07-29-2016 12:04 AM
I wonder why the confidence intervals (variance estimates) are slightly different when I run the exact same proc surveylogistic syntax using SAS 9.4 and SAS 9.3. For example:
proc surveylogistic data= abc varmethod= BRR;
repweights bsw1-bsw500 / df =24;
class sex (ref= '1') / param = ref;
The confidence intervals are slightly wider when I used SAS 9.4. Are there any differences between the two versions for this procedure?? I can't seem to find the information anywhere else.
07-29-2016 10:28 AM
The most likely reason would be the refinement of algorithms in the coding of procedures between releases.
Secondary posibilities are a change from a 32-bit to 64-bit implementation.
07-31-2016 07:23 PM
I would contact SAS Support with this, if you have concerns. It also depends on the differences, if their less than 0.0001 it's most likely precision issues more than anything else.