Surplus Extraction and Heightened Social Stratification
Economic extraction from peripheral and transborder areas is a well- recognized attribute of imperial systems (Hassig 1992; Luttwak 1976). Empires were highly extractive polities, and frontier regions provided them with the means to tap resources in the form of taxes, and beyond, as asymmetric exchange, diplomatic gifts, and forced tribute backed by punitive threat (Paynter 1985). In situations where transportation costs were high, military and frontier administrative infrastructure was erected to enhance agrarian and craft production. This provided the means to finance the frontier state activities. For example, indigenous populations in the Roman or Aztec frontiers were incorporated as tribute payers, and their work ranged from agriculturalists to specialized craft producers (Hassig 1992; D’Altroy 1992; Luttwak 1976). In the absence of state markets or standard monetary systems, the Inka exempted privileged ethnicities from paying tribute in exchange for their military service (Espinoza Soriano 2006 ; Wachtel 1982).