The current paper contributes to the literature on the relationship between economic development and energy demand by assembling a wide panel dataset of energy consumption and prices for 37 OECD and 41 non-OECD countries. The unbalanced data spans 1960-2016, with the full 56 years of data for 17 countries and all countries having at least 18 years. In addition, our dynamic panel estimates address nonstationarity, heterogeneity, and cross-sectional dependence. Most results suggest that the GDP elasticity is less than unity (e.g., 0.7)-i.e., energy intensity will fall with economic growth. Most evidence suggests that the GDP elasticity is similar for OECD and non-OECD countries. and for non-OECD countries, similar across income-bands. Also, there is no evidence that individual country elasticity estimates (for GDP or prices) vary systematically according to income. The price elasticity is larger (in absolute terms) for OECD than for non-OECD countries-indeed, it is typically insignificant for non-OECD countries.