Intraday Empirical Analysis and Modeling of Diversified World Stock Indices

This paper proposes an approach to the intraday analysis of diversified world stock accumulation indices. The growth optimal portfolio (GOP) is used as reference unit or benchmark in a continuous financial market model. Diversified portfolios, covering the world stock market, are constructed and shown to approximate the GOP, providing the basis for a range of financial applications. The normalized GOP is modeled as a time transformed square root process of dimension four. Its dynamics are empirically verified for several world stock indices. Furthermore, the evolution of the transformed time is modeled as the integral over a rapidly evolving mean-reverting market activity process with deterministic volatility. The empirical findings suggest a rather simple and robust model for a world stock index that reflects the historical evolution, by using only a few readily observable parameters. Mathematics Subject Classification: (1991) primary 90A12, secondary 60G30,62P20 JEL Classification: G10, G13     

Value creation in the relationship life cycle: A quasi-longitudinal analysis

Among the growing literature on value creation in collaborative buyer-seller relationships, most researchers examine relationship value at a single point in time. In the present research, we explore whether different stages of the relationship life cycle moderate the relative importance of value-creating dimensions. To shed light on the dynamic nature of value in B2B relationships, we present the results of a survey among purchasing managers using a quasi-longitudinal research design. Our findings confirm the moderating role of the relationship life cycle in value creation. More precisely, our results indicate that a key supplier's potential for value creation in customer's operations increases in relative importance as relationships move through the life cycle. In turn, supplier's capabilities to create superior value at the level of the customer's sourcing process display a decreasing role over the life cycle of a business relationship. No significant link was found in the present study between value creation through a supplier's core offering and different stages of a buyer-seller relationship.     

Lutz M. Hagen,Technische Universität Dresden

Ohne Zusammenfassung     

Corporate Governance and Expected Stock Returns: Evidence from Germany

Recent empirical work shows evidence for higher valuation of firms in countries with a better legal environment. We investigate whether differences in the quality of firm‐level corporate governance also help to explain firm performance in a cross‐section of companies within a single jurisdiction. Constructing a broad corporate governance rating (CGR) for German public firms, we document a positive relationship between governance practices and firm valuation. There is also evidence that expected stock returns are negatively correlated with firm‐level corporate governance, if dividend yields are used as proxies for the cost of capital. An investment strategy that bought high‐CGR firms and shorted low‐CGR firms earned abnormal returns of around 12% on an annual basis during the sample period.     

The inflation game

We study a game where households buy consumption goods to preempt inflation. This game features a unique equilibrium with high (low) inflation, whenever money supply is high (low). For intermediate levels of money supply, there exist multiple stable equilibria where inflation is either high or low. Equilibria with moderate inflation, however, do not exist, and can thus not be targeted by central banks. That is, depending on agents' equilibrium play, money supply is always either too high or too low for moderate inflation. Finally, we find that inflation rates of durable goods, such as houses, cars, luxury watches, or furniture, are useful leading indicators for changes in overall inflation.     

Laying the foundations of international careers research

As an editorial to the special issue “new avenues in international careers research” this article discusses the roots of the international careers research stream, which sits at the intersection between career studies, HRM and international management. In order to support future studies in this emerging area of enquiry, we attempt to lay down the foundations of a research agenda based around what we see as the three core areas of interest: contextualised careers research, comparative careers research and careers research in internationally operating organisations. After providing some suggestions for the kinds of theoretical and methodological tools that will be required to build on these foundations, we introduce the five empirical papers that comprise this special issue.     

Digitalisierung im Gesundheitswesen — zwischen Datenschutz und moderner Medizinversorgung

The digital transformation of the healthcare branch is important and unstoppable. The enormous possibility of digitalisation to redesign and enhance processes has been shown in other branches. Digital technologies offer the similarly large potential to improve the quality and efficiency of healthcare services. However, in terms of digitalisation, the German health system lags behind other European countries. But given a lack of available evidence, the effects of the digitalisation of the healthcare system cannot be reliably evaluated. Digital access to patient data necessitates constructive error cultures in organisations in order to limit defensive medicine. And digital access to health information necessitates individual competence in searching and using this information for participatory decision-making. As with all technological progress, information security is very important in order to gain citizens’ confidence in a digital healthcare system. Thus, it is necessary to simultaneously pursue both enhanced privacy standards and state-of-the-art medical technology.