This article briefly reviews the core literature on the Golden Age of economic growth and tests the explanatory power of alternative theories against one another, with particular emphasis on the reconstruction thesis as developed by Jánossy. While previous empirical work on the subject relied on cross-sectional analysis, I employ panel-data techniques, which produce more robust estimates. I demonstrate that, for the core western industrialised nations, the rapidity and variety of economic growth during the 1950s and 1960s can mostly be explained by post-war reconstruction, the completion of which marked the end of the Golden Age. Labour-force expansion also made a very strong positive contribution. In the more peripheral countries of the OECD, however, rapid catching-up from the late 1950s was largely brought about by structural modernisation. Finally, human-capital accumulation has had a determining impact on long-run growth potentials, modelled here as time-constant country-fixed effects.