焦点企业知识存量对联盟组合分裂断层的影响：知识转移效率的中介作用

运用断层理论,从知识获取和关系治理角度,分析焦点企业知识存量如何影响联盟组合分裂断层及分裂断层形成机理。基于焦点企业知识存量、分裂断层、知识转移效率、情景嵌入性之间的关系理论模型框架,认为焦点企业知识存量能够影响联盟组合分裂断层,其中,知识转移效率在这一过程中发挥中介效应,情景嵌入性发挥调节效应。结果发现：焦点企业知识存量与分裂断层之间存在显著负相关关系;知识转移效率能够部分中介焦点企业知识存量与分裂断层之间的关系;情景嵌入性能够正向调节焦点企业知识存量与知识转移效率之间的关系。     

Risk sharing and counter-cyclical variation in market correlations

I present a consumption-based dynamic asset pricing model in which international market correlations vary counter-cyclically over time. The driving force in the model is the time-varying effective risk aversion induced by external habit formation. Market returns are driven by fundamental outputs and discount rates. When risk aversion is high, the effect of discount rates on market returns rises with the market price of risk. To the extent that countries share risk, the cross-country correlation of discount rates exceeds the cross-country correlation of fundamental outputs. In bad times, market correlations rise as returns are mostly driven by discount rates. Thus, consistent with the empirical evidence, periods of high risk aversion are associated with high market correlations and high market volatility. After calibration, my model is consistent with the observed variation in market correlations, as well as other features of asset prices including the equity premium and market volatility.     

Testing time-homogeneity of rating transitions after origination of debt

When modelling rating transitions as continuous-time Markov processes, in practice, time-homogeneity is a common assumption, yet restrictive, in order to reduce the complexity of the model. This paper investigates whether rating transition probabilities change after the origination of debt. Accordingly, we develop a likelihood-ratio test for the hypothesis of time-homogeneity. The alternative is a step function of transition intensities. The test rejects time-homogeneity for rating transitions observed over 7 years in a real corporate portfolio. Especially 1-year transition probabilities increase over the first year after origination. This time effect suggests that banks should manage their credit portfolios with respect to the age of debt.      

Portfolio optimization based on GARCH-EVT-Copula forecasting models

This study uses GARCH-EVT-copula and ARMA-GARCH-EVT-copula models to perform out-of-sample forecasts and simulate one-day-ahead returns for ten stock indexes. We construct optimal portfolios based on the global minimum variance (GMV), minimum conditional value-at-risk (Min-CVaR) and certainty equivalence tangency (CET) criteria, and model the dependence structure between stock market returns by employing elliptical (Student-$t$ and Gaussian) and Archimedean (Clayton, Frank and Gumbel) copulas. We analyze the performances of 288 risk modeling portfolio strategies using out-of-sample back-testing. Our main finding is that the CET portfolio, based on ARMA-GARCH-EVT-copula forecasts, outperforms the benchmark portfolio based on historical returns. The regression analyses show that GARCH-EVT forecasting models, which use Gaussian or Student-$t$ copulas, are best at reducing the portfolio risk.     

日元升值预期下日本国际投资策略与特点

1971年至1995年期间,日元处于急剧升值阶段,在此之后的十多年里日元升跌互见,整体波动缓和,2008年初以来日元持续升值。在日元升值预期的作用下,自20世纪90年代以来,日本加大了海外直接投资的力度,近2/3的资金流向了经济比较发达的国家和地区。与海外直接投资相比,日本的证券投资规模较大,占海外资产总额的近五成,其投资组合策略注重汇率风险管理,始终保持了一贯的连续性,重视资产的安全性和回报率。日本也加快了以其他方式向海外输出资本的步伐,按照国际收支状况的统计口径,这些投资包括对外贷款、贸易信贷、货币及存款和其他资产,其规模仅次于海外证券投资。研究表明,日本的海外投资区域分布和币种选择体现了分散投资、降低风险的特点,也在较大程度上降低了汇率风险。     

流动性、生命周期与投资组合相异性——中国投资者行为调查实证分析

本文采用Probit和Tobit模型对中国居民的股票市场参与和投资组合的影响因素进行了分析,主要有以下的实证发现:首先,不流动性资产特别是房地产的投资显著影响了投资者的股票市场参与和投资组合,而且影响以“替代”效应或者说“挤出”效应为主。其次,投资者在进行投资组合时极少利用股票市场对其未来现金流所承担的风险进行对冲,也就是说,中国居民投资的“生命周期效应”不明显;第三,中国居民投资的“财富效应”非常显著。财富的增加既增加了居民参与股票市场的概率,也增加了居民参与股票市场的深度。     

国有银行与股份制银行资产组合配置的差异研究

商业银行国有产权与银行业绩表现的关系,近来成为一个热点话题。但是,很少有文章讨论银行国有产权与银行谨慎经营行为的关系。本文依据银行资产组合配置比率指标,研究了中国国有商业银行与股份制银行在谨慎行为方面的差异。实证结论表明:股份制银行比国有银行经营更为谨慎;国有银行由于管理与经营机制的改革正变得越来越谨慎。     

Estimating the equity premium

Accurate estimation of the equity premium (the expected difference between the returns to a well-diversified stock market portfolio and a riskfree asset) is of central importance in many applications of finance theory including project appraisal and portfolio selection. The standard approach is to take the average observed excess returns to the market over some recent time period (sometimes referred to as the ex post equity premium) and apply this as an unbiased estimate of the ex ante equity premium. The paper reviews the problems associated with such an approach and contrasts it with alternative theoretical techniques.     

The power of market mood — Evidence from an emerging market

This article focuses on investor behavior and, consequently, the mood in the market. By using a self-organizing network we develop a model which tries to capture the market mood and serves as an indicator of the reasonableness of selling or purchasing securities. In this sense, the final result of this model is the same as in the model-type prediction of future stock prices, with the only exception being that one is not required to know the concrete future values of the selected security. This will indirectly support the hypothesis that psychological factors are an important (if not key) market driving force.     

Growth Optimal Investment Strategy: The Impact of Reallocation Frequency and Heavy Tails

The strategy to maximize the long‐term growth rate of final wealth (maximum expected log strategy, maximum geometric mean strategy, Kelly criterion) is based on probability theoretic underpinnings and has asymptotic optimality properties. This article reviews the allocation of wealth in a two‐asset economy with one risky asset and a risk‐free asset. It is also shown that the optimal fraction to be invested in the risky asset (i) depends on the length of the basic return period and (ii) is lower for heavy‐tailed log returns than for light‐tailed log returns.