The past decade has seen an explosion of empirical research on eco-nomic growth and its determinants, yet many of the central issues of inter-est remain unresolved. For instance, no consensus has emerged about the relative contributions of capital accumulation and improvements in total factor productivity in accounting for differences in growth across coun-tries and time. Nor is there agreement about the role of increased educa-tion or the importance of economic policy. Indeed, results from the many studies on a given issue frequently reach opposite conclusions. And two of the main empirical approaches—growth accounting and growth regres-sions—have themselves come under attack, with some researchers going so far as to label them as irreleva...