Energy and Greenhouse Gas Emissions Intensities in Four Developed Economies

This study examines annual changes in primary energy use and energy-related greenhouse gas emissions, measured per unit of real GDP and per capita, in the United States (USA), Australia, Germany, and Japan. Annual levels cover 2000–2019; the principal regressions use a matched 2005–2019 sample of 60 observations. Country-fixed-effects regressions are compared with pooled least squares, country and year effects, alternative lags, sequential country exclusions, and measures that reduce contemporaneous overlap between regressors and outcomes. Coal growth is positively associated with all four outcomes in contemporaneous specifications, but these associations do not persist when coal is lagged. The negative electricity-to-energy ratio coefficients also depend on variable construction and are not evidence of a separately identified electrification benefit. Renewable-energy growth is consistently negatively associated with emissions growth per unit of GDP across the reported specifications, although precision varies. Several price, services, finance, income, and knowledge coefficients depend on the chosen lag structure. The study therefore contributes a transparent comparison of conditional annual associations and their sensitivity, rather than causal policy effects or long-run elasticities. Its findings support distinguishing energy intensity from per capita use and domestic emissions performance from the carbon content of trade.