A gift or a present is the transfer of something without the expectation of payment. Although gift-giving might involve an expectation of reciprocity, a gift is meant to be free. In many human societies, the act of mutually exchanging money, goods, etc. may contribute to social cohesion. Economists have elaborated the economics of gift-giving into the notion of a gift economy. By extension the term gift can refer to anything that makes the other happier or less sad, especially as a favor, including forgiveness and kindness.