The variable UGGPA (undergraduate GPA) is available from IPUMS only for the 1990s NSRCG but no for the 2000s NSRCG. However, it seems that this variable is still in the 2000s NSRCG survey and is still part of the public data. Is there any specific reason why it is no longer included in the IPUMS 2000s NSRCG data? Should I pay attention to that reason, if I want to analyze this variable? Many thanks!
IPUMS Higher Ed only includes data that was available in the SESTAT (Integrated Survey Data) files (a subset of the files available from the NSF here). In some years, the integrated files contained fewer variables than the standalone files associated with the same survey that year. That’s the case with the post-1999 NSRCG and UGGPA. You should be able to merge in data from those later years to your IPUMS extract, using REFID as a linking key (note this must be done within a sample, because some individuals appear in multiple samples and therefore would have repeated REFID values in a combined dataset). I believe the codes for UGGPA in the post-1999 NSRCG files are consistent with those used by IPUMS Higher Ed, but I suggest you double check this with the documentation of those files.
Thank you very much! This is super helpful.