Strategic imperatives: green bond integration and digital economic infrastructure for Japan's energy transitions

Abstract This study conducts empirical research to analyze the relationships among green bonds, the digital economy index, and the energy transition in the Japanese economy. The analysis uses principal component analysis to evaluate the digital economy index, which includes fixed broadband subscriptions, mobile cellular subscriptions, internet accessibility, fixed telephone subscriptions, and the energy transition index, consisting of clean energy investments, energy efficiency, carbon emissions, and carbon intensity. This study uses the multivariate-QQR method to analyze the impact of parameters on energy transition in Japan and transforms the bivariate-QQR model into a multivariate framework. The study additionally utilized sensitivity analysis, kernel regularized least squares (KRLS) quantile regression, and Granger causality in quantiles (GCQ) to validate the benchmark assessments. The study's findings revealed that green bond issuance has significantly facilitated the transition toward renewable energy sources. We determine positive effects on the energy transition index in the digital economy index context, particularly within the middle to higher quantiles. These results emphasize a robust positive correlation between green bond issuance, digital economic growth, and Japan's transition to sustainable energy sources, primarily within middle and higher quantile segments. Additionally, the KRLS quantile regression and GCQ studies further supported the benchmark results. Furthermore, our findings suggest that Japan can strengthen its efforts to combat climate change and promote sustainable development by supporting green finance and digital development to achieve its sustainable development goals.