Portfolio selection theory, developed by Markowitz (1952), is one of the best known and widely applied methods for allocating funds among possible investment choices, where investment decision making is a trade-off between the expected return and risk of the portfolio. Many portfolio selection models have been developed on the basis of Markowitz's theory. Most of them assume that complete investment information is available and that it can be accurately extracted from the historical data. However, this complete information never exists in reality. There are many kinds of ambiguity and vagueness which cannot be dealt with in the historical data but still need to be considered in portfolio selection. For example, to address the issue of uncertainty caused by estimation errors, the robust counterpart approach of Ben-Tal and Nemirovski (1998) has been employed frequently in recent years. Robustification, however, often leads to a more conservative solution. As a consequence, one of the most common critiques against the robust counterpart approach is the excessively pessimistic character of the robust asset allocation. This thesis attempts to develop new approaches to improve on the respective performances of the robust counterpart approach by incorporating additional investment information sources, so that the optimal portfolio can be more reliable and, at the same time, achieve a greater return.

<p>Selection of right sets of projects is considerably critical for organizations to successfully achieve their competitive advantages and corporate strategies. Due to limited resources and dynamic changes in business environment, this kind of selection is quite challenging for organizations. Beside one hundred selection tools and techniques, academics and practitioners have studied and recommended complex selection frameworks to facilitate the selection of right projects. However, these theoretical frameworks are not applied by private corporations in Vietnam. Therefore, this dissertation is intended to better understand the academic and practical literature about project portfolio selection; study current practices of project selection that private corporations in Vietnam are using; and propose a framework that is beneficially adaptable to these private corporations. A multiple-case study strategy accessing qualitative data through observations and semi-structure interviews is designed to investigate how private corporations select their project portfolio under the current contexts of booming economy in Vietnam to ensure successful realization of their growth and development strategy. The recommendations resulted from literature review and investigations do not only support the investigated corporations to improve the quantity and quality of their investment project portfolio(s) but also facilitate possible adaptation to project portfolio selection by other private corporations.</p>

Sustainable development is becoming more and more essential in the way companies behave and perform. The concern regarding the environment and the society reflects a broader concept and perception on how business should be conducted. The continuous demand for all kind of resources makes it vital and almost inevitable for a company, government and even physical person to embrace and embed in their culture and strategic goals the sustainable development dimensions. In the perspective of project management, the integration of sustainability requires particular attention especially from the decision-makers involved in the field of project management and more precisely in the project selection process. This research aims to examine how this process is achieved by organizations in a sustainable manner, by proper integration in effective tools such as Environmental and Social Impact Assessment. The exploration of theories and models regarding project selection and ESIA helped me in building and elaborating further on a sustainable framework that enhances the need for proper integration and incorporation of environmental and social issues in projects. This paper concludes that the most efficient way to benefit from the opportunities that the surrounding environment brings in a project area is to assess such impacts and integrate them since the corporate strategy crafting and the initial phase of project selection process

Selection of right sets of projects is considerably critical for organizations to successfully achieve their competitive advantages and corporate strategies. Due to limited resources and dynamic changes in business environment, this kind of selection is quite challenging for organizations. Beside one hundred selection tools and techniques, academics and practitioners have studied and recommended complex selection frameworks to facilitate the selection of right projects. However, these theoretical frameworks are not applied by private corporations in Vietnam. Therefore, this dissertation is intended to better understand the academic and practical literature about project portfolio selection; study current practices of project selection that private corporations in Vietnam are using; and propose a framework that is beneficially adaptable to these private corporations. A multiple-case study strategy accessing qualitative data through observations and semi-structure interviews is designed to investigate how private corporations select their project portfolio under the current contexts of booming economy in Vietnam to ensure successful realization of their growth and development strategy. The recommendations resulted from literature review and investigations do not only support the investigated corporations to improve the quantity and quality of their investment project portfolio(s) but also facilitate possible adaptation to project portfolio selection by other private corporations.

With the advent of globalization and knowledge economic era, organizations have to face an increasingly competitive business environment. With limited resources, it is imperative for organizations to allocate them effectively, to focus on potential projects, to choose high value-added projects, and to find out the proper project portfolio. The purpose of this research is to investigate the decision model and the operational mechanism of project portfolio selection for military investment and to analyze the characteristics of related projects. Finally, this research mainly proposes a decision model for project portfolio selection and the measurement of portfolio performance and develops a portfolio selection decision support system to provide a communicative platform and information for decision makers and project managers. This will improve portfolio performance, reduce the crowding out effect of organizational resources, and enhance the linkage of both project and organizational goals.

This dissertation includes two topics. The first topic focuses on the problem of investor optimization of dynamic asset allocation to maximize expected utility under the value at risk (VaR) constraint. Different to previous researches, this study considers a common realistic case where the VaR horizon is equal to the whole investment horizon without a complete market constraint. Since the problem cannot be solved using the standard dynamic programming method or the martingale method, this study particularly provides an algorithm to solve this difficult problem. Similar to the mean-variance frontier suggested by Markowitz (1952), this study draws the frontiers of dynamic and static asset allocations under the VaR constraint. The analytical results clearly show that the dynamic asset allocations are more efficient than the static asset allocations. The second topic designs an optimal insurance policy form endogenously, assuming the objective of the insured is to maximize expected final wealth under the VaR constraint. The optimal insurance policy can be replicated using three options, including a long call option with a small strike price, a short call option with a large strike price, and a short cash-or-nothing call option. Moreover, expected wealth is increasing and concave in VaR and in significance level. Finally, Mean-VaR Frontiers are drawn, and reveal that the optimal insurance is more efficient than alternative insurance forms.

ABSTRACT PORTFOLIO SELECTION AND RETURN PERFORMANCE: An Application of the Black-Litterman Method in the Istanbul Stock Exchange Bozdemir, Mehmet Burak M.Sc, Department of Financial Mathematics Supervisor : Assist. Prof. Dr. Seza Dani

The increase in the types of airspace users (large aircraft, small and regional jets, very light jets, unmanned aerial vehicles, etc.), as well as the very limited number of future new airport development projects are some of the factors that will characterize the next decades in air transportation. These factors, associated with a persistent growth in air traffic will worsen the current gridlock situation experienced at some major airports. As airports are becoming the major capacity bottleneck to continued growth in air traffic, it is therefore primordial to make the most efficient use of the current, and very often, underutilized airport infrastructure. This research thus proposes to address the increase in air traffic demand and resulting capacity issues by considering the implementation of operational concepts and technologies at underutilized airports. However, there are many challenges associated with sustaining the development of this type of airports. First, the need to synchronize evolving technologies with airports' needs and investment capabilities is paramount. Additionally, it was observed that the evolution of secondary airports, and their needs, is tightly linked to the environment in which they operate. In particular, sensitivity of airports to changes in the dynamics of their environment is important, therefore requiring that the factors that drive the need for capacity expansion be identified and characterized. Finally, the difficulty to evaluate risk and make financially viable decisions, particularly when investing in new technologies, cannot be ignored. This work thus focuses on the development of a methodology to address these challenges and ensure the sustainability of airport capacity-enhancement investments in a continuously changing environment. The four-step process developed in this research leverages the benefits yielded by impact assessment techniques, system dynamics modeling, and real options analysis to 1) provide the decision maker with a rigorous, structured, and traceable process for technology selection, 2) assess the combined impact of interrelated technologies, 3) support the translation of technology impact factors into airport performance indicators, and help identify the factors that drive the need for capacity expansion, and finally 4) enable the quantitative assessment of the strategic value of embedding flexibility in the formulation of technology portfolios and investment options. The proposed methodology demonstrates, through a change in demand at the airport modeled, the importance of being able to weigh both the technological and strategic performance of the technology portfolios considered. Hence, by capturing the time dimension and technology causality impacts in technology portfolio selection, this work helps identify key technologies or technology groupings, and assess their performance on airport metrics. By embedding flexibility in the formulation of investment scenarios, it provides the decision maker with a more accurate picture of the options available to him, as well as the time and sequence under which these should be exercised.

The paper investigates dynamic optimal portfolio strategies of utility maximizing portfolio managers in the presence of risk constraints. Especially we consider the risk, that the terminal wealth of the portfolio falls short of a certain benchmark level which is proportional to the stock price. This risk is measured by the Expected Utility Loss. We generalize the findings our previous papers to this case. Using the Black-Scholes model of a complete financial market and applying martingale methods, analytic expressions for the optimal terminal wealth and the optimal portfolio strategies are given. Numerical examples illustrate the analytic results.

Univ., Diss.--St. Gallen, 2007. / Zsfassung in engl. Sprache.