戦時期の企業金融

―経済新体制確立要綱前後で株主価値や企業価値は変化したのか？―

抄録

This study analyzes the changes in shareholder value and corporate value following the approval of the Gist for the Establishment of the New Economic System (Keizai Shintaisei Kakuritsu Yoko) by the Japanese Cabinet in December 1940. Previous research on Japanese corporate finance during the war period lacks sufficient quantitative analysis of financing policies, primarily due to the difficulty of acquiring long-term time series data on corporate finance and stock investment performance. As a result, quantitative research in this area has been limited.

Nevertheless, understanding corporate finance during the war period is essential for contextualizing the history of corporate governance in Japan. This study utilizes Modigliani and Miller’s (1958) framework to calculate and quantitatively analyze capital structure, as well as the Capital Asset Pricing Model to evaluate shareholder and corporate value.

The key findings of this long-term time series analysis on corporate finance and stock investment performance are summarized as follows:

1. The equity spread, calculated by subtracting the cost of capital from ROE, peaked in the first half of 1937, and then deteriorated by the end of the war, indicating a significant decline in shareholder value.

2 . The EVA Spread, calculated by subtracting WACC from ROIC, exceeded the equity spread, suggesting that corporate value was maintained due to a sharp increase in the debt funding ratio. However, after the enactment of the Munitions Corporation Law in October 1943, the negative EVA spread widened, confirming a decline in corporate value. This may be attributed to ineffective financial monitoring by institutions, which led to a sharp rise in debt ratios and the potential occurrence of soft budget constraints.

3 . Corporate governance in the 1940s did not undergo a fundamental shift with the introduction of the New Economic System. Instead, changes occurred gradually, with a notable turning point before and after the enactment of the Munitions Corporation Law.

4 . By the end of the war, while the debt funding ratio had increased, the involvement of financial institutions diminished due to the deterioration of corporate value. This suggests that wartime corporate finance was not continuous with the post-war corporate finance system, which centered on financial institutions.