A "purchasing cooperative" is a type of cooperative arrangement, often among businesses, to agree to aggregate demand to get lower prices from selected suppliers. Retailers' cooperatives are a form of purchasing cooperative. It is often used by government agencies to reduce costs of procurement. Purchasing Cooperatives are used frequently by governmental entities, since they are required to follow laws requiring competitive bidding above certain thresholds. Counties, municipalities, schools, colleges and universities in the majority of states can sign an interlocal agreement or contract that allows them to legally use a contract that was procured by another governmental entity.