A gift or present is the transfer of money, goods, etc., without the direct compensation that is involved in trade, although possibly involving a social expectation of reciprocity, or a return in the form of prestige or power. In many human societies, the act of mutually exchanging gifts contributes to social cohesion. Economists have elaborated the economics of gift-giving into the notion of a gift economy.
Marcel Mauss and W.D. Halls, Gift: The Form and Reason for Exchange in Archaic Societies, W. W. Norton, 2000, trade paperback, ISBN 0-393-32043-XLewis Hyde: The Gift: Imagination and the Erotic Life of Property, 1983 (ISBN 0-394-71519-5), especially part I, "A Theory of Gifts", part of which was originally published as "The Gift Must Always Move" in Co-Evolution Quarterly No. 35, Fall 1982.