This is a 16-digit numeric variable.
HHID reports the household identifier in the original data.
Note that in datasets that include more than one diary per person and/or more than one person per household, HHID is not unique. Use IDENT to identify uniquely cases within a dataset and to link persons and activities records in hierarchical files.
- All persons.
- 1930, 1965, 1975, 1985, 1993, 1995, 1998