bradellis & Neil: With all due respects, you guys could not be further from the truth. Bradellis said; “No mathematical model will be able to measure the intangible aspects of how both buyers and sellers make their decisions.” Reply: Regression comes closer to doing that than any known methodology, except of course Mrs. Cleo. The only way to deal with intangibles is on a statistical basis. If you think the regression model cannot account for intangibles, then how do you think the present method of using adjustments out of sequence and totally unsupported by data can do it? In a side-by-side comparison regression makes a mockery of the existing model, which is its self, a crude regression model. Each existing method of estimating price is in and of itself a regression model and the entire appraisal process is collectively a crude intuitive regression model. The only difference is that math regression modeling is based on statistical data and the existing method relies on the intuition of the appraiser.

Neil says that regression does not address randomness. To the contrary, nothing addresses it better. If you pick the 30 most comparable sales, the regression predicts a sale prices with a small variance from the actual sale prices, and then what is left is general randomness. Mathematically, the law of numbers says that the present appraisal method cannot even answer the question the definition of market value ask, that being “what is the most probable price.” The present method doesn’t even address general randomness nor does it acknowledge the covariance of independent variables. General market randomness and covariance of variables far exceeds in significance any major adjustment on the existing marketing grid and the existing marketing grid does not address these factors. The test of any model is how well does it explain the correlation of price (dependent variable) and value influencing factors (independent variables). Regression modeling verifies its prediction and does it with a statistically significant amount of data. The present method asks up to just take the appraisers word for it. The present cost approach is based on one theory and the sales comparison is based on a totally different algorithm. As an analogy, the cost approach puts a watch together in one sequence based on one theory, and the sales comparison approach attempts to take it apart in another sequence based on another theory. The income approach recognizes collective obsolescence as reflected by the market generated rental level, and the cost approach attempts to measure it piece meal. How many times have you heard it said: "The cost approach is always higher and sets the upper limit of price." Well that is the reason, you can't measure covariance of variables using a piece meal methodology.

Then too, how can you criticize and condemn something that you haven’t even seen?