Basel III Capital Requirements and Lending: The Case of the D-SIB Capital Buffer in Thailand

This study attempts to measure the endogeneity-prone effects of the implementation of the domestic systemically important bank (D-SIB) capital buffer in Thailand by creating a synthetic control for each D-SIB. The main findings suggest that the D-SIBs responded to the D-SIB capital buffer differently, depending on the relative size of the portfolios with higher risk weights. Specifically, the D-SIB with the highest proportion of business loans in its portfolio decreased lending growth more than the other two D-SIBs, whereas the D-SIB with the highest proportion of retail loans did not significantly decrease lending growth. In addition, the state-owned commercial bank behaved differently from other banks such that synthetic controls cannot be created to replicate the unique behavior. While this study finds no significant effects on capital and risk-weighted assets in the short run, it cannot rule out the possibility of the D-SIBs raising more capital in the longer run.