Oleksii Havrylenko

As the global community intensifies efforts to transition toward sustainable energy systems, the role of institutional and fiscal arrangements in fostering renewable energy has gained increasing attention. This study aims to assess whether fiscal decentralization contributes to the expansion of renewable electricity generation in OECD countries by analyzing panel data and identifying the direction and significance of this relationship. Utilizing a panel dataset of 34 countries spanning 2000–2023, the analysis employs a fixed-effects regression model with Driscoll-Kraay standard errors. It includes a one-year lag of fiscal variables to ensure robustness. The findings reveal a statistically significant but modest negative relationship between the share of subnational revenues in GDP and the share of renewables in electricity generation, suggesting that greater fiscal decentralization may not automatically incentivize renewable energy adoption. More specifically, the fixed-effects model corrected for heteroskedasticity and autocorrelation indicates that the coefficient for lagged subnational revenue (as a percentage of GDP) is negative and marginally significant (p ≈ 0.057), hinting at a potential delayed inhibitory effect. Additionally, country-level fixed effects demonstrate substantial heterogeneity, with nations like Iceland, Norway, and Canada showing systematically higher renewable electricity shares, regardless of fiscal structure. These results underscore the importance of complementary institutional frameworks and national coordination mechanisms to ensure that decentralization effectively supports climate policy goals.

Acknowledgment
This study was carried out within the framework of a research grant awarded by the Swiss National Science Foundation (grant no. IZURZ1_224119/1) and funded by the European Union grant “NextGenerationEU through the Recovery and Resilience Plan for Slovakia” (No. 09I03-03-V01-00130) and project VEGA – 1/0392/23 “Changes in the approach to the creation of companies’ distribution management concepts influenced by the effects of social and economic crises caused by the global pandemic and increased security risks”.

Type of the article: Research Article

Abstract
Global progress toward universal access to affordable, reliable, and clean energy has stalled, with over two billion people still lacking access to clean cooking, and affordability pressures are rising. AI is emerging as an energy-intensive technology and a potential enabler of more equitable energy systems. This paper assesses whether AI vibrancy contributes to advancing energy equity across countries while accounting for differences in economic capacity. The study employs a balanced panel of 36 countries from 2017 to 2023 (252 observations), drawing on the Global AI Vibrancy Tool, World Bank Open Data, and the World Energy Council’s Energy Trilemma Index. Box–Cox transformations were applied to address skewness, and panel econometric models (fixed and random effects) with robust standard errors were estimated. The FE model shows no significant within-country effect of AI vibrancy on energy equity (R² = 0.012). The RE model indicates a positive association: a one-unit increase in the AI vibrancy score results in an improvement of 0.00165 in the energy equity index (p < 0.01). At the same time, GDP per capita exerts a strong and highly significant effect (p < 0.001). The RE model explains 12.4% of the overall variation in energy equity. After correcting for heteroscedasticity and cross-sectional dependence, GDP per capita remains significant, whereas the effect of AI vibrancy weakens to marginal significance (p ≈ 0.09). Country-specific effects further reveal systematic over- and under-performance beyond what AI vibrancy and income predict, underscoring the critical role of governance and institutional quality in shaping energy equity outcomes.

Acknowledgment
The article was prepared as a part of the MSCA4Ukraine project 06030419, European Union’s Horizon 2020 Research and Innovation Programme. Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union, the European Research Executive Agency, or the MSCA4Ukraine Consortium. Neither the European Union nor the European Research Executive Agency, nor the MSCA4Ukraine Consortium as a whole, nor any individual member institutions of the MSCA4Ukraine Consortium can be held responsible for them.

Type of the article: Research Article

Abstract
The accelerating energy transition and uneven effectiveness of renewable energy policies across OECD member, accession, and key partner countries covered by the OECD policy database highlight the need to understand which policy designs deliver efficient outcomes. This study aims to assess how different regulatory policy instruments and their combinations influence the efficiency with which countries convert policy stringency inputs into renewable electricity generation outcomes. The analysis uses panel data for 47 countries over 2000–2023, combining Data Envelopment Analysis, Random Forest modeling, and fixed-effects regressions with lagged variables. The results show that the average DEA efficiency score is 0.348 (median = 0.258), indicating substantial underperformance relative to the best-practice frontier. Random Forest results reveal that structural factors dominate, with energy intensity (IncNodePurity = 2.53 × 10–12) and GDP per capita (1.44 × 10–12) exhibiting the highest variable importance scores. Among policy instruments, feed-in tariffs, renewable energy auctions, and emission standards have the most robust positive associations. Interaction effects indicate complementarity, with the joint impact of feed-in tariffs and auctions being positive and significant. In contrast, most individual instruments show limited or insignificant effects, confirming that policy effectiveness depends on coordinated policy mixes and structural conditions rather than isolated measures.

Acknowledgment
This article was prepared based on the results of the project 101127491- EnergyS4UA-ERASMUS-JMO2023-HEI-TCH-RSCH. Views and opinions expressed are, however, those of the authors only and do not necessarily reflect those of the European Union or European Education and Culture Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.