Hi
I have some very strong linear independent variables that are not
collinear, all tolerances>.8. Also note that all the coeficients are
positive, as expected in the real world and have small coef of
variation (and standard error). It seems to me that the pint estimates
of the odds ratio tend to be large when you have powerful independent
variables which can nicely segment the binary response.
Should I be overly concerned about the point estimates and would
better bucketing and dummification help.
I had a 50% hold out sample(75,000 observations) and the model results
where indistinguishable from the development model. Also I have had
good results applying the model to similar popualtions.
At least we have lower bounds on the point estimates.
Standard Wald
Parameter DF Estimate Error Chi-Square Pr > ChiSq
Intercept 1 -7.1677 0.1343 2847.2526 <.0001
AGE 1 7.8295 0.6147 162.2461 <.0001
GENDER 1 7.8149 0.9116 73.4927 <.0001
INC_TOTAL 1 5.9408 0.4784 154.2415 <.0001
SCHOOL 1 6.2133 0.5420 131.4006 <.0001
EQUITY 1 7.3206 0.5799 159.3500 <.0001
IVY_LEAGUE 1 3.9864 0.2986 178.2598 <.0001
STOCKS 1 7.2808 0.2462 874.5103 <.0001
Odds Ratio Estimates
Point 95% Wald
Effect Estimate Confidence Limits
AGE
GENDER >999.999 753.493 >999.999
INC_TOTAL >999.999 414.983 >999.999
SCHOOL 380.251 148.901 971.053
EQUITY 499.333 172.590 >999.999
IVY_LEAGUE >999.999 484.899 >999.999
STOCKS 53.858 29.999 96.693
>999.999 896.237 >999.999
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xlr82sas
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2/8/2011 10:13:51 PM |
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> =A0 I have some very strong linear independent variables that are not
> collinear, all tolerances>.8. Also note that all the coeficients are
> positive, as expected in the real world and have small coef of
> variation (and standard error). It seems to me that the pint estimates
> of the odds ratio tend to be large when you have powerful independent
> variables which can nicely segment the binary response.
Is this a case of complete or quasi-complete separation? In simple
terms, the model is predicting 'too well'
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BruceBrad
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2/11/2011 2:15:45 AM
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