Macroeconomic determinants of sustainable development in Vietnam: Evidence from wavelet quantile-on-quantile regression

This study examines the state- and horizon-dependent associations between public debt (DEBT), financial development (FD), inflation (INF), labour force (LF), trade openness (TRA), and sustainability (SDI) in Vietnam from 2000 to 2024. Wavelet quantile-on-quantile regression (WQQR) is applied to temporally disaggregated quarterly series to capture distributional heterogeneity across short-, medium-, and long-run horizons. Wavelet quantile correlation (WQC) provides complementary evidence, while estimates based on the original annual data assess sensitivity to temporal disaggregation. The results suggest substantial variation across quantiles and timescales. The positive DEBT–SDI and FD–SDI associations become more evident within selected medium- and long-run regions. No significant LF–SDI relationship is detected in the short run, although positive associations emerge over longer horizons. The INF–SDI nexus remains highly state-dependent, whereas the TRA–SDI relationship is fragmented rather than uniformly positive. These findings indicate the importance of debt quality, green financial intermediation, labour productivity, price stability, cleaner industrial upgrading, and environmental governance in Vietnam.