“A gift is the transfer of a good without an explicit specification of a quid pro quo. The good can be a tangible thing or money, but it also can be intangible, as in the form of time, attention, information or knowledge. A present is a gift and so may be the attention that one person ‘gives’ another, or the time that a person donates to an art institute as a volunteer. Usually a gift entails reciprocity: the giver expects something in return for the gift given. Friends expect friendly gestures in return for their friendly gestures; donors expect some form of appreciation or another; and those who give presents at Christmas expect to receive presents in return. The key to understanding the phenomenon of the gift is the nature of the reciprocity involved”

Arjo Klamer, " 30 Gift economy http://www.klamer.nl/docs/1dec_2002.pdf." A handbook of cultural economics (2003): 243.