Reciprocity denotes a relationship of exchange and mutual benefit, commonly referring to transactions external to the formal, money-mediated market (see Cochrane). Reciprocity is based in social interaction, where peers negotiate their informal debts and credits to one another (see Prieto; and Radović). Reciprocity is used as a technical term in many different fields, from psychology to international relations, but common among them is the belief that relationships depend on an acknowledgment of mutual responsibility (see Murphy; Naveau; Muehlebach; and Shear).