Convergence Across States and Regions
研究了1880年以来美国各州和地区的人均收入增长与趋同，发现贫困州增长更快，但趋同速度约为每年2%；同样框架应用于欧洲七国73个地区，结果类似。
In this paper we examine the growth and dispersion of personal income in U.S. states and regions since 1880 and relate the patterns for individual states to the behavior of regions.Then we analyze the interplay between net migration and economic growth.We study the evolution of gross state product since 1963 and relate the behavior of aggregate product to productivity in eight major sectors.The overall evidence weighs heavily in favor of convergence: poor states tend to grow faster in terms of per capita income and product and within sectors as well as for state aggregates.The rate of convergence is, however, not rapid: the gap between the typical poor and rich state diminishes at roughly 2% per year.We apply the same framework to patterns of convergence across 73 regions of seven European countries since 1950.The process of convergence within European countries is similar to that for the United States.In particular, the rate of convergence is again about 2% per year.