Dynamic Portfolio Choice under Uncertainty about Asset Return Model

The effect of uncertainty about stochastic diffusion model on dynamic portfolio choice of an investor who maximizes utility of terminal portfolio wealth was studied.It applied stochastic control method to obtain the closed-form solution of optimal dynamic portfolio,and used the Bayesian rule to estimate the model parameters to do an empirical study on two different samples of Shanghai Exchange Composite Index.Results show,model uncertainty results in positive or negative hedging demand of portfolio,which depends on investor's attitude toward risk;the effect of model uncertainty is more significant with the increasing of investment horizon,the decreasing of investor's risk-aversion degree,and the decreasing of information;predictability of risky asset return increases its allocation in portfolio,at the same time,the effect of model uncertainty also strengthens.

「など」在复句中的作用及译法

造成日语复句翻译错误的原因,大多是由于对句子之间的关系把握的不准确。更确切地说是对提示复句关系的词语把握的不准确。像「など」作为副助词一般接在名词之后,表示对句中某个成分的"例示"或"提示"之意。然而当「など」接在一个动词句后,与另一个动词句组合成一个复句时,它便呈现出接续助词的特征,成为提示复句关系的关联词了。本文分析了「など」在复句中所提示的语义关系;并且探讨归纳了此类复句的译法。