In many countries of the world, both developed and developing, agricultural extension services are shifting from the public to the private sector. Services are thus being contracted out, in order to improve the financing and delivery of agricultural knowledge. This volume presents work developed by the Agricultural Knowledge and Information Systems (AKIS) Thematic Group of the World Bank, in collaboration with the University of Maryland, to examine contracting for extension services. "Extension" is used broadly to include all agricultural information transfer programmes and activities, including advisory services to farmers. A range of case studies from countries as diverse as Australia, Bangladesh, Chile, China, Germany, Mozambique, Portugal, Uganda and USA, is presented to demonstrate the range of approaches.