Ex ante, ex post risk and bank capital ratios: an empirical investigation

Purpose - The purpose of this study is to investigate the impact of leverage, regulatory capital and tier-I capital ratios on the ex ante and ex post risk of Japanese banks. Design/methodology/approach - To test the hypotheses, the authors have implemented a panel of 507 commercial and cooperative banks of Japan over the period extending from 2001 to 2020, using a two-step system Generalized Method of Moments (GMM) framework. Findings - The overall sample banks' results show that the impact of leverage, regulatory capital and tier-I capital ratios on ex ante and ex post risk is positive. The findings reveal that the effects of regulatory and tier-I capital ratios on ex post risk are negative (positive) for commercial (cooperative) banks, high-liquid, low-liquid and high-growth banks in Japan. In addition, the regulatory capital ratio is more beneficial for risk due to its power to absorb losses. The lagged coefficient indicates that banks require more time to adjust their ex post and ex ante risk during crisis period than during normal economic conditions. Practical implications - The heterogeneity in results has practical implications for regulators, policymakers and bank managers in formulating the capital requirement guidelines with respect to ex ante and ex post risk across different categories and characteristics of banks. Originality/value - To the best of the authors' knowledge, this is the first study investigating the impact of leverage, regulatory capital and tier-I capital ratios on the ex ante and ex-post risk of Japanese commercial and cooperative banks over the period from 2001 to 2020. The insights into the impact of leverage, regulatory capital and tier-I capital ratios on the ex ante and ex post risk of well-capitalized, under-capitalized, high and low-liquid banks are new in the context of Japan.