Continuous-time mean-variance portfolio optimization in a jump-diffusion market

In this paper, we take up an approach of (Lindberg, in Bernoulli, 15(2):464–474, 2009) who introduced a new parameterization of the Black–Scholes model that allows for an easy solution of the continuous-time Markowitz mean-variance problem. We generalize the results of (Lindberg, in Bernoulli, 15(2):464–474, 2009) to a jump-diffusion market setting and slightly correct the proof and the assertion of the main result. Further, we demonstrate the implications of the Lindberg parameterization for the stock price drift vector in different market settings, analyse the dependence of the optimal portfolio from jump and diffusion risk and finally indicate how to use the method. We particularly also show how the optimal strategy can be obtained with the restricted use of historical data.     

Exploring PMOs through community of practice theory

This article explores project management offices (PMOs) through community of practice theory. Preliminary results from a national health care case study are used to confirm the legitimacy of this approach. Today's knowledge‐based economy calls for mechanisms to share knowledge. The issue of making more with less is at stake in order to reuse good practices, support innovative practice, and prevent the reinvention of the wheel. Members of these communities are at the heart of the learning process. The originality of this research is that it sheds light on PMOs in a new theoretical perspective within the field of knowledge management.     

The EU’s new competition policy standards

In a 2008 article in the EU’s Competition Policy Newsletter, Peter Lowe, Director General of the EU Commission’s Directorate Competition, synthesised the experience of his office with regard to the design of competition policy institutions for the 21st century. A year earlier, he had co-authored another article, appearing in the same venue, recapitulating the Commission’s lessons learned from the Energy Sector Inquiry and the need for effective unbundling of energy transmission networks. The reader of both, at first astounded by the apparent gap between policymaking reality and reflections upon it, soon detects a rather pragmatic approach to shaping regulatory agendas. But are there limits to expediency?     

Optimal portfolios with a positive lower bound on final wealth

We consider the determination of optimal portfolios under a lower bound on the final wealth. Possible applications range from capital guarantee strategies over life insurance investment where part of the benefit is a guaranteed return on capital to continuous-time mean-variance problems with a strictly positive lower bound. Our solution method consists of transforming the original problem into a portfolio problem without a positive lower bound but a transformed utility function and a modified initial wealth.     

A Bibliometric Review of Open Innovation: Setting a Research Agenda

Through an objective, systematic, and comprehensive review of the literature on open innovation (OI), this article identifies gaps in existing research, and provides recommendations on how hitherto unused or underused organizational, management, and marketing theories can be applied to advance the field. This study adopts a novel approach by combining two complementary bibliometric methods of co‐citation analysis and text mining of 321 journal articles on OI that enables a robust empirical analysis of the intellectual streams and key concepts underpinning OI. Results reveal that researchers do not sufficiently draw on theoretical perspectives external to the field to examine multiple facets of OI. Research also seems confined to innovation‐specific journals with its focus restricted to a select few OI issues, thereby exerting limited influence on the wider business community. This study reveals three distinct areas within OI research: (1) firm‐centric aspects of OI, (2) management of OI networks, and (3) role of users and communities in OI. Thus far, studies have predominantly investigated the firm‐centric aspects of OI, with a particular focus on the role of knowledge, technology, and R&D from the innovating firm's perspective, while the other two areas remain relatively under‐researched. Further gaps in the literature emerge that present avenues for future research, namely to: (1) develop a more comprehensive understanding of OI by including diverse perspectives (users, networks, and communities), (2) direct increased attention to OI strategy formulation and implementation, and (3) enhance focus on customer co‐creation and conceptualize “open service innovation.” Marketing (e.g., service‐dominant logic), organizational behavior (e.g., communities of practice), and management (e.g., dynamic capabilities) offer suitable theoretical lenses and/or concepts to address these gaps.     

Pflegeberatung ist Vertrauenssache

M?ngeln in der h?uslichen Pflege pr?ventiv begegnen – Vertrauen ohne Kontrolle, Routine, überforderung oder das Nichtbeachten des Beziehungsgeflechtes zwischen Pflegenden und Gepflegten führt oft zu Problemen. Der Gesetzgeber verpflichtete deshalb die Pflegekassen und Tr?gerverb?nde von ambulanten Pflegeeinrichtungen zur Erarbeitung von Richtlinien und standardisierten Verfahren für die Pflegefachberatung. Leider gibt es bislang keine verbindliche Umsetzung.     

Rationierung: Teufelszeug oder Herausforderung zum Umdenken?

Umgang mit knappen Ressourcen - Das Schreckgespenst der Rationierung macht sich im Gesundheitswesen breit und beunruhigt Patienten, Anbieter von Gesundheitsleistungen und den Gesetzgeber gleicherma?en. Pflegende befürchten, selbst Opfer oder Henkersknechte dieses Ph?nomens zu werden. Sind diese ?ngste begründet? Und – besteht die M?glichkeit zum Gegensteuern? Eine kritische Einsch?tzung von Ralf Gratias.     

Pricing assets with higher moments: Evidence from the Australian and us stock markets

This paper investigates the importance of higher moments of return distributions in capturing the variation of average stock returns for companies listed in the leading S&P US and Australian indices. We find that Australian stocks are more negatively skewed but less leptokurtic than US stocks. As a result, we find that co-skewness plays a more important role in explaining Australian returns while co-kurtosis is consistently influential for US stock returns. We postulate that the differences in results are related to the underlying firm characteristics of the companies in the two indices, where principally the Australian firms are noticeably smaller than their US counterparts and concentrated in a smaller number industry sectors. This implies that for many smaller exchanges around the world higher moment characteristics displayed by the US market may not be applicable. We also show our results are robust to partly explaining average stock returns in the presence of size, value, and momentum effects.