In their article "An Arbitrage-Free Approach to Quasi-Option Value" [J. Environm. Econom. Management 35, 103-125, 1998], Coggins and Ramezani interpreted the concept of quasi-option value introduced by Arrow and Fisher [Quart. J. Econom. 88, 1974, 312-319] as being identical to Dixit and...

Fisher [2000, this journal] offers a unifying framework for two concepts of (quasi-) option value suggested by Arrow, Fisher, Hanemann, and Henry (AFHH) on the one hand, and by Dixit and Pindyck (DP) on the other, and claims these two concepts to be equivalent. We show that this claim is not...