ESG Correlates of Nuclear Power Persistence: A Joint Analysis of the Electricity Mix in Twenty-Nine Nuclear Economies

Nuclear power is usually treated as a determinant of emissions rather than as an outcome to be explained, and the few studies that explain it examine environmental, social and governance conditions one pillar at a time. Using an unbalanced panel of twenty-nine nuclear economies over 2004–2020, with 466 country-year observations, we analyse the nuclear share conditional on possessing capacity and estimate a single equation in which all three pillars enter jointly, comparing six estimators that separate variation between countries from variation within them. Fossil dependence is negatively associated with the nuclear share under every estimator, but the robustness is cross-sectional rather than temporal. Electoral democracy reverses sign across dimensions, positive between countries and negative within them, where it rests on a small number of closure episodes. Female parliamentary representation is negatively associated with the nuclear share across cross-sectional estimators, which provides ecological evidence consistent with the gender gap in nuclear risk perception; the mechanism itself is not observed. The methodological implication concerns validation: with 13.9 per cent of the variance being temporal, random cross-validation overstates the performance of flexible algorithms through panel leakage. The estimates are associations, rather than causal effects or evidence on adoption.