Jeffrey Prestemon USDA-Forest Service Southern Research Station   For. Sci. Lab., SRS, USDA FS PO Box 12254 Research Triangle Park, NC 27709 USA   jprestemon@fs.fed.us   http://www.srs.fs.usda.gov/econ/           JEL Areas: Q2 : Renewable Resources and Conservation: General Q5 : Environmental Economics: General