Wilson (1995) acknowledged that appraisers need to select highest and best use as a basis for estimating market value but took the view that the heuristic decision rules as a criteria for feasibility were superior to mathematical models rooted in economic theory that others believe is capable of improved analytical precision.

 

Weber (2005) finds that wide variations in appraised value of the same real estate by two or more appraisers at the same point in time results from using appraisal heuristics, which is often unsupported conjecture.  This method is based on suggestions in appraisal textbooks to use qualitative adjustment in difficult situations, instead of the quantitative methods, the basis of the scientific process recommended by Kinnard, Ratcliff, Graaskamp (and by the National Academy of Sciences (NAS) and Environmental Protection Agency (EPA) for the analysis of contaminated land). 

 

Weber et al (2005) and Weber et al (2006) describe the global use of scientific methods for the quantification of the existence, extent, and volume of subsurface contaminants.  These are the items that Kinnard et al. (2002) found to be the causal factors for the stigma that is found to reduce the market value of property that has contaminated soil.

 

Imagine the consequences if the EPA let brownfield owners select a dowser to tell them if there is subsurface contamination at their site. Also imagine that the business ethic, courts, etc. allow the property owner not to pay for the results of their subjective interpretation of the divining rod is not as desired. There would be absolutely no reliability in the results of the “environmental investigation.” Such is the case with appraisal, as will be discussed in a section that discusses how some state courts, the Appraisal Standards Board, and appraisal associations have been preventing the solution to the brownfield problem.