CIRJE-F-105. Miwa, Yoshiro and J. Mark Ramseyer, "Does Ownership Matter? Evidence from the Zaibatsu Dissolution Program", February 2001.

In 1985, Demsetz & Lehn argued both that the optimal corporate ownership structure was firm-specific, and that market competition would drive firms toward that optimum. Because ownership was endogenous to expected performance, they cautioned, any regression of profitability on ownership patterns should yield insignificant results. To test the Demsetz- Lehn hypothesis, we use the zaibatsu dissolution program from late-1940s Japan as an exogenous shock to the pre -war ownership equilibrium. Through that program, the U.S. -run occupation removed the more prominent shareholders from many of the most successful Japanese companies. By focusing on the effect the program had on profitability and on the way firms responded to the program, we accomplish two goals: (a) we avoid the endogeneity problem that has plagued much of the other research on the subject, and (b) we clarify the equilibrating dynamics by which competitive markets move firms toward their optimal ownership structure. With a sample of 637 Japanese firms for 1953 and 710 for 1958, we confirm the equilibrating mechanism behind Demsetz-Lehn: between 1953 and 1958, the ex- zaibatsu firms did significantly reconcentrate their ownership structure. As of 1953, the unlisted ex-zaibatsu and new firms still had not yet been able to negotiate the transactions necessary to approach their optimum ownership structures, and even the listed firms had not fully undone the effect of the occupation-induced changes on managerial practices. By 1958 they had, and the earlier correlation between profitability and ownership disappeared. By then, firm profitability showed no correlation with ownership, whether under linear, quadratic, or piecewise specifications. We further find no evidence that ex- zaibatsu firms sought to strengthen their ties to banks over 1953 - 58.