Empirical Examination of Corporate Governance Functions Performed by the Main Bank and the Equity Ownership Structure in Japan

1.我们利用1985年至1998年的财务和股权数据，估计了东京证券交易所上市公司的托宾q值。我们把持有的股票和土地的价值换算成市场价值。特别是，我们通过考察20世纪90年代土地税隐含的土地市场价值来检验我们估计的有效性。使用相同的数据集，我们实证检验了主银行和交叉持股对托宾q测量的企业价值的影响。结果表明，虽然主银行关系在80年代由于其垄断力量而降低了企业价值，但其影响在90年代变得中性，反映了主银行的垄断力量减弱。我们还发现，由于管理层的固守，相互持股倾向于降低企业价值，而单向持股倾向于提高企业价值，因为管理层的监督增加。我们进一步研究了企业盈利能力与主银行之间的关系。实证结果表明，主银行关系降低了企业的盈利能力，表明持有成本的存在。我们还发现，多元主银行关系可以降低主银行关系对企业盈利能力的负面影响。我们研究了不同类型投资者（个人、外国人、交叉持股和机构投资者）的证券投资行为。我们发现，在20世纪90年代，机构投资者和公司投资者都倾向于过度投资于财务状况不佳的公司。我们认为，这表明他们可能会投资，以拯救弱势的经联成员公司。

1.We estimated Tobin's q for individual companies listed on the Tokyo Stock Exchange by using the financial and equity data from 1985 to 1998. We converted the value of stock holding and land to their market value. Especially, we checked the validity of our estimates by examining the market value of land implied by the land tax in the 1990's.2.Using the same dataset, we empirically examined how the main bank and cross shareholding affected the firm value measured by Tobin's q. The results show that while the main bank relation lowers firm value due to its monopolistic power in the 1980's, its influence becomes neutral in the 1990's, reflecting the main bank's weakened monopolistic power. We also find that while mutual shareholding tends to lower firm value because of management entrenchment, one-way shareholding tends to increase firm value due to increased monitoring of managers.3.We further investigated the relationship between the firm profitability and main bank. Our empirical results show that the main bank relation lowers firm profitability, indicating the existence of hold-up costs. We also find that multiple main bank relationships can reduce the negative effect of the main bank relation on the firm profitability.4.We examined portfolio investment behavior across different types of investors (individuals, foreigners, cross shareholding, and institutional investors). We find that in the 1990's both institutional and corporate investors tend to over-invest in financially weak firms. We interpret this as indicating that they may invest in order to rescue weak keiretsu member firms.