基于动态面板数据的政治关联和非效率投资

以2005--2010年中国沪深两市的A股上市公司为样本进行实证研究，第一阶段采用动态面板数据模型中的GMM估计方法计量上市公司的非效率投资行为，并将该结果代人第二阶段建立非效率投资与政治关联多元回归模型。同时对样本公司进行分类以检验政治关联在不同产权性质上市公司中的作用效果。研究结果表明：政治关联强化了公司的过度投资行为，抑制投资不足行为；国有产权上市公司的政治关联显著地促进过度投资并抑制投资不足行为，而私有产权上市公司只是显著地促进过度投资；相对中央政府，地方政府控制的国有上市公司政治关联作用程度更大。

Political Connection and Inefficient Investment Based on Dynamic Panel Data

The listed companies in the years 2005 -2010 were empirically studied. In the first step of measurement of ineffi- cient investment, GMM estimate was made based on the dynamic panel data to get the result which will be used in the next step; in the second step, regression model was constructed to test the effect of political connection on inefficient investments. Further- more, the effects of political connection in listed companies of different property rights were analyzed. With the study, it was found that： political connection strengthens listed company＇s over- investment behavior and restrains their low -investment be- havior; political connection in the state- own companies strengthens over- investment behavior and restrain their low -invest- ment behavior significantly, but this significance only survives in the over - investment behavior of private companies ; political connection functions are greater in those companies controlled by the local government than in those controlled by the central gov- ernment.