- Joined
- Jun 27, 2017
- Professional Status
- Certified General Appraiser
- State
- California
You mean 100+ sales. They're not comps.
Who says? The regression model is based on the input data, which are sales transactions that may go back many years, and may cover a large market area. But given the power and flexibility of MARS, useful information can be extracted from them so they are all being compared to each other to create a model - and they all have equal weight (unless I choose otherwise). The transaction dates which may extend into the past 20 years, will have the time factor extracted as a regression variable, so, essential as we draw near the current effective date, the latest sales will have the most weight. But some properties have rare features tha appear in sales maybe once every several years. The ability of MARS to extract values from the rare features is one of its strengths.
Now, you might define "Sales Comparable" as only a sale you choose to put in the Sales Grid. But I may use a very old sale to support a value adjustment on some rare feature in addition to required Sales Comparables. As far as I am concerned, all 100+ sales comparables are candidates for the Sales Grid, if there is some good reason to put them in. I regard all sales transactions that go into the creation of a value model as "sales comparables." What goes into the Sales Grid are "Display Comparables."
Appraisers choosing say 6 more similar comps and reconciliating which are given more value are better in accurate valuation than current computer models.
Your understanding of valuation only goes so far. That's fine. You are working in the realm of "traditional appraisal." You are only working within your limiting definitions and understanding. I presume some appraisers, not many, can see beyond such limitations.