Frontier-based productivity analysis emerged as the dominant paradigm for measuring growth, merging efficiency concepts with frontier estimation to quantify performance gaps. Researchers emphasized decomposing productivity into contributions from factor accumulation and efficiency improvements and they developed tools that separate random error from true inefficiency in empirical settings. The methodological focus linked microlevel efficiency assessment with macro growth accounting and highlighted the role of investment dynamics in shaping productivity trajectories. Historical Significance: The period solidified frontier approaches as a standard framework for productivity research, introducing models that distinguish noise from inefficiency and enabling comparable measures across industries and economies. It laid the groundwork for subsequent growth accounting, efficiency measurement, and investment dynamics research, shaping both theory and policy analysis for decades.