The field of ecological economics developed in the late 1980s at the intersection of the social and natural sciences, with roots in political economy, ecology and biology, and has had a significant impact on research agendas and policy in related fields in subsequent years. This collection of classic and contemporary papers in ecological economics and its precursors includes an introductory essay that explores how the field has developed over time and identifies the main strands in the literature. Volume I reviews the roots and evolution of ecological economics as a field. Volume II examines the methodological and technical challenges posed by the development of a new field at the intersection of a number of mature disciplines. Volume III focuses on the major developments in ecological economics of the last decade. Volume IV looks at the ecological economics of sustainability.