The subject matter of agricultural economics has both broadened and deepened and the chapters of this handbook present innovative work in the field. This volume contains part 5 of the handbook on "agricultural and food policy" and follows on from volume 2A which has chapters on "agriculture, natural resources and the environment" and "agriculture in the macroeconomy". Although agricultural economists have always paid attention to these topics, research devoted to them has increased substantially in scope as well as depth in recent years.