Military spending and sustainable economic development have been widely discussed in recent decades. Especially in Romania, the defense budget is valued at $4.8 billion, registering a compound annual growth rate (CAGR) of 23.57%. It is also expected to reach $7.6 billion in 2023, according to a report by Strategic Defense Intelligence. There is no consensus in current research and less attention is paid to Eastern European countries. Considering the significant increase in military spending in Romania in recent years, as well as the occurrence of political events, this paper focuses on the dynamic causal relationship between military spending and sustainable economic growth in Romania. The bootstrap rolling window causality test takes into account the structural changes, and therefore, provides more convincing results. The results indicate negative effects of military expenditure on sustainable economic growth between 1996–1999 and 2002–2004. It can be attributed to the crowding-out effect of public expenditure on private investment. The positive effect between the two variables analyzed is noticed with the accession of Romania to the North Atlantic Treaty Organization. Conversely, it is found that economic growth does not have a significant effect on military spending in Romania. Policymakers should guard against the crowding out of private consumption and investment due to excessive military spending and ensure to increase military expenditure on the premise of sustainable economic development.

This study sought to ascertain the existence of convergence in environmental taxation among EU countries. By employing the sequential panel selection method and the panel KSS unit root test, it is demonstrated that the environmental taxation sequences in Luxembourg, Germany, Spain, France, and Cyprus diverge, while those of the remaining 22 countries converge. Similarly, the energy tax sequences of Croatia, Spain, Germany, and France are unstable, indicating divergence, while the remaining 23 countries exhibit significant convergence. Finally, transport taxes show a convergent trend across all EU countries. The convergence of environmental taxation can be explained by the catch-up and spatial spillover effects, and the non-convergence of a few EU countries is attributed to their minimal implementation of environmental goals. This study provides recommendations for improving environmental policies.

The significance of democratic commitment is highlighted on a global scale by the importance placed on offering a multitude of chances to establish enduring ecosystems and foster economic progress. Social finance, capital formation, and green finance have recently received a lot of attention from this perspective. Past studies mainly examined social finance and green finance in isolation. When investigating the individual impact of these important variables on economic growth in the occurrence of important events like the COVID-19 pandemic and other environmental pollution issues, most studies have mainly focused on developed countries, ultimately ignoring the different dynamics in emerging economies. The purpose of the research is to investigate the joint interaction between social finance (Social Impact Bonds), capital formation, and green finance (green loans, green investments, and green security) on economic development in BRICS economies. This research employed a longitudinal dataset from 2013 to 2023. The generalized method of moments (GMM) and fixed effect model (FEM) were employed in this research as statistical techniques for estimating parameters. The findings of this study revealed a positive joint relationship between green finance, capital formation, and social financing on economic development of BRICS economies. Therefore, measures that jointly promote social and green finance amidst environmental challenges or economic risks could present opportunities to mitigate the vulnerability of a country's economic prosperity. This research will surely guide policymakers in developing economies on how to give considerable attention to sustainable aspects while formulating policies and strategies aimed at economic development.

Enhancing green total factor energy efficiency (GTFEE) is crucial for achieving sustainable development. Against this backdrop, this study aims to investigate the impact of fintech on GTFEE, using annual data from 240 Chinese cities between 2011 and 2021. Methodologically, we employ the SBM–Malmquist–Luenberger model to measure GTFEE and assess the role of fintech. The results demonstrate that fintech significantly promotes GTFEE, a finding that remains robust after addressing endogeneity issues and replacing key variables. Further mechanism analysis reveals that fintech facilitates GTFEE by alleviating financing constraints and stimulating technological innovation. Moreover, the effect is particularly pronounced in eastern regions, non-resource-based cities, service-oriented cities, and larger urban areas. Importantly, quantile regression results confirm that fintech exerts a stronger positive impact at higher quantiles of the GTFEE distribution. These findings offer both theoretical insights and practical policy implications for advancing energy efficiency through fintech development.