Shonkwiler, John Scott

December, 1996

By: Shonkwiler, John Scott; Shaw, W. Douglass
When a sample of recreators is drawn from the general population using a survey, many in the sample will not recreate at a recreation site of interest. This study focuses on nonparticipation in recreation demand modeling and the use of modified count-data models. We clarify the meaning of the single-hurdle Poisson (SHP) model and derive the double-hurdle Poisson (DHP) model. The latter is contrasted with the SHP and we show the DHP is consistent with Johnson and Kotz's zero-modified Poisson model.

July, 1995

By: Lambert, David K.; Shonkwiler, John Scott
This study attempts to link factors affecting the demand for Bureau of Land Management grazing to perceived changes in permittee welfare over the 1962-92 period. Annual demand for federal forage is found to be sensitive to active preference, beef cow and breeding ewe inventories, and grazing fees and nonfee allotment utilization costs. No evidence is found to support the notion that the demand for grazing has been affected by changes in property rights associated with the federal grazing permit that are not reflected in higher user costs. The total decrease in welfare generated from the permit that are not reflected in higher user costs. The total decrease in welfare generated from the permit to graze public lands has been about 9% per authorized cattle animal unit month and 65% per authorized sheep animal unit month over the study period.