The period reframed macroeconomics around aggregate demand, introducing active fiscal and monetary policy to stabilize output and employment and emphasizing that unemployment stems from insufficient spending. The approach unified theory with empirical regularities, guiding policy-oriented research and shaping subsequent macroeconomic methodologies. Historical Significance: The era established a durable stabilization framework, integrated open-economy considerations across exchange-rate regimes and capital mobility, and anchored growth-oriented development narratives in macro policy discourse, influencing future modeling and international policy debates.