Host: The Japanese Society for Artificial Intelligence
Name : The 32nd Annual Conference of the Japanese Society for Artificial Intelligence, 2018
Number : 32
Location : [in Japanese]
Date : June 05, 2018 - June 08, 2018
Recently, some empirical studies argue that ``horizontal shareholding'' (or ``common ownership'') lessen competition among companies and prevent growth of an industry. Especially, horizontal shareholding by index funds occupy more weights of lists of shareholders and became a subject of greater debate. In this study, I built an artificial market mode, a kind of agent based model, and investigated an effect of increasing of horizontal shareholding by index funds to competitions and market prices. Our result shows that even when holding ratio of index funds is not so much they lessen competition. Moreover, when value of a company beating competition grow, its market price grow more than the company value (overshoot) and become over valued, then shareholders who encourage competition decrease and the company lose competition power. On the other hand, when value of a company losing competition drop, its market price fall deeper than the company value (overshoot) and become under valued, then shareholders who encourage competition increase and the company gains competition power. My simulation result indicated such mechanism balances competition powers among corporates. Growing index funds may possibly weaken the balancing mechanize.
