The TCM and CVM and HPM approaches
The CVM and HPM methods have an infinity with the TCM in certain circumstances. For example, where it is planned to improve the environmental quality of a site for which there is an entry fee that is likely to adversely affect the visit rate of a similar un-priced one. In such a case it is of interest to the management of the latter, by mean of a CVM approach, what the WTP for both site will be after the improvement has been completed. While the linkage of CVM and TCM has not been pursued, that of HPM/TCM certainly has. There are situations in which the characteristics of two sites are a factor in determining the number of visits. Where two sites are under consideration that are identical except for one important environmental attribute, the difference in visit rate and therefore the estimate of the total value of each can be explained by the value of this one attribute. Brown and Mendelsohn (1984) developed the approach in a study of the demand for fresh water fishing where characteristics such as landscape, level of visits and the quality of the fishing water were perceive as significant. The drawback of the combination of HPM and TCM is that it suffers from the problems associated with both.