Clientelism is the exchange of goods and services for political support, often involving an implicit or explicit quid-pro-quo. It is a political system at the heart of which is an asymmetric relationship between groups of political actors described as patrons and clients and political parties. Richard Graham has defined clientelism as a set of actions based on the principle take there, give here, with the practice allowing both clients and patrons to gain advantage from the other's support. Moreover, clientelism is typified by "exchange systems where voters trade political support for various outputs of the public decision-making process."