Research on the Governance Effect of the Ownership Structure on the Over-investment Behavior

——Based on the Theoretical and Empirical Evidence of the Balance of Power Brought by Heterogeneous Equity in the Mixed Ownership Enterprises YIN Yu-pin

（Beijing Wuzi University，Beijing101149，China）

Abstract：Under the background of mixed ownership reform，the mix of state- owned and private capital will be realized through investment；and this process will definitely increase the risk of over- investment. Sound corporate governance structure may play the adjustment role to over-investment，which will limit the behavior of over-investment. According to the hypothesis of stockholder relation，if stockholders with balance of power play their role in supervising controlling stockholders，this risk will be reduced；and if they plot together to exploit small and medium stockholders，this risk will be increased. Because of the precondition of state-owned and private capital，stockholder relation will be influenced by the nature of capital. It is found that， when the equity percentage held by controlling stockholders is from 10% to 50% ，if the nature of controlling stockholders and stockholders with balance of power is heterogeneous，the second large stockholders’variable concerning balance of power can not play its role in supervising over- investment；and if the nature of them is the same，the heterogeneous interests behavior among stockholders will lead to the effect of balance of power when they are all state-owned capital，which will demonstrated as “the same，but no conspiracy”，and there is no significant effect of balance of power on over- investment when they are all private capital，which will increase the possibility of conspiracy.

Key words：heterogeneous equity；equity balance of power；over-investment；mixed ownership