中小企业融资约束对R&D投入的影响分析——基于门限效应模型

在对国内外IPO定价有效性相关理论和文献进行梳理和归纳基础上，确定IPO抑价程度作为衡量新股定价有效性评价标准，并将其设为模型的被解释变量；另外，选取新股IPO中的募集资金净额、首发市盈率、上市市盈率、上市换手率、发行至上市期间市场回报率等作为解释变量。运用多元线性回归方法构建模型，样本数据来自于2005年-2016年A股市场IPO企业。实证检验结果表明，IPO抑价率与募集资金净额、发行市盈率和发行至上市期间市场回报率呈负相关关系，与上市市盈率、上市换手率呈正相关关系，揭示出我国A股市场IPO抑价现象是由一级市场与二级市场综合影响所致的。据此，提出相应的政策建议。

Analysis of the Influencing Factors of IPO Pricing Efficiency in China's Securities Markets

On the basis of combing and summarizing the theories and literatures related to IPO pricing effectiveness at home and abroad, this paper determines the degree of IPO underpricing as the evaluation standard to measure the effectiveness of IPO pricing, and sets it as the explained variable of the model. In addition, the net amount of funds raised in IPO, initial p/e ratio, p/e ratio, turnover rate and market return rate from issuance to listing are selected as explanatory variables. Multiple linear regression method was used to build the model. Sample data were collected from IPO companies in A-share market from 2005 to 2016.The empirical test results show that the IPO underpricing rate is negatively correlated with the net amount of funds raised, the p/e ratio of issuance and the market return rate between issuance and listing, and positively correlated with the p/e ratio and turnover rate of listing, revealing that the IPO underpricing phenomenon in China''s a-share market is caused by the comprehensive influence of the primary market and secondary market. Accordingly, put forward corresponding policy proposal.