Portfolio Fishing

The optimal fishing pattern in a multi-cohort fishery is determined using risk theory.Portfolio theory becomes applicable by treating different age groups of fish as different assets. A possibility set is derived using data on Icelandic cod fisheries. In the presence of risk aversion, it is shown that the abrupt behavior found in deterministic models is changed towards a smoother fishing pattern. The historical selection pattern for the Icelandic cod stock is shown to be near optimal using a maximal effort-type cost function, but historical levels of effort are inefficient and lead to less profit and greater fluctuations than implied by profit or utility maximization.     

基于核心能力的公司业务组合

本文指出基于核心能力的公司业务组合才能使企业保持持续的竞争优势,并分析了在核心能力的导向下,企业如何进行公司业务组合。     

组态视角下考虑伙伴重复性的联盟组合创新绩效提升路径研究

创新绩效是衡量联盟组合效果的重要指标,也是企业组建联盟的首选目标之一。基于2014—2020年我国15家医药制造企业数据,运用模糊集定性比较分析法和二维复合变量对联盟组合规模进行测度,从组态视角分析联盟数量、伙伴重复性、联盟组合管理能力对联盟组合创新绩效的作用机理,获取多条高创新绩效提升路径。结果发现,实现高创新绩效有两条路径,分别为中等联盟数量和中等伙伴重复性组态路径、中等联盟数量和高联盟组合管理能力组态路径。因此,企业在构建联盟组合过程中应根据适度原则,控制联盟数量和伙伴重复性;同时,从前瞻规划、组合构建、关系优化和组合协调4个方面提高联盟组合管理能力,这为企业联盟组合管理实践提供了重要启示。     

Adaptive Portfolio Allocation with Options

We conducted a laboratory experiment of repeated portfolio allocation choice between a bond, a stock, and a put option on the stock. The study involves two conditions: a full hedging possibility and a partial hedging possibility. Surprisingly, participants were able to converge to the mean-variance frontier in the environment with partial hedging possibilities, but were unable to do so in the full hedging condition. This suggests that subjects may not be cognizant of the mean-variance frontier. If subjects begin away from the frontier and have to adjust toward it, incentives off the frontier are critical. Simulations of adaptive dynamic models confirm this assertion. The study provides insight into the adaptive behavior of investors in the presence of hedging possibilities and implications for efficient investment strategies.     

Portfolio Choice under Uncertain Lifetime

This paper revisits the theory on life cycle savings and portfolio choice under uncertain lifetime emphasizing the role of temporal risk aversion. It provides new insights on the impact of mortality rates on optimal financial strategies. This is of particular interest for the management of pension funds.     

Portfolio delegation under short-selling constraints

Summary. In this paper we study delegated portfolio management when the manager’s ability to short-sell is restricted. Contrary to previous results, we show that under moral hazard, linear performance-adjusted contracts do provide portfolio managers with incentives to gather information. We find that the risk-averse manager’s effort is an increasing function of her share in the portfolio’s return. This result affects the risk-averse investor’s choice of contracts. Unlike previous results, the purely risk-sharing contract is now shown to be suboptimal. Using numerical methods we show that under the optimal linear contract, the manager’s share in the portfolio return is higher than what it is under a purely risk sharing contract. Additionally, this deviation is shown to be: (i) increasing in the manager’s risk aversion and (ii) larger for tighter short-selling restrictions. As the constraint is relaxed the deviation converges to zero.Received: 25 July 2002, Revised: 12 December 2004, JEL Classification Numbers: D81, D82, J33.Juan-Pedro Gómez: Correspondence toAn earlier version of the paper was circulated under the title “Providing Managerial Incentives: Do Benchmarks Matter?” We are grateful to an anonymous referee whose comments helped to improve the paper. We also thank comments by Viral Acharya, Alexei Goriaev, Ernst Maug, Kristian Rydqvist, Neil Stoughton, Rangarajan Sundaram, Fernando Zapatero and seminar participants at the 1999 SED meetings in Sardinia, the 1999 Workshop in Mutual Fund Performance at EIASM, Brussels, the 2000 EFA meetings in London, the Bank of Norway, the Stockholm Schools of Economics, the Norwegian School of Management and the 2001 WFA meetings in Tucson. Sharma gratefully acknowledges financial support from the Asociacion Mexicana de Cultura.     

Portfolio crowding out and inflation

Although the relationship between inflation and financial investment decisions has long been studied, the literature has failed to recognise its importance for the crowding out issue, i.e. for whether increases in the stock of government debt reduce the equilibrium price of capital. This paper shows that when investors are concerned with real, as opposed to nominal, returns on their portfolios the conclusion of portfolio crowding out may be overturned, other things being equal, by changes in the expected rate of inflation.     

略论投资组合管理的几个问题

在国内，随着基金和资产管理机构的大量涌现，投资组合管理的重要性得以凸现。在投资组合管理的目标——管理——评价的每一阶段，都是以当代金融学、财务学的理论为基础，以定量分析和计算机为手段，以大量的数据库为支撑的。投资组合管理与个股投资有很大不同，需要作专门研究。     

Portfolio management with tail dependence

Many publications, that treated with Portfolio Management, were devastating for all asset allocation models in the context of portfolios. The elimination of extreme events (asymmetric or tail dependence) during the portfolio construction process can reduce the skills of asset managers to reduce risk through diversification. The copula theory allows us to calculate an alternative to measure the dependence of extreme events in assets through the index lower tail dependence. We check that the strategies with tail dependence overcame Talmud rule, the Markowitz model and the model of Tu and Zhou by simulating 1,000 portfolios with 3, 5, 10 and 20 randomly selected assets from DJIA for the period 03/1990 until 12/2016. We conclude that models of tail dependence and Markowitz had more performance ex-ante than Talmud and the Tu and Zhou model for portfolios with 3, 5, 10 and 20 assets. Tail dependence models overcome Markowitz, in terms of cumulative return, in over 60% of months considered in the analysis. The results indicate that the Talmud rule should be discarded in a context of constructing portfolios with individual stocks ahead strategies with tail dependence.     

Portfolio optimization through Kriging methods

This article presents a new methodology for optimizing financial asset portfolios. The proposed methodology, based on the Kriging method, allows for approximating the risk surface – and thus the optimal solution to the problem – in a generalized fashion, relaxing every restrictive hypothesis inherent to the available methods and with the ability to estimate the error in the risk surface approximation. Illustratively, the proposed methodology is applied to the portfolio problem with the Variance, VaR and CVaR as objective functions. The results are compared to those obtained using the Khun–Tucker technique, for the former, and the Rockafellar method, for the latter.     

Portfolio selection by Austrian insurance companies

Zusammenfassung Ausgehend von einem modifizierten Modell vonParkin (1970) wird versucht, das Anlageverhalten der österreichischen Vertragsversicherungen ökonometrisch zu erfassen. In diesem Modell wird das gewünschte Portefeuille abhängig von den erwarteten Ertragsraten der einzelnen Aktiva gemacht. Um diesen Ansatz auf Daten anwenden zu können, sind Annahmen über den Zusammenhang von tatsächlichem und gewünschtem Portefeuille sowie über die Erwartungsbildung notwendig. In dieser Arbeit wurden der Stockanpassungsmechanismus und der marginale Anpassungsmechanismus sowie unitäre und rationale Erwartungen näher untersucht.Die Anwendung dieser Modelle auf Daten der österreichischen Versicherungswirtschaft im Zeitraum 1973 bis 1982 zeigt, daß der marginale Anpassungsmechanismus besser geeignet ist, die Enge der heimischen Finanzmärkte wiederzugeben, und daß unitäre Erwartungen rationalen vorzuziehen sind. Im Gegensatz zu Wertpapieren und Forderungen, die zueinander Substitute sind, herrscht bei den Einlagen das Transaktionsmotiv vor, sodaß für diese Position das Portfoliomodell wenig geeignet erscheint. Es ist jedoch nicht auszuschließen, daß die Ergebnisse stark von institutionellen Gegebenheiten beeinflußt worden sind.

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The author is indebted to G. Winckler for helpful discussions.     

投资组合保险—原理及应用

编者按: 自从第一只成功市场化运作的交易所基金(Exchange-Traded Funds,ETFs)--Spiders于1993年产生以来,不到10年的时间,ETFs资产规模迅速膨胀.截止到2002年8月底,全球范围内已有257只ETF,总资产值超过1 242亿美元,成为全球基金业发展中越来越重要的组成部分.     

开放式基金证券组合投资研究

针对开放式基金随时面临投资者的赎回要求这一特点，利用多元统计中的聚类分析和主成分分析，寻找资金进出方便且具有投资价值的股票，建立股票池，然后对股票池中的股票进行市场调研，选出若干只具有投资价值的股票，构建适合开放式基金管理人操作的证券组合投资，最后依公式确定证券组合投资的比例。     

货币危机传染的投资组合模型

传染是近10年货币危机中的一个常见现象。通过构造具有多种风险资产的投资组合模型,可解释造成货币危机传染的多种原因;共同冲击、期望收益率变化、不确定性的增加、风险厌恶程度的变化以及资本损失等,都可以通过影响国际投资者的投资组合而造成货币危机的传染。     

健康与家庭资产选择

本文采用中国居民家庭微观调查数据,运用资产参与和资产分配模型,分别讨论健康状况对居民家庭资产配置行为的影响。研究结果表明:投资者的健康状况不显著影响其参与股票市场和风险资产市场的决定,但影响家庭的股票或风险资产在总财富中的比重,健康状况不佳会导致这两个比重较低,在控制了参保情况或时间展望期后这一影响仍然显著;而投资者风险态度和遗赠动机能够一定程度上解释健康风险的影响。     

Portfolio separation: The analytic case

This paper presents a unified approach to the problem of two-fund portfolio separation under the assumption that the utility function is analytic. It is shown that separation requires that distributions be representable by two homogeneous characteristics.     

Portfolio Choice and Liquidity Constraints*

We study the infinite‐horizon model of household portfolio choice under liquidity constraints and revisit the portfolio specialization puzzle. We show why the puzzle is robust to several model variations, and argue that positive correlation between earnings shocks and stock returns is unlikely to provide an empirically plausible resolution. We find that relatively small fixed costs for stock market entry are sufficient to deter stockholding because, for a plausible range of parameter values, households can achieve desired consumption smoothing with small or zero holdings of stocks. Such costs could arise from informational considerations, sign‐up fees, and investor inertia.     

Portfolio behaviour of selected financial institutions in Canada

It is by now fairly well accepted that financial insititutions in general play role in a market-oriented economy. However,the aim of this paper is more limited. More particularty, it examines the nature of substitutability in the protfolios of selected financial institutions in Canada. The institutions covered are commercial banks, trust and mortgage companies, life insurance companies, and property and casualty companies. These four institutions are by far the most important. The assests covered are, in the most part, dictated by the availability of data. In spite of the obvious significance of the subject, there has been remarkably little work in this area in Canada. The only comprehensive study seems to be that by the Bank of Canada (Clinton and Masson, 1975). However, even this study is confined to the behaviour of commercial banks and the trust and mortgage companies, althouth the treatment of the trust and mortgage companies' portfolio is rather minimal only because just one of its assets is studied. The study covered monthly data until the end of December 1973. The scheme of this paper is as follows. In section I, we briefly discuss the model, the data and the estimation procedures used. In section II the results are given and discussed. The paper concludes with a summary of the main results.     

中小企业品牌战略

品牌经营是企业溢价报酬的重要来源,本篇研究从论述中小企业是否该经营品牌出发,接着研究中小企业品牌战略如何制定,有哪些需要注意的地方,然后进一步举例说明,品牌战略必须要能够分解成战术的执行,以及中小企业品牌经营与大型企业不同之处。