Regional growth and migration: a Japan-United States comparison

"Do poor economies grow faster than rich ones? This...economic question...is analyzed in this paper using two regional data sets: 47 prefectures in Japan and 48 states of the United States. We find clear evidence of convergence in both countries: poor prefectures and states grow faster. We also find that there is intraregional as well as interregional convergence. We analyze the cross-sectional standard deviation across prefectures and states.... Finally we study the determinants of the rates of regional in-migration.... We find little evidence in favor of the argument that population movements are the reason why we find convergence across economies."