Hey, if you want to go photograph every sale in MLS for every assignment go for it, personally I think expenses can be better kept lower in other ways.
We agree. So I don't do it.
If you don't understand statistics and probability then I likely can not explain the logic to you. As for what can or can not be trusted, you can trust X so far, but VERIFICATION is another thing, and VERIFICATION is also required.
Best quote I can think of is from "The Golden Voyage of Sinbad" where a character said "Trust in Allah ... but tie up your camel!"
Let us suppose that GLA listed in MLS is either pulled directly from assessor records or some other source. Now let us suppose every GLA in MLS is off by up to 25% and either high or low (possibly random for each case). To estimate GLA prior to exterior inspection would likely require in depth analysis typing in room sizes and estimating hallways, bathroom, closet & other areas not in MLS. You could type in this data for every property in MLS or you could utilize probability to narrow things down a bit. Since the difference is up to 25% if you select properties within 30% of subject size you have a group of potential comps to consider. Now then, there are 3 methods to try to verify the size ... driving the comp and looking at the exterior (my mentor can usually estimate quite well from exterior), using statistical analysis (mentioned above), or calling the agent. If driving a comp takes < 5 minutes per, data analysis 10 min per, and calling an agent up to 15 min per then obviously the fastest method is exterior inspection (which often also yields other potentially comparable or divergent items) and you can check 3 properties that way compared to calling agents (who also could be wrong).
But hey, if you want to waste your time go for it!
This response makes my head spin. You're GLA example: Assume all GLA data, regardless of where it comes from is 25% off.
1. Then I guess the only way we appraisers will know the correct GLA of our comps is to go measure every house we want to employ in our reports. How else will the appraiser know the correct GLA to use?
2. (my mentor can usually estimate quite well from exterior)
WTF, now I know you are pulling my leg. This statement alone makes me question the validity of any comments you have provided. Really, your mentor had such acute visual powers as to determine the true GLA of a comp by just looking at the house from the street. And you want me to believe that your "mentor" was doing his due diligence? From your comment about your mentor, I have to believe that you admired him and probably now appraise as you were taught by him. Again, WTF!!!!!
3. Verify GLA with agent. You do realize that its the agents that provide the information found on the listing sheet so why would I call the same person who put in the incorrect GLA as my source of verification?
... and thus ALWAYS have to take TWO trips, one for subject & one for comps. So even if you have to inspect 3x as many properties in the field you often still gain time.
I can't hear you after your mentor comment!!!!!
I sense a reason break in there (aka, each sentence does not logically follow the one before it ... much like the "proof" that Alexander the Great has an infinite number of arms). You seem to be indicating an assumption that verification is used to massage non-comparable properties into "comps". No, you analyze the data, discover inconsistencies, and as ling as you are verifying sales anyhow try to discover why the apparent inconsistencies when making the verification calls. I mean, why verifiy terms of sale on a 300sf house on a city lot when your subject is a 3000sf house on 5 acres? Or why verify an REO/foreclosure that sold for less than half the price of non-reos if non-reos exist? (unless said has additional factors of importance, such as exact model match located next door when nothing else is either)
No credibility
Sometimes that can be so (especially if there is NO data on which to base a search, such as a new built with nothing in assessment card and prior sale was for vacant land) but you either learn how to punt or get clipped way too often.
So, why is doing verification calls too early in the process likely a bad idea?
Because then you are making way more calls than necessary, taking up more time than necessary, and doing so with less data on what you need to verify than if you waited until the proper time to make the calls.
If you do not know the appropriate time then either you need to figure it out (aka, "learn") or look forward to your first encounter with the state board.