Baskaraagac, Nermin Yasar2026-04-032026-04-0320261452-595X2217-2386https://hdl.handle.net/20.500.12416/15997https://doi.org/10.2298/PAN221012008BThis study evaluates energy intensity convergence in Commonwealth of Independent States (CIS) economies in comparison to the OECD average from 2000 to 2019, utilising beta-convergence and sigma-convergence analyses based on conventional unit root analysis alongside the KSS stationarity approach, which accounts for data nonlinearities, and the Phillips-Sul club convergence procedure. The results indicate that most CIS countries did not achieve energy intensity convergence during the period under review. Furthermore, while the Phillips-Sul test classifies all studied countries, including the OECD-20, into a single convergence club, it only presents weak evidence of significant convergence. This limited convergence is likely hindered by the continued presence of Soviet-era manufacturing infrastructure in many CIS economies. From a policy perspective, the development of comprehensive economic frameworks that incorporate legal, institutional, technical, and financial reforms, supported by targeted investments in research, cutting-edge technologies, and updated standards, is essential to significantly boost energy efficiency and effectively address challenges on both the supply and demand sides.eninfo:eu-repo/semantics/openAccessEnergy IntensityConvergenceEconomic GrowthUnit RootNonlinear StationarityArticle10.2298/PAN221012008B