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.     

What does it mean to find the face of the franchise? Physical attractiveness and the evaluation of athletic performance

We show that attractiveness, as measured by facial symmetry, leads to greater rewards in professional sports. National Football League quarterbacks who are more attractive are paid greater salaries and this premium persists after controlling for player performance.     

Environmental impacts of changes to healthier diets in Europe

Food consumption causes, together with mobility, shelter and the use of electrical products, most life cycle impacts of consumption. Meat and dairy are among the highest contributors to environmental impacts from food consumption. A healthier diet might have less environmental impacts. Using the E3IOT environmentally extended input output database developed in an EU study on Environmental Impacts of Products (EIPRO), this paper estimates the difference in impacts between the European status quo and three simulated diet baskets, i.e. a pattern according to universal dietary recommendations, the same pattern with reduced meat consumption, and a ‘Mediterranean’ pattern with reduced meat consumption. Production technologies, protein and energy intake were kept constant. Though this implies just moderate dietary shifts, impact reductions of up to 8% were possible in reduced meat scenarios. The slightly changed food costs do not lead to significant first order rebound effects. Second order rebounds were estimated by applying the CAPRI partial equilibrium model. This analysis showed that European meat production sector will most likely respond by higher exports to compensate for losses on the domestic meat market. Higher impact reductions probably would need more drastic diet changes.     

Industry dynamics: Foundations for models with an infinite number of firms

This paper explores the connection between three important threads of economic research offering different approaches to studying the dynamics of an industry with heterogeneous firms. Finite models of the form pioneered by Ericson and Pakes (1995) capture the dynamics of a finite number of heterogeneous firms as they compete in an industry, and are typically analyzed using the concept of Markov perfect equilibrium (MPE). Infinite models of the form pioneered by Hopenhayn (1992), on the other hand, consider an infinite number of infinitesimal firms, and are typically analyzed using the concept of stationary equilibrium (SE). A third approach uses oblivious equilibrium (OE), which maintains the simplifying benefits of an infinite model but within the more realistic setting of a finite model. The paper relates these three approaches. The main result of the paper provides conditions under which SE of infinite models approximate MPE of finite models arbitrarily well in asymptotically large markets. Our conditions require that the distribution of firm states in SE obeys a certain “light-tail” condition. In a second set of results, we show that the set of OE of a finite model approaches the set of SE of the infinite model in large markets under a similar light-tail condition.     

PAALiativ: Technik als Chance?

Assistenztechnologie im Wohnumfeld — Die Terminalphase des Lebens in h?uslicher Umgebung verbringen zu k?nnen entspricht dem Wunsch der meisten Menschen. In Oldenburg startete mit PAALiativ ein Projekt, mit dem exemplarisch nach M?glichkeiten der technischen Unterstützung für ein selbstbestimmtes Leben Schwerstkranker gesucht wird.     

Süchtige Sammler

Wohnungsdesorganisation bei Sucht - Chaotische Wohnverh?ltnisse lassen sich oft auf eine Suchterkrankung zurückführen. Dabei kann man einen deutlichen Unterschied zwischen Wohnungen von Menschen mit einer Kaufsucht und denen von Menschen mit psychischen St?rungen und Verhaltensst?rungen durch psychotrope Substanzen beobachten.     

Strategic Debt in Vertical Relations: Evidence from Franchising

In this paper, we examine the strategic use of debt in franchise organizations. We focus on both the franchisee's and the franchisor's capital structures. The primary goal of this study is to examine whether franchisors impose limits on franchisees’ debt levels to be able to increase their own leverage. We find that the franchisor's leverage is significantly related to the maximum leverage allowed for the franchisee. As the franchisor sets an upper limit on the franchisee's debt ratio, the franchisor can raise more debt and therefore seizes tax benefits, since interest payments are tax deductible. We find that this effect is stronger in chains with larger fractions of franchised outlets.     

Mein Partner ist dement

LebensAufgabe für pflegende Angeh?rige — Die Betreuung und Pflege eines demenziell erkrankten Familienangeh?rigen stellt nahe Bezugspersonen vor gro?e Herausforderungen. Ohne Unterstützungsangebote brechen viele unter der Last des Alltags zusammen. Pflegekr?fte sollten daher die Belastungsgrenzen von Angeh?rigen erkennen und ihnen rechtzeitig professionelle Hilfe anbieten.