matched paired analysis

[Terrel L. Shields]

On a somewhat related note, use of binary variables (1 = Yes, 0 = No) should be used very sparingly, overloading a model with several different binaries can tend to cause autocorrelation and heteroskedacity. A good rule of thumb if you use binaries (or any variable for that matter) run the model with a variable. Run the model again without the varaiable...do the numbers change R2 better or worse. Sometimes the siginificance of a variable is just modeling off another variable...removal of a significant variable, that results in no or little change to R2 should tell you whether or not there is a lot of auto correlation in a model with that variable or another...ie bedroom count to GLA.

Totally agree, again I try to keep the issues to a minimum. I have RealStat and you can input numerable variables but frequently this muddies the waters. But use of those dummy sets to check for Fireplace, etc. and that is why I say what I did about fireplaces....they simply don't show up consistently as an obvious value increaser and are much more likely to reflect a quality or age issue. Quality in that certian styles of homes seem to have fireplaces and in the cold clime of the late 1970s a much higher percentage of homes had a functional fireplace - often with doors, blowers, etc. Many older homes had shallow fireplaces that were decorative and most houses with fireplaces in the last 15 years in our area are either gas log or decorative.

 

[Lee Lansford]

...suggesting poor comparison. But data is not always perfect...so you live with what you can.

Amen, amen!

There are instances where the market presents the appraiser with a sold property that is not a good, direct market substitute for the subject, but it is useful because it is an indicator of what the subject is not...and, sometimes that is a starting point.

 

[fifteen]

I'm so pixssxxed you guys aren't getting minimum wage

 

[Don Clark]

Amen, amen!

There are instances where the market presents the appraiser with a sold property that is not a good, direct market substitute for the subject, but it is useful because it is an indicator of what the subject is not...and, sometimes that is a starting point.

Lee,

There is one local appraiser, a USPAP instructor who has the formula. When he completes a report, and after making adjustments, what ever is left over, he adds enough of an adjustment so that all sales come out to the same adjusted value. He calls that matched pairs analysis

 

[Kali the Boston Terrier]

I'm so pixssxxed you guys aren't getting minimum wage

So far from minimum wage, I'm not even sure what it is anymore.

 

[timd354]

Lee,

There is one local appraiser, a USPAP instructor who has the formula. When he completes a report, and after making adjustments, what ever is left over, he adds enough of an adjustment so that all sales come out to the same adjusted value. He calls that matched pairs analysis

Its pretty frightening that somebody who does that is actually teaching USPAP. I wonder how he explains the adjustment and where he places it in the grid. Maybe he calls it the Comparable Equalization Adjustment....lol
m2:m2:m2:

 

[CBBoston]

Brian and Terrel once again are trying to promote the use of regression to residential appraisers. At least Terrel, for the most part, only uses it as a cross check for matched pairs. If you dig around a bit, you will find a couple looong treads devoted to regression. What you should pick up is that simply throwing a few sales into a regression model and using the independen variable coefficients for adjustments is a no-no. There are lots of technical reasons for that. If you really are set on trying to use regression for explanatory purposes, you should take a college course on multiple regression. The appraisal course in regression way over simplify the process and caveats. Keep in mind that AVMs are pretty much nothing but regression models which only try to predict value and not explain it. (statistically there is a big difference in the two.) Now just think about how good AVMs are. That should give you pause about using regression for explanatory purposes.

 

[Kali the Boston Terrier]

Oh I'm not an advocate for use of MLR in residential as a means for obtaining adjustments...but rather in determining qualitative differences. As I have said in those other really long threads I believe MLR to be a very dangerous tool for the residential appraiser. But i do believe it has its benefits, which should not be discounted automatically...

However I do believe linear trending should be used more, not neccessarily MLR but single variable...

 

[fifteen]

hahahahaaa indisputable hahhaaa

Lee,

There is one local appraiser, a USPAP instructor who has the formula. When he completes a report, and after making adjustments, what ever is left over, he adds enough of an adjustment so that all sales come out to the same adjusted value. He calls that matched pairs analysis

 

[fifteen]

I have a serious question to ask the math wizzes around here. Do either of you 3 think using listings as a marker for depreciation is viable? Banks are requesting this theorum more and more, I think it's faulty. http://ercappraisaltraining.org/resources/

There are 3 kinds of people in this world, those that can add and those that can't.