The researchers looked at how changes in bank regulations in Japan affected bank competition and risk-taking. They found that when capital requirements were relaxed, banks became more willing to take risks, especially in terms of loan growth and interest rates. The study showed that competition among banks led to higher levels of risk-taking, and that the impact of this competition on risk-taking was influenced by changes in regulations. Specifically, banks that were more active within Japan saw different effects compared to those operating internationally.