New strategies and a new paradigm for Shariah-compliant portfolio optimization

In this paper we analyze the effects of different strategies to construct Shariah compatible financial portfolios. The difference between conventional and current Shariah portfolio management is the application of sector screens and financial screens by which the asset universe is reduced. Yet, here different schools of scholars define different screening rules leading to significant differences with respect to compliance, but also with respect to performance. After analyzing this discrepancy we propose several new strategies to apply the inconsistent rule systems and a new paradigm for defining Shariah-compliance. Under this new paradigm compliance is attributed to the portfolio and not to the individual assets of the universe. We report results of an empirical study analyzing the potentials of these strategies and of the paradigm. We can show that under the proposed concepts Shariah-compliant portfolios can be realized which have return and risk profiles comparable to the conventional non-constrained portfolios.     

The Effectiveness of Unconventional Monetary Policy in Japan

Since the global financial crisis of 2007–2008, central bankers around the world have been forced to abandon conventional monetary policy tools in favor of unconventional policies such as quantitative easing, forward guidance, and even lowering the interest rate paid on bank reserves into negative territory. Japan, which faced a crisis in its banking sector and came up against the theoretical zero lower bound on interest rates nearly a decade earlier, was a pioneer in the use of many of these unconventional policy tools. This article analyzes the effectiveness of Japan’s bold experiment with unconventional monetary policy. Using a panel of bi-annual bank data covering the full universe of Japanese commercial banks over a fifteen-year period, this study analyzes the effectiveness of quantitative easing policy on the bank lending channel of monetary policy transmission. Our findings suggest that Japan’s unconventional monetary policy worked: there is a bank lending channel of monetary policy transmission in Japan. These results are robust to the inclusion of time fixed effects and generalized method of moments analysis.     

Linear cumulative prospect theory with applications to portfolio selection and insurance demand

Abstract The present paper combines loss attitudes and linear utility by providing an axiomatic analysis of corresponding preferences in a cumulative prospect theory (CPT) framework. In a sense we derive a two-sided variant of Yaari’s dual theory, i.e., nonlinear probability weights in the presence of linear utility. The first important difference is that utility may have a kink at the status quo, which allows for the exhibition of loss aversion. Also, we may have different probability weighting functions for gains than for losses. We apply the model to both portfolio selection and insurance demand. Our results show that CPT with linear utility has more realistic implications than the dual theory since it implies only a weakened variant of plunging. Mathematics Subject Classification (2000): 91B08, 91B28, 91B30 Journal of Economic Literature Classification: D81, G11, G22     

Vertical Integration and Market Foreclosure with Convex Downstream Costs

Received December 14, 2000; revised version received July 16, 2001     

Semitractability of optimal stopping problems via a weighted stochastic mesh algorithm

In this paper, we propose a Weighted Stochastic Mesh (WSM) algorithm for approximating the value of discrete‐ and continuous‐time optimal stopping problems. In this context, we consider tractability of such problems via a useful notion of semitractability and the introduction of a tractability index for a particular numerical solution algorithm. It is shown that in the discrete‐time case the WSM algorithm leads to semitractability of the corresponding optimal stopping problem in the sense that its complexity is bounded in order by with being the dimension of the underlying Markov chain. Furthermore, we study the WSM approach in the context of continuous‐time optimal stopping problems and derive the corresponding complexity bounds. Although we cannot prove semitractability in this case, our bounds turn out to be the tightest ones among the complexity bounds known in the literature. We illustrate our theoretical findings by a numerical example.     

Challenges faced by world tourism cities – London’s perspective

World tourism cities perform multiple functions and exhibit various characteristics that influence tourism development within their boundaries. They are the main gateway for tourists visiting a country and their success has a direct impact on the visitor economy of that destination. London, the focus of this research, has been one of the world’s top tourism cities for many years, and a key gateway for domestic and international visitors. But despite the important role tourism plays in the economy of the city, there is limited research on the development of this activity in the capital. Using London as an exploratory case study, this paper contributes to better understanding the challenges faced by policy makers when planning and managing tourism in world cities. The adopted research method offers the advantage of gathering insightful information using multiple data collection techniques. Examining this new evidence contributes to expanding the knowledge on the particularities of tourism development in one of the top world cities, which could help policy makers in their efforts to better prepare for potential challenges faced by these complex but important destinations.     

Vertrauen als Gegenstand der ökonomischen Theorie

Der Beitrag vermittelt einen grundlegenden überblick über die Bedeutung des Vertrauens im Rahmen der ?konomischen Theorie. Zun?chst werden ausgew?hlte Ans?tze im Rahmen der betriebswirtschaftlichen Vertrauensforschung diskutiert. Um eine strukturierte Analyse zu erm?glichen, erfolgt eine differenzierte Betrachtung hinsichtlich der neoklassisch und institutionen?konomisch fundierten Perspektive einerseits sowie der sozio?konomischen Perspektive andererseits. Die Diskussion um den Stand der Forschung wird abgerundet durch einen überblick über empirische Ergebnisse der ?konomischen Vertrauensliteratur. Um noch offene Fragen im Rahmen der Forschung zu adressieren, werden im Anschluss die unterschiedlichen Objekte des Vertrauens analysiert, differenziert nach personalen Vertrauen und Systemvertrauen. Zum Abschluss gilt es die Verhaltensrisiken herauszuarbeiten, die mit Vertrauensbeziehungen einhergehen und die Grenzen des Vertrauens in Organisationen zu beleuchten.