be made more representative of the social make‐up of society. 相似文献
Many more than ever face the crises of childhood: violence, drugs, bad schools, poverty, divorce, or two parents at work. And no one seems to care. 相似文献