Investment is of crucial importance for business fluctuations and economic growth.The global financial crisis brought great damages on entity economies of many countries,which triggers the unveiling of a series of economic stimulus programs including many tax policies to promote investment.Based on analyzing the tax policies promoting investment in the context of financial crisis in main countries globally,this paper discusses the influence of tax policy on enterprise investment,which can be used as a reference to adjust the tax policy for enhancing economic growth.

Saving is a typical inter-temporal choice behavior. Apart from the rationality axiom in traditional economics, self-control hypothesis in psychological economics presents a better explanation of intertemporal behaviors. After reviewing the related literatures in saving theory, the paper draw out the mathematical forms of self-control in behavioral life cycle model. Based on the Chinese householder saving development and abnormal event in recent years, the paper makes use of temptation and the mental cost elements in self-control hypothesis, analyzes the impact of interest tax levied in China on the household savings deposits and its reasons, explains the abnormal event of deposit around that year.