An exploration of relationships between urbanization and per capita income: United States and countries of the world

"The relationship between urbanization and level of income has been the subject of considerable theoretical debate and empirical study for many years. However, little recent work has been done to determine whether or not previous findings still hold, and there has been even less multi-country analysis to explore the degree of generality. Analysis of data for metropolitan areas in the United States from 1970 to 1990 indicates per capita income increases directly with population size. For states of the United states and 113 countries for 1960 and 1980 a strong positive relationship exists and holds temporally between level of per capita Gross Domestic Product and percent of the population that is urban."