**Q: **

The PSID is not based on a simple random sample. What variables should I use for complex sample survey variance estimation?

**A:**

Variables ER31996 and ER31997 are used for computing sampling errors via balanced repeated replications. The same variables may be used with programs based on the Taylor Series linearization method (STATA SVY commands, SAS PROC SURVEY commands). BRR Stratum (ER31996) may be specified as the "Stratum variable" in the design specification. The BRR SECU variable (ER31997) may be specified as the "Cluster Variable". Note that despite the "BRR" prefix on theses variables they do constitute a correct specification of the stratum and cluster codes for an analysis with software that uses the Taylor Series linearization method.

This answer comes from the PSID FAQ area (#33).