"Sample" Appraisal: Subjective Value Containment Approach

[RCA]

I continue to struggle with the ability to believe that there is a statistically relevant sample size to validate multivariate regression without using older data, which may not be reflective of current market forces. Or, have to include recent market data that does not correspond closely enough to the subject characteristics and hence introduces correlative dissonance. Then, after all of this modeling time, to try to build another model because the next subject has different attributes, especially for non-residential properties.

Hey, you just put SaleAge in the data as <effective date of appraisal> - <date of sale>. Now, interestingly, everything that is dependent on date of sale will to into that adjustment, e.g. changing interest rates, house market sales activity and so on. You can go way back in time. And the further back you go - the more different combinations of property features you will see. And MARS loves all that variety - that is what makes it happy.

However, there are some things that will not synch with date of sale. "Global" things sych. But user tastes which say move popularity of one house style ahead of another are different. You can get around that by making sure that you input house style, switch on two-way interaction for house style and date of sale/sale age - and you will get a time based adjustment for each house style (or whatever). This is where the analysts experience comes into play.

 

[RCA]

i mean this with the best intentions.

bert, you are too smart for us lowly residential appraisers.

seriously, you are putting way to much into this. stick to your software engineer work where your brain can be utilized for good.

This can be made easier. But it is still new. If appraisers don't do it, someone will. This technology just keeps moving forward. When Google engineers run out of things to do, anything is next.

 

[ltyrni]

To be honest, some redaction is necessary to make it look real. But


OK. What is wrong with that? Mars is that exact. Far more exact than a human. I can make these adjustments no problem. If you are using traditional methods, the argument can be made you are not capable of that kind of accuracy. I'm guessing that is kind of what you are talking about.

In other words, if MARS puts an adjustment out that amounts to $1,400 --- it has determined that it is significant. So, yes, I would use it.

Bold is my emphasis.

I am just a casual lurker reader from time to time, but this needs needs highlighted. You can't portray yourself as that precise since it could be construed as a guarantee; that you are no longer stating an "opinion of value" but rather a "fact".

I'm not terribly worried about anything I've seen here replacing appraisers on merits. It just isn't impressive at all. I can see it replacing appraisals though if the banks and regulators just want some low quality, number charade that will allow them to make loans with the veneer of "due diligence". Then low confidence, automatic value evals from a computer program can be fine.

 

[George Hatch]

The irony is that the better your dataset is the less effort it takes to get to a reasonable result. If the data is great than ANY valuation model will work, including the monkey with the dartboard.

Our users don't need us for appraisal problems that are so easy that even a calculator can do it. They need us for the appraisal problems that are so tough the calculator can't do it. Which (so far) is probably most of them.

 

[RCA]

The irony is that the better your dataset is the less effort it takes to get to a reasonable result. If the data is great than ANY valuation model will work, including the monkey with the dartboard.

Our users don't need us for appraisal problems that are so easy that even a calculator can do it. They need us for the appraisal problems that are so tough the calculator can't do it. Which (so far) is probably most of them.

Well as long as the data is simple. I think my database has 6 million records of 4000 fields. I'm not sure where you would start with your monkey.

You can get started here: https://ddwiki.reso.org/display/DDW17

Go down to the Lookup fields. So many.

 

[Red Flint]

Hey, you just put SaleAge in the data as <effective date of appraisal> - <date of sale>.

However, there are some things that will not synch with date of sale. This is where the analysts experience comes into play.

Okay, follow. Thanks for the example of the multivariate adaptive regression splines applied to an appraisal problem, cool. Pacifica is a little too foggy with a nasty riptide, and ooh, those house prices. Enjoy your day.

 

[James Micozzi]

Well of course, there is the possibility I did some global changes, search and replace in Acrobat. That never entered your mind I suppose.

Sorry. Don’t buy your bulls**t.

 

[George Hatch]

Take it easy, friends. This topic is worth discussing on it's own merits.

 

[gregb]

Bert's Cost Approach should have been omitted, and his Income Approach was weakly developed, using a cap rate for a SFR based on multi family. Oy, if his report had been submitted as an AI demo report, I would not choose to read that outcome. The SCA I am still marinating over.

 

[Addie]

Ouch....this thread is cringeworthy.



@Bert Craytor You just got served