Number of Family's below Income Threshhold

Hello,

I am looking to find the number of families below a certain income threshold in my state.
If FTOTINC represents individual family income, then how come there is a weighted household variable (HHWT) in the same column representing multiple households (ex. 17)? Is FTOTINC a median or aggregate income of multiple families (seems oddly specific to be)?

My approach is to find number of family households using HHTYPE (1-3), then use HHWT to count the number of families in each sample that are below a certain income (using the FTOTINC value associated with each HHWT).

Thank you for any information you might have!

Households in the ACS consist of all residents of a housing unit, and households sometimes contain more than one family, as defined by FAMUNIT. Family income as measured by FTOTINC is an IPUMS-created variable that sums individual income for family members (as opposed to households). You may want to review the documentation in FTOTINC and this information on families and income in ACS data for some context about the different definitions of families.

Your approach to limit your analysis to family households using HHTYPE = 1,2,3 sounds reasonable to me. Note that since the ACS is a sample survey, each household is weighted to represent multiple households in the population when calculating aggregate statistics. If you weight your analysis using HHWT, you should restrict your analytical sample to a single person per household (I recommend doing this using PERNUM = 1). If a household contains more than one family, however, this approach will not capture the second family’s unique value for FTOTINC because it only measures the income of a single family.