The Context for substitutes in CVM studies
The purpose of this paper is to report results from a set of experiments that provide data to test the NOAA  Panel recommendation that subjects be reminded of budgetary substitutes when providing values. The results suggest that simply reminding subjects of alternative environmental goods does not affect the distribution of values for a specific good. Such values are affected, however, whenever subjects simultaneously value alternative goods.
Social and Behavioral Sciences
Neill, H. R.
The Context for substitutes in CVM studies.
Journal of Environmental Economics and Management, 29(3),