benefit cost analysis or evaluation of Federal actions. When 

 performing natural resource damage assessments, U.S. Department 

 of the Interior regulations require that the calculation of 

 economic values lost to society be measured in terms of net 

 willingness to pay (U.S. Department of the Interior, 1986). Use 

 of net willingness to pay is also recommended in textbooks on 

 benefit cost analysis (Sassone and Schaffer, 1978; Just, Hueth, 

 and Schmitz 1982) . 



