Monitoring the mean and the variance of a stationary process

We deal with the problem of how deviations in the mean or the variance of a time series can be detected. Several simultaneous control charts are introduced which are based on EWMA (exponentially weighted moving average) statistics for the mean and the empirical variance. The combined X − S² EWMA chart is extended to time series. Further simultaneous charts are considered. The comparision of these schemes shows that the residual attempt must be favored if a variance change is present.     

Phase transition in the S&P stock market

We analyze the returns of stocks contained in the Standard & Poor’s 500 index from 1987 until 2011. We use covariance matrices of the firms’ returns determined in a time windows of several years. We find that the eigenvector belonging to the leading eigenvalue (the market) exhibits a phase transition. The market is in an ordered state from 1995 to 2005 and in a disordered state after 2005. We can relate this transition to an order parameter derived from the stocks’ beta and the trading volume. This order parameter can also be interpreted within an agent-based model.     

Fiscal strategies,foreign indebtedness,and overlapping generations

Conclusions This paper offers a unifying dynamic system approach to real government debt and real capital formation in a world economy. The sustainability of permanently maintained primary fiscal deficits is investigated in an open economy. In particular if national governments compete in the issuance of debt at an international capital market sustainable debt profiles appear only as a theoretical (i. e., not empirically valid) curiosity. Within the more realistic regime of an undercapitalized world economy a nation can only run a permanently maintained primary surplus. Starting from a PMP surplus the paper also demonstrates the viability of temporary deficits implying an increase in taxation later to stabilize the fiscal debt. By reversing the argument this shows, the right way to reduce government debt in a non-traumatic manner is to run a higher temporary surplus via higher taxation. Using this extrasurplus to buy back fiscal debt the economy may reduce taxation later while enjoying vigorous capital accumulation towards a higher capital-labour ratio. Furthermore, the paper shows that ceteris paribus a relatively high social security load and a relatively high size of a balanced budget causes external indebtedness via consumption oriented current account deficits. It is left for further research to see what happens if government borrows for public investment instead of public consumption.My research was supported by Deutsche Forschungsgemeinschaft. While preparing the paper 1 had access to unpublished work by M. Carlberg and T. Ihori. Discussions with M. Carlberg, H. Großmann, J. Michaelis, and H. Schmid are gratefully acknowledged. The diagrams were mastered by C. Schwarz.     

The development of critical capabilities in foreign subsidiaries: disentangling the role of the subsidiary’s business network

Within business literature in general, capabilities have advanced to the prime determinant of the corporation’s economic rents. Within international business literature, it is further assumed that multinational corporations can enhance their pool of capabilities through foreign subsidiaries. Foreign subsidiaries are seen as means to assimilate new capabilities from their local, external network and integrate these capabilities into the multinational corporation. Data from more than 2000 foreign subsidiaries shows that some foreign units actually are endowed with superior capabilities which are useful for other corporate entities. It is argued that the development of critical capabilities within these subsidiaries is driven not only by internal corporate actors, but also by external actors. The analysis provides evidence that the role of different internal and external network partners for capability development varies according to the functional activity under consideration. Thus, subsidiaries benefit from various internal and external network actors in very different ways. The contribution ends with some conclusions and some avenues for future research.     

Planning with scenarios : The banking world of 1985

Scenarios are widely used in large organisations as a planning tool. The success of this tool, however, depends on its ability to link macroviews of economic, social, and political events to the unique operating experience of a specific type of organisation. This article describes a formal linking procedure for assessing the impact of several scenarios on a large bank. The goal is to define those sets of economic, technological, and regulatory conditions which are most favourable (a “best scenario”) and those which are least favourable (a “worst scenario”).     

Short-term capital flows under flexible exchange rates

Zusammenfassung Kurzfristige Kapitalbewegungen bei flexiblen Wechselkursen. — In dieser Arbeit werden die kurzfristigen Kapitalzuflüsse in ihrer Eigenschaft als ausl?ndische Nachfrage nach heimischem Geld behandelt. Unter diesem Aspekt hat ein exogener Zufluβ bei flexiblen Wechselkursen eine unmittelbar deflation?re Wirkung. Auβerdem werden die wechselkursinduzierten kurzfristigen Kapital-bewegungen in einem einfachen makro?konomischen Modell analysiert. Selbst wenn man den mehr traditionellen Typ von zinselastischen Kapitalbewegungen in dem Modell berücksichtigt, führt der hier gew?hlte Ansatz zu bedeutsamen Modifikationen der Standardargumentation.

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Résumé Les flux des capitaux à court terme sous les conditions de cours de change flexibles. — Cet article se concentre sur les afflux des capitaux à court terme compris comme démande extérieure en faveur d’argent local. Un afflux exogène sous cet angle a un effet directement déflationniste sous les conditions de cours de change flexibles. De plus, cet article analyse le r?le des afflux des capitaux à court terme induits par le cours de change. Même en considérant le type plus traditionel des flux des capitaux étant élastique envers l’intérêt dans notre modèle cette approche mène aux qualifications signifiantes du modèle de standard.

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Resumen Flujos de capital de corto plazo bajo tasas de cambio flexibles. — Este artículo se concentra sobre los influjos de capital de corto plazo considerados como demanda extranjera por moneda doméstica. Un influjo exógeno tiene, bajo este punto de vista, un efecto deflatorio directo bajo tasas de cambio flexibles. Además, este articulo analiza el rol de los flujos de capital de corto plazo inducidos por variaciones en la tasa de cambio en un modelo macro-económico simple. Incluso considerando en nuestro modelo flujos de capital elásticos con respecto a la tasa de interés del tipo más tradicional, este enfoque nos muestra cualificaciones significativas del modelo standard.