Twin peaks : growth and convergence in models of distribution dynamics

Convergence concerns poor economies catching up with rich ones. At is- sue is what happens to the cross sectional distribution of economies, not whether a single economy tends towards its own steady state. It is the latter, however, that has preoccupied the traditional approach to con- vergence analysis. This paper describes an alternative body of research that overcomes this shortcoming in the traditional approach. The new findings on persistence and stratification; on the formation of conver- gence clubs; and on the distribution polarizing into twin peaks of rich and poor|suggest the relevance of a class of theoretical ideas, dierent from those surrounding the production-function accounting traditionally favored.