An Application of Self-Organizing Maps to Financial Structure Analysis of Keiretsu versus Non-Keiretsu Firms in Japan

It has been argued that keiretsu in Japan allows its member firms to maintain a financial structure different from that of non-keiretsu member firms. In this paper, we use two different types of financial statement ratio analysis techniques to discover whether Kohonen's self-organizing map (SOM) is able to uncover the differences in financial structures between keiretsu and non-keiretsu firms: ad hoc financial ratios and valuation-based financial ratios. We have found some evidence that SOM enables both financial analysis techniques to recognize different financial structures between the two groups of the firms. Implications of this finding for investment decisions have been discussed.