"The share of metropolitan residents living in central cities declined dramatically from 1950 to 2000. We show that, if not for a series of demographic factors - notably renewed immigration, delayed child bearing, and a decline in the share of households headed by veterans, who are eligible for...

Why do larger countries have more armed conflict? This paper surveys three sets of hypotheses forwarded in the conflict literature regarding the relationship between the size and location of population groups: Hypotheses based on pure population mass, on distances, on population concentrations,...