In recent literature on monetary policy, it has been argued that a sensible policy rule should be able to induce learnability of the fundamental equilibrium: if private agents update their beliefs over time using adaptive learning technques, they should be able to converge towards rationality....

This paper studies the international business cycle behaviour across 25 advanced and emerging market economies for which 125 years of annual GDP data are available. The picture that emerges is more fragmented than the one drawn by studies that focused on a narrower set of advanced market...