FAMINC includes income of all household members?

The IPUMS CPS variable description for FAMINC notes:

FAMINC reports annual family income, in categories, of all persons related to the head of household/householder. For individuals who are not part of the householder’s family, FAMINC reports the value for the householder’s family. This measure includes the income of all members of the household who are 15 years of age or older…At the end of the monthly labor force survey, respondents are asked to choose the category that represents the total combined income during the past 12 months for all members of the householder’s family.

Meanwhile, the description for HHINCOME notes:

HHINCOME reports the total money income during the previous calendar year of all adult household members. The amount should equal the sum of all household members’ individual incomes as recorded in the IPUMS-CPS variable INCTOT. The persons included were those present in the household at the time of the survey. People who lived in the household during the previous year but were not still living there at the time of the survey are not included; household members who lived elsewhere during the previous year but had joined the household at the time of the survey are included.

Clear differences between these descriptions are:

  • FAMINC is the respondent’s response while HHINCOME is generated from component responses.
  • HHINCOME includes only “adult” (undefined) household members while FAMINC includes those 15+
  • Unlike HHINCOME, FAMINC may exclude (include) income of family members (not) present in the household at the time of the survey.
  • HHINCOME is a continuous measure while FAMINC is a categorical response

However, I am finding the bolded text for FAMINC. While FAMINC is supposed to capture family income, the text clearly states it reflects income of members of the household aged 15 and over. Since not all household members need to be family members, it’s not clear what FAMINC is actually measuring given the first and third sentences of the FAMINC description seem in conflict.

Can someone clarify what is actually reflected in FAMINC and how it relates to households versus families? I have read the previous posts on here, but none address the point that the description explicitly states the family income variable includes incomes of all household members. If the text instead stated it included all members of the family 15+, it would make more sense.

Similarly, should FAMINC be identical within all observations for a given household identifier (i.e. the concatenation of YEAR and SERIAL) or only within a given family identifier (i.e. the concatenation of YEAR, SERIAL, and FAMID)?

You are correct about FAMINC being a specific response on the CPS questionnaire and HHINCOME being the sum of INCTOT for all household members. The note about HHINCOME being the sum of all “adult” household members comes from the universe for INCTOT, which (since 1980) includes only those age 15 and older. HHINCOME is defined as the sum of INCTOT for all individuals within the household. The means that individuals not in the household at the time of the survey will not be included in the sum of HHINCOME. FAMINC may include income from family members not in the household at the time of the survey, but this will depend on the respondent’s judgement. Finally, HHINCOME is a continuous measure of income and FAMINC provides income categories.

You are also correct that not all household members are necessarily family members. This is what the FAMINC variable tries to identify. It asks the householder (e.g., the person filling out the survey), to report the total income of each member of their family. For those individuals who are not a member of the householder’s family, their income is not counted in the calculation of FAMINC. With that said, FAMINC is a “household level” variable and so all members of the same household will have the same value for FAMINC. Individuals not a member of the householder’s family have the householder’s family income for their observation in the FAMINC variable.