Incorporating active adjustment into a financing based model of capital structure

The conventional partial adjustment model, which focuses on leverage evolution, has difficulty identifying deliberate capital structure adjustments as it confounds financing decisions with the mechanical autocorrelation of leverage. We propose and estimate a financing-based partial adjustment model that separates the effects of financing decisions on leverage evolution from mechanical evolution. The speed of adjustment (SOA) is firm-specific and stochastic, and active targeting of capital structure has a multiplier effect that depends on the size of financial deficit. Overall, we find expected SOA from active rebalancing (30%) more than doubles what is expected from mechanical mean reversion alone (13%).     

Limitations of portfolio diversification through fat tails of the return Distributions: Some empirical evidence

This study investigates the level of risk due to fat tails of the return distribution and the changes of tail fatness (TF) through portfolio diversification. TF is not eliminated through portfolio diversification, and, interestingly, the positive tail has declining fatness until a certain level is reached, while the negative tail has rising fatness. This indicates that fat tails are highly relevant to common factors on systematic risk and that the relevance of common factors is higher for the negative tail compared to the positive tail. In the portfolio diversification effect, the declining fatness of the positive tail further reduces risk, but the rising fatness of the negative tail does not contribute to this effect. The asymmetry between the fatness of the positive and negative tails in the return distribution corresponds to the asymmetry of the trade-off relationship between loss avoidance and profit sacrifice that is expected as a consequence of portfolio diversification. Investors use portfolio diversification to reduce their risk of suffering high losses, but following this strategy means sacrificing high-profit potential. Our study provides empirical confirmation for the practical limitation of portfolio diversification and explains why investors with diversified portfolios suffer high losses from market crashes. An examination of the Northeast Asian stock markets of China, Japan, Korea, and Taiwan show identical results.     

Investor attention,firm-specific characteristic,and momentum: A case of the Korean stock market

This study examines the sources of negative momentum profits by combining investor attention and the properties of common and firm-specific factors. We choose the Korean stock market as a good case to characterize the negative momentum profits identified in Asia. In both portfolio and stock analyses, a method is devised to generate return data involving the property of each common and firm-specific factor within stock groups by investor attention. This study found significant negative momentum profits within the stock group with high investor attention. This momentum effect is highly dependent on the reversed performance of the past loser portfolio, not the continued performance of the past winner portfolio, and this reversal is strongly attributable to the properties of firm-specific factors, and not those of common factors. These results are robustly consistent regardless of changes in empirical design and the consideration of influence factors, market dynamics, and other stock markets.     

用PERT法求解不确定网络中活动时间参数的改进研究

基于计划评审技术(PERT)中β分布的假设,阐述了常规三时估计方法的不足,提出了相应解决对策,即采用限定概率三时估计法分别建立了β分布和Gamma分布拟合方差最小模型,用微粒群算法求解模型,并且将求解结果与常规三时估计方法进行了对比研究。实例证实,对于不同类型的活动,可以选择合理的分布类型并利用限定概率三时估计法,对各个活动的持续时间服从的分布密度函数进行拟合,从而提高PERT的精度和效率。     

Random matrix application to correlations amongst the volatility of assets

In this paper, we apply tools from random matrix theory (RMT) to estimates of correlations across the volatility of various assets in the S&P 500. The volatility inputs are estimated by modelling price fluctuations as a GARCH(1,1) process. The corresponding volatility correlation matrix is then constructed. It is found that the distribution of a significant number of eigenvalues of the volatility correlation matrix matches with the analytical result from RMT. Furthermore, the empirical estimates of short- and long-range correlations amongst eigenvalues, which are within RMT bounds, match with the analytical results for the Gaussian Orthogonal ensemble of RMT. To understand the information content of the largest eigenvectors, we estimate the contribution of the Global Industry Classification Standard industry groups to each eigenvector. In comparison with eigenvectors of correlation matrix for price fluctuations, only few of the largest eigenvectors of the volatility correlation matrix are dominated by a single industry group. We also study correlations between ‘volatility returns’ and log-volatility to find similar results.     

A continuous model for supply planning of assembly systems with stochastic component procurement times

This paper studies a customized product assembly scenario where some components cannot be stocked due to high component cost and risk. We consider the case where these key components are ordered after a demand has been registered with a promised delivery date. Component lead-times are stochastic and associated distribution function is known in advance. The objective is to determine the ordering time for each component such as to minimize the sum of expected holding and backlogging costs. An approach to solve this problem is proposed and the algorithm is tested on a randomly generated data set.     

机构投资者对证券市场价格波动性的影响——基于Topview数据的实证研究

本文在完整的市场结构数据基础上,研究了市场波动性与机构投资者之间的相互关系。在研究数据方面,我们采用了深度、高频的Topview数据,既避免了前人在研究数据方面的以偏概全,也让我们可以采用更为先进、稳健的实证方法。我们设定了恰当的波动性度量指标,运用了稳健的因果推断方法。并用脉冲响应和方差分解的方法细腻刻画两者之间的相互关系。本文的主要结论是:机构投资者持股比率的波动对上证指数波动有显著的影响,是导致上证指数波动最为主要的原因,法人投资者和个人大户投资者持股比率的变动对上证指数的波动几乎没有影响,机构投资者持股比率波动还会向法人投资者、个人大户投资者持股比率溢出,这些表明在上海证券市场上机构投资者是市场波动的主要来源和主要原因。机构投资者的多元化、坚决推进市场的规范化改革应当成为未来政策关注的重点。     

浅述岩体力学参数监测在隧道施工中的重要性

采用新奥法进行隧道工程施工时,设计单位只能根据监控单位和施工单位反馈的监控数据和隧道开挖揭露情况对设计的合理性进行宏观判断,隧道设计时应把力学计算和实际背景岩体力学参数相结合,才能更科学、经济的按照新奥法的理念完成隧道工程的设计、施工。     

The existence of R&D spillovers: A cost function estimation with random coefficients

This is a study of the effects of R&D spillovers on the cost and production structures of Finnish manufacturing firms. Confidential data on firms is used to estimate a translog cost function system with random coefficients. Although the results suggest that intra-industry spillovers are present in Finnish manufacturing, the findings regarding inter-industry spillovers are inconclusive. The variable cost reduction associated with spillovers is positive, but relatively low. Spillovers reduce the demand for labor but increase the demand for materials. Spillovers also reduce the willingness to pay for capital inputs.     

基于随机久期的商业银行价值优化研究

通过分析商业银行价值的本质,比较企业价值的理论及评估方法和讨论商业银行的利率风险及度量方法,选择了收益法以银行的净现金流量为研究口径来分析银行净资产价值的优化问题。定义了金融工具基于连续时点的随机久期,应用随机久期方法管理银行的利率风险,通过久期缺口分析,证明了银行净资产价值与利率之间的关系,得出了银行价值的优化路径,即通过平衡现金流、风险及持续经营三者之间的关系,达到商业银行价值的最佳平衡状态。最后,分析了研究中的局限性以及值得深入探讨的工作方向。