企业IPO对同行业上市公司的影响:竞争效应还是信息溢出效应?——基于动态产品市场竞争的微分博弈模型与实证研究

从理论和实证两个方面, 研究企业IPO对同行业上市公司的均衡价值及产品市场差异化竞争的影响.在已有研究基础上加入信息溢出效应, 基于动态产品市场竞争构建了一个微分博弈模型, 模型结果表明:IPO后在位上市公司相对行业竞争力低于临界值时, 其均衡价值减少; IPO前其相对行业竞争力高于临界值时, 其均衡价值增加.采用沪深A股、中小板与创业板的市场数据, 运用非线性最小二乘法估计动态结构化模型参数, 实证研究IPO对产品市场异质化竞争倾向的影响.实证结果表明, IPO后行业消费者忠诚度提高, 产品市场竞争倾向趋于异质化竞争, 在位上市公司的市场份额利润转化率提高.这说明我国IPO竞争效应占主导地位, 企业IPO对在位上市公司构成威胁, 在位上市公司采用差异化的产品竞争策略提高竞争力和盈利能力.

Competition effect or information spillover effect of IPO on peer listed firms:A differential game model and empirical study based on dynamic product market competition

From the theoretical and empirical aspects, this paper studies the influences of IPO on the equilibrium value and the differentiated product market competition of peer listed companies. Improving existing studies by introducing the information spillover effect, a differential game model is developed based on dynamic product market competition. Our model shows that the equilibrium value decreases if a firm''s relative competitiveness is less than the critical value after IPO, while its equilibrium value increases if its relative competitiveness is greater than the critical value before IPO. Based on the data of the small and medium plates, GEM, and all listed A shares, the differentiated product market competition after IPO is studied by using nonlinear least squares to estimate dynamic structured model parameters. The empirical results show that firms after IPO tend to enjoy higher consumer loyalties, that the product market competition tends to be heterogeneous, and that more market shares are converted into profits, which suggests that the competition effect of IPO is dominant. Moreover, IPO poses a threat to listed companies, and forces them to adopt differentiated product competition strategies to improve their competitiveness and profitability.