To create this dataset we collected the directorship data of the 200 largest nonfinancial firms and the 50 largest financial firms, in terms of total assets, for the years 1911, 1928, 1937, 1957, 1973, 1982, 1992, 1998 and 2009.
In order to obtain the asset data and information on directors and auditors for pre-war Japan, we used a series of company directories compiled by a major securities company, Osakaya Shoten (Kabushiki Nenkan ). Because this source focuses on those companies with shares actively traded on the stock market, we supplemented the data for companies with closed ownership, such as the companies affiliated to major zaibatsu, with other sources, including Ginko Kaisha Yoroku by Tokyo Koshinjo, a credit bureau. With respect to the post-war period, the principal data source is a series of handbooks on the so-called keiretsu business groups by Toyo Keizai Shinposha (Kigyo Keiretsu Soran). As this source only covers the period from 1972 to 1999, we obtained the data for 1957 from Jojogaisha Soran by the Tokyo Stock Exchange, while the data for 2009 were collected from the annual reports of individual companies. Using the dataset constructed from those sources, we identify the 200 largest non-financial firms and the 50 largest financial firms, in terms of total assets, for the aforementioned benchmark years. Then, for these firms, we construct a database of directors and auditors in order to explore the features and evolutions of Japanese corporate networks.
