风险分散与中国混合型基本养老保险制度改革研究

本文从参保人养老投资风险分散角度研究混合型基本养老保险制度设计。通过构建一个两期消费模型,综合考虑参保人所面临的人口结构、工资增长率、养老基金投资等风险因素,本文研究了混合型基本养老保险制度中现收现付制与基金积累制的最优比例,并利用中国数据进行了测算与敏感性分析。研究发现:引入小规模个人账户基金积累制可以分散人口老龄化给现收现付制所带来的风险,中国实行混合型基本养老保险制度有其合理性;但如果要维持40%～45%的养老金替代率水平,中国基本养老保险制度的财务可持续性会面临较大挑战。     

The long-run performance of diversifying firms

The corporate diversification literature presents a puzzle. Short-horizon event studies report positive abnormal returns around the announcement of a diversifying event, while studies that examine diversified firms find evidence that diversified firms are worth less than specialized firms (a diversification discount). If diversification is value destroying, perhaps the destruction occurs over longer periods than have been previously tested. This paper tests the hypothesis that diversifying firms have negative long-run abnormal performance following diversification by examining a sample of specialized firms that have a diversifying event from 1978 through 1998. The firms are tracked for up to five years past their diversification year. There is evidence that value is destroyed for small firms that diversify but enhanced for larger firms that diversify.

我国上市公司的多元化战略与公司绩效

本文以2004年深沪两市的696家非金融公司作为样本,通过建立有效的多元化经营指标,考察了中国上市公司多元化战略与其绩效(CROA)的关系。实证研究表明,多元化有一定的正面效应,即能够降低公司经营风险,但是从整体上来看,多元化的成本仍然大于收益,导致多元化程度与公司绩效负相关。这一实证结果与多元化给企业带来巨大成本的理论一致。     

Does corporate international diversification destroy value? Evidence from cross-border mergers and acquisitions

This paper investigates the valuation effects of corporate international diversification by examining cross-border mergers and acquisitions of US acquirers over the period 1990–2000. We find that, on average, acquisitions of “fairly valued” foreign business units do not lead to value discounts. In contrast, unrelated cross-border acquisitions result in a significant diversification discount of about 24% after accounting for the valuation of foreign targets. Furthermore, significant wealth gains accrue to foreign target shareholders regardless of the type of acquisition. Overall, our results suggest that international diversification does not destroy value while industrial diversification leads to discounts even after controlling for the pre-acquisition value of the target.     

Maximizing an equity portfolio excess growth rate: a new form of smart beta strategy?

It has been claimed that, for dynamic investment strategies, the simple act of rebalancing a portfolio can be a source of additional performance, sometimes referred to as the volatility pumping effect or the diversification bonus because volatility and diversification turn out to be key drivers of the portfolio performance. Stochastic portfolio theory suggests that the portfolio excess growth rate, defined as the difference between the portfolio expected growth rate and the weighted-average expected growth rate of the assets in the portfolio, is an important component of this additional performance (see Fernholz [Stochastic Portfolio Theory, 2002 (Springer)]). In this context, one might wonder whether maximizing a portfolio excess growth rate would lead to an improvement in the portfolio performance or risk-adjusted performance. This paper provides a thorough empirical analysis of the maximization of an equity portfolio excess growth rate in a portfolio construction context for individual stocks. In out-of-sample empirical tests conducted on individual stocks from 4 different regions (US, UK, Eurozone and Japan), we find that portfolios that maximize the excess growth rate are characterized by a strong negative exposure to the low volatility factor and a higher than 1 exposure to the market factor, implying that such portfolios are attractive alternatives to competing smart portfolios in markets where the low volatility anomaly does not hold (e.g. in the UK, or in rising interest rate scenarios) or in bull market environments.     

企业多元化经营问题初探

当今,很多企业选择以多元化经营作为自身做大做强的战略。然而根据不完全统计的结果,世界上企业的多元化战略75％是失败的,由于多元化导致企业失败的例子比比皆是。多元化本身没有对错,关键是如何去经营。文中从多元化战略的选择动机和优劣势分析入手,总结影响多元化经营成败的因素,从而希望企业在选择实施多元化战略的过程中能够取得成功。     

Ownership structure and the diversification and performance of publicly-listed companies in China

The growth and heightened competitiveness of listed companies in China share several central features. These include the gradual transition of state-owned assets to private investors, a rapid pace of product diversification, and impending rapid growth into international markets. In this article, we focus on measuring and identifying the implications of the ownership structure and diversification strategy of listed companies in China. We highlight recent developments in the ownership transition of China's companies, and point to an ownership classification system that can better identify and address differences in the motivations, strategies, and performance of these companies.     

Effect of diversification on firm performance: Application of the entropy measure

This study investigated the effects of diversification on firm performance in the restaurant industry. In prior studies, the theoretical rationales and empirical results appeared to contradict each other. These contradictory results may be due to factors such as industry-specific characteristics or a linear understanding of the relationship between diversification strategies and firm performance. Thus, this study suggested a non-linear hypothesis based on the costs and benefits of diversification strategies with businesses categorized based on their level of diversification. The results of this study showed that restaurant firms do not benefit from a low level of related diversification. This study also found that when restaurant firms are involved in both related and unrelated businesses, the optimal mixed ratio of diversification is approximately half and half. More detailed results, as well as academic and practical implications, are discussed in this paper.     

透视春兰多元化

本文通过深入剖析春兰集团多元化三个台阶的发展状况，归纳了企业多元化应具有的先决条件。希望能够使企业充分认识多元化优缺点，从而使企业能够避免落入盲目多元化的陷阱。