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.     

Optimal Portfolios with Bounded Capital at Risk

We consider some continuous-time Markowitz type portfolio problems that consist of maximizing expected terminal wealth under the constraint of an upper bound for the capital at risk. In a Black–Scholes setting we obtain closed-form explicit solutions and compare their form and implications to those of the classical continuous-time mean-variance problem. We also consider more general price processes that allow for larger fluctuations in the returns.     

Portfolio optimization based on GARCH-EVT-Copula forecasting models

This study uses GARCH-EVT-copula and ARMA-GARCH-EVT-copula models to perform out-of-sample forecasts and simulate one-day-ahead returns for ten stock indexes. We construct optimal portfolios based on the global minimum variance (GMV), minimum conditional value-at-risk (Min-CVaR) and certainty equivalence tangency (CET) criteria, and model the dependence structure between stock market returns by employing elliptical (Student-$t$ and Gaussian) and Archimedean (Clayton, Frank and Gumbel) copulas. We analyze the performances of 288 risk modeling portfolio strategies using out-of-sample back-testing. Our main finding is that the CET portfolio, based on ARMA-GARCH-EVT-copula forecasts, outperforms the benchmark portfolio based on historical returns. The regression analyses show that GARCH-EVT forecasting models, which use Gaussian or Student-$t$ copulas, are best at reducing the portfolio risk.     

When Organizational Justice Matters for Affective Merger Commitment

We investigate when organizational justice matters to employees’ commitment in the postacquisition process after a company is taken over in a cross‐border acquisition. Overwhelming evidence from the literature suggests that employees who are treated fairly during acquisitions are more committed to their new firms. We extend this finding by dividing organizational justice into three subdimensions: informational justice, interpersonal justice, and procedural justice. We find evidence that procedural justice is an important antecedent of affective merger commitment at an early stage of the integration period, while informational justice becomes important at a later stage. Further analysis on heterogeneity between the target firm's employees and the bidder firm's employees reveals that, immediately after the acquisition, target firm's employees value knowing where they will be at the new firm (procedural justice), while bidder firm employees are more concerned about communication and transparency (informational justice). Our results point to the importance of organizational justice in a cross‐border merger and acquisition (M&A) setting and the need for a separate study of issues related to bidder firms and target firms. © 2016 Wiley Periodicals, Inc.     

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.