Michael Perelman asked:
>Wasn't Mishan the first to point out the difference between WTP and WTA?


An early reference to the concept of WTP vs. WTA is in:

Herfindahl, Orris, and Allen Kneese, 1965.  "Some Problems Associated with
the Use of Rural Areas."  Quality of the Environment.  Washington: Resources
for the Future, Inc., pp. 74-79.  

Michael Perelman suggests that maybe Mishan said it first. I don't know -
when and where did Mishan say it?

Either way, it's been around a long time, and should be raised whenever
evaluating the Coase (or Stigler?) theorems.

Mason Gaffney