War shocks, migration, and historical spatial development in China

North China was traditionally the cradle of civilization in China, and yet most of its largest cities today are located in the south. Using a unique gridded (1∗1°) data set of population density for nearly two millennia, we show that the center of economic gravity had gradually shifted to the south between the 3^rd and 12^th centuries as a result of mass migration, of which nomadic intrusions were the key driving force. Evidence shows that the destination regions saw significant growth in population density and urban agglomeration after each wave of migration. Moreover, as it was the elites who spearheaded the migratory move, they not only brought with them their own (upper-tail) human capital, but also perpetuated a persistence of human capital investment over time as manifested in a significantly higher density of jinshi scholars in the imperial civil service exam and number of Confucian academies in the past, and years of schooling today.