The Moka is a highly ritualized system of exchange in the Mount Hagen area, Papua New Guinea, that has become emblematic of the anthropological concepts of "gift economy" and of "Big man" political system. Moka are reciprocal gifts of pigs through which social status is achieved. Moka refers specifically to the increment in the size of the gift; giving more brings greater prestige to the giver. However, reciprocal gift giving was confused by early anthropologists with profit-seeking, as the lending and borrowing of money at interest.
This gift exchange system was analyzed by anthropologist Marshall Sahlins as a means of distinguishing between the exchange principles of reciprocity and redistribution on the one hand, and the associated political principles of status and rank on the other. Sahlins used this example to contrast the regional political differences between the status-based "Big man" political system of Melanesia that engage in gift exchange, with the socially ranked "Chiefly" political systems of Polynesia associated with redistributive systems.