Richard T. Carson 
Stated Preference Approach to Environmental Valuation, Volumes I, II and III [PDF ebook] 
Volume I: Foundations, Initial Development, Statistical Approaches Volume II:Conceptual and Empirical Issues Volume III: Applications: Benefit-Cost Analysis and Natural Resource Damage Assessment

There is a truly enormous literature on using stated preference information to place a monetary value on environmental amenities. This three volume set provides the key papers for understanding the historical development of contingent valuation, its theoretical and statistical foundations, and the major controversies. It also contains representative papers covering all of the major application areas in environmental valuation.