Tail dependence risk exposure and diversification potential of Islamic and conventional banks

This paper undertakes a rolling window comparative analysis of risks for portfolios consisting of GCC Islamic and conventional bank indices. We draw our empirical results by employing canonical, drawable and regular vine copula models, as well as by implementing a portfolio optimization method with a conditional Value-at-Risk constraint. We find evidence of higher riskiness in the group of Islamic banks relative to the group of conventional banks across each of the financial rolling window scenarios under consideration. Specifically, a greater negative (nonlinear) tail asymmetric dependence is observed in the pairs of Islamic banks’ relationships. The results also show that the optimal portfolio model supports a clear preference towards the group of conventional banks in regard to risk minimization and diversification benefits.     

Cattle as a consistently resilient agricultural commodity

This study compares a range of agricultural commodities over periods of varying economic circumstances. These commodities are examined over three categories, including returns, risk, and contribution to portfolio optimisation. Consistency in these categories is determined over four equal three-year stages which comprise pre-GFC (Global Financial Crisis), GFC, post-GFC and post-post GFC. To demonstrate resilience in the most extreme circumstances, the study uses Conditional Value at Risk (CVaR), which measures extreme risk in the tail of a distribution, as the risk measure and risk-return optimiser. The study thus provides a unique and comprehensive extreme-risk based focus which identifies and ranks the consistency of performance of agricultural commodities over a range of criteria and conditions. Cattle commodities consistently demonstrate the strongest overall performance in the categories examined.     

Firm size and types of innovation

We propose a general theory of innovation that illustrates the relative benefits of performing process versus product R&D when firm size is endogenous. A firm's size, scope, and R&D portfolio are shown to reflect the same underlying characteristic of the firm, namely manufacturing efficiency. We demonstrate that efficient firms become larger, have greater scope, and perform more of both process and product R&D. In light of decreasing returns to R&D, this implies small firms obtain more product innovations per dollar of R&D than large firms, which is consistent with evidence we present that small firms are more innovative than large firms as they obtain more patent counts and citations per dollar of R&D.     

Implementing technology roadmapping with supplier selection for semiconductor manufacturing companies

The rapid pace of technological innovation in the semiconductor manufacturing industry has necessitated the acquisition of competitive advantage from strategic technology planning. The vital requisite for this is well-timed investment including the replacement of old equipment with advanced new equipment. In such investment, selecting the appropriate semiconductor manufacturing equipment from the appropriate supplier is a key factor for successful technology planning. Therefore, equipment supplier selection should be taken into account in the technology planning of semiconductor manufacturing companies. One of the most widely used tools for technology planning is the technology roadmap (TRM). However, conventional TRMs have not considered the task of supplier selection. To address this limitation, this study proposes an extended, four-layered TRM that adds the layer of equipment supplier to the conventional layers of market, product, and technology. The equipment suppliers to be included in the new layer are selected from the supplier portfolio matrix composed of two performance axes: supplier performance and equipment performance. The candidates of equipment suppliers are placed on the supplier portfolio matrix according to the values of two axes determined by evaluation using the analytic hierarchy process (AHP). The proposed TRM is expected to be useful for technology planning by adding a consideration for equipment supplier selection in semiconductor manufacturing companies.     

On the Endogeneity of the Mean-Variance Efficient Frontier

The endogeneity of the efficient frontier in the mean-variance model of portfolio selection is commonly obscured in the portfolio selection literature and in widely used textbooks. The authors demonstrate this endogeneity and discuss the impact of parameter changes on the mean-variance efficient frontier and on the beta coefficients of individual assets.     

股票资产组合VaR研究基于混合D藤Copula模型

本文在对上证市场五种股票资产组合的风险分析中以VaR作为风险度量指标,采用基于Pair Copula高维建模理论的混合D藤Copula模型,建立了反应多个资产组合相关结构的联合分布模型。该模型对传统D藤Copula建模方法作了进一步的改进,通过一定的选择标准,确定了D藤中每个Pair Copula函数的最优函数族,这样使得所建立的模型不仅考虑到了资产维数的影响,而且还能捕捉到组合内部因子间相关结构的差异性,从而改进后的模型能更好地描述资产组合的相关结构,并且能更精确地反映资产组合收益的实际分布。最后,以混合D藤Copula模型为基础,利用Monte Carlo方法计算了上证市场五种股票资产组合的VaR,并通过实证研究进一步证明了该模型的有效性。     

社保基金股票投资组合的行业偏好初探

全国社会保障基金是价值型投资者,行业配置对其具有重要意义。通过考察2008年末全国社会保障基金的股票委托投资组合在行业配置上总体的分布情况,分析出该基金的受托人在股票市场处于周期性底部区域时偏好投资于周期型行业,尤其是传播与文化产业,交通运输与仓储业,电力、煤气及水的生产和供应业,以及房地产业,并得出了在这一时段受托人的行业配置风格与该基金的投资原则和该基金作为价值型机构投资者的定位相符的结论。     

中国房地产财富的担保与非对称性效应研究

根据消费生命周期理论假说可知,在消费者远见和信贷市场完备条件下,只有预期外的冲击才会对消费产生影响,房地产财富不具有担保效应;从消费者行为金融理论可知,盈利和损失对消费者的影响是不对称的。随着我国房地产在国民经济中的作用日益显著,房地产财富效应日益凸现,为了分析我国房地产市场是否具有担保和非对称性效应,对我国房地产财富和消费进行经验研究。研究发现我国房地产财富对消费的影响不支持恒久生命周期假说,基于房地产财富的消费市场存在流动性约束及"近视"现象,房地产财富对消费具有较为显著的非对称效应和担保效应。     

风险资本能改善风险投资企业治理效率吗?——一个盈余管理视角

从风险资本积极投资者的角度研究了风险资本投资企业的公司治理结构对风险投资企业创业板上市时盈余管理的影响。实证结果表明,风险投资企业公司治理结构中仅有董事会规模对公司盈余管理有抑制作用;独立董事比例、风险资本董事比例、监事会规模和外部监事比例对公司盈余管理都没有显著影响。同时,董事会、监事会持股比例,CEO持股比例对公司上市时盈余管理也没有显著影响。创业板上市风险投资企业的盈余管理程度主要受公司规模、财务杠杆比例以及公司行业特征影响。