Sampling variability associated with case?

In 2000, one in six households filled out the LONG form of the census.

Does IPuMS-USA have information about WHICH one-in-six of households filled out the LONG form? That variability must be controlled for under aggregation.

The unweighted standard deviation is a biased measure of error margin and will be an inconsistent estimate of confidence if the variability that went into the process of choosing the households is not accounted for.

Are there any measures of sampling error in IPuMS-USA samples?

The weights might SCALE the error, but do not determine its densities.

All cases in the PUMS files, which are used to create the IPUMS data, come from respondents who were asked to fill out the long form. We don’t have any additional information regarding the selection of the long form respondents, but you can find the Census Bureau’s documentation here.