Longitudinal surveys for 1930,1940

I am trying to compare individuals that appear in both the 1930 and 1940 census data sets. I thought I could use histid, but there don’t appear to be any histid observations in either census. Is this correct? Is there any other way to identify the same individual in both censuses?

HISTID should be available for both the 1930 and 1940 full count census data sets. However, HISTID is available for researchers to track specific individuals as historical full count datasets are improved. In other words, it is not meant for linking full count census data sets.

We do have linked historical data sets here that might be of interest to you. At this time, data is linked in various sets from 1850 until 1930.