投资组合理论中的组合选择问题研究

经典的Markowitz投资组合理论在选择最优投资组合时，没有考虑到投资实践中大量存在的委托代理关系，从而使得最优投资组合的选择可能会偏离投资者的利益。本文对这一问题做了详细的描述，并对目前解决此问题的方法，即委耗投资组合管理的原理进行了分析。     

项目组合选择研究：基于模糊理论的模型建构及验证

项目组合的选定与企业经营息息相关，然而传统的选择方法存在许多限制。本文应用模糊理论建构一个项目组合的决策模型，模型中纳入了成本、利润及风险等3个决策因子，探讨在资源有限的情况下项目成本及获利的交互影响关系，并利用模糊归属函数建构一个数学规划模型。为了验证模型的有效性，用此模型与传统模型进行求解比较，证实了所提出模型的实用性。     

ERRATUM TO “BEHAVIORAL PORTFOLIO SELECTION IN CONTINUOUS TIME”

We fill a gap in the proof of a (rather critical) lemma, Lemma B.1, in Jin and Zhou (2008: Math. Finance 18, 385–426). We also correct a couple of other minor errors in the same paper.     

BEHAVIORAL PORTFOLIO SELECTION: ASYMPTOTICS AND STABILITY ALONG A SEQUENCE OF MODELS

We consider a sequence of financial markets that converges weakly in a suitable sense and maximize a behavioral preference functional in each market. For expected concave utilities, it is well known that the maximal expected utilities and the corresponding final positions converge to the corresponding quantities in the limit model. We prove similar results for nonconcave utilities and distorted expectations as employed in behavioral finance, and we illustrate by a counterexample that these results require a stronger notion of convergence of the underlying models compared to the concave utility maximization. We use the results to analyze the stability of behavioral portfolio selection problems and to provide numerically tractable methods to solve such problems in complete continuous‐time models.     

Is ‘oil and gas’ industry of ASEAN5 countries integrated with the US counterpart?

ABSTRACT

This paper employs the VARMA-MGARCH-ABEKK model and Granger causality on 15 years’ daily time series data to examine investment opportunities in the oil and gas industries for ASEAN5 countries relative to the US counterpart. It shows that the latter leads the former in decomposing integration into cross-country effects on returns and conditional return volatilities. The empirical results show that investors can gain an international intra-industry diversification benefit in Malaysia, the Philippines, Singapore and Vietnam by holding US oil and gas assets in their portfolios whereas Asian oil and gas assets may result in negative shocks due to the increase in return volatilities for Malaysia, Singapore and Vietnam. However, Thailand are insensitive to the cross-country intra-industry diversification. While making trading decisions, investors should be aware of the impulse responses of ASEAN oil and gas markets from the shocks in the US and the Asian markets and their asymmetric spill over effects.     

Modeling a Dynamic Portfolio for Pension Plans in Emerging Markets With Myopic and Nonmyopic Behavior

ABSTRACT

We introduce a dynamic formulation for the problem of portfolio selection of pension funds in the absence of a risk-free asset. In emerging markets, a risk-free asset might be unavailable, and the approaches commonly used may no longer be suitable. We use a parametric approach to combine dynamic programming and Monte Carlo simulation to gain additional flexibility. This approach is general in the sense that optimal asset allocation is tractable for all HARA utility functions in the absence of a risk-free asset. The traditional case composed of several risky assets and one risk-free asset is compared to a case in which the risk-free asset is unavailable.     

An Improvement of the Parameter Certainty Equivalence Method in Portfolio Selection

This paper discusses an improvement of the Parameter Certainty Equivalence method in portfolio selection. Specifically, we derive methods of portfolio selection that are superior to the Parameter Certainty Equivalence method from the viewpoint of maximizing expected utility. We additionally derive such a method from the Bayesian approach.     

Portfolio selection with skewness: A multiple-objective approach

In the presence of skewness, the portfolio selection entails considering competing and conflicting objectives, such as maximizing both its expected returns and skewness, and minimizing its risk for decreasing absolute risk-aversion investors. Since it is unlikely that a portfolio can solve the multiple-objectives problem simultaneously, a portfolio selection must depend on the investor's preference among objectives. This article shows that investor preference can be incorporated into a polynomial goal programming problem from which a portfolio selection with skewness is determined. An inefficient mean-variance portfolio may be optimal in the mean-variance-skewness content. The features of applying polynomial goal programming in portfolio selection are 1) the existence of an optimal solution, 2) the flexibility of the incorporation of investor preference, and 3) the relative simplicity of computational requirements.     

证券组合投资的风险溢价模型

本文探讨了单周期证券市场中投资组合的风险溢价模型,该模型类似于资本资产定价模型。     

¿Han sido el IBEX35 y el IPC definiciones financieramente eficientes del portafolio de mercado?

The present paper questions the financial efficiency of the most used market portfolio proxies in Spain and Mexico (IBEX35 and IPC) in order to determine if these can be considered a proper market portfolio proxy. The paper questions if they can be used as “neutrals”, according to Black & Litterman (1992) proposals in portfolio management. For this purpose, two discrete event simulations that use the Markowtiz-Tobin-Sharpe-Linter model (Markowitz, 1987, p.5) are performed with monthly data of the stock members of these indices in a February 2001 to December 2010 time window. The results are compared by using the Sharpe ratio (Sharpe, 1966) and show that the equilibrium assumptions in the market do not hold, leading to conclude that these market portfolio proxies are inefficient.