Regime-dependent dynamics of nuclear and coal energy in high-income economies: evidence from a Markov switching analysis

Introduction Nuclear energy remains a key low-carbon source in high-income economies, whereas coal continues to account for a substantial share of greenhouse-gas emissions. Methods This study examines the regime-dependent behaviour of per capita nuclear and coal energy production from 1965 to 2023 using a Hidden Markov Model (HMM). Structural breaks, volatility shifts, and persistent production regimes are estimated via the Expectation–Maximisation algorithm and smoothed state probabilities. Results The results indicate strong persistence in the medium- and high-production regimes of nuclear energy, while coal exhibits a gradual yet sustained transition from high toward low regimes, consistent with long-term decarbonisation efforts. Conclusion Overall, regime-switching dynamics highlight differing adjustment paths: nuclear production shows cyclical shifts linked to policy/technology cycles, whereas coal reflects a long-run structural decline across high-income economies.