IFSS_CMBIRTH: Century month of R's birth
|Summary for Variable Group: Sociodemographic characteristics|
|The variables in this group describe the respondent's marital status, age, racial and ethnic background, religion, attitudes, region of residence, and farm experience. In addition, the unique identifier variable is included in this group. Information related to the respondent's education is described in the "Education" variable group.
|Century month of R's birth|
|1976 NSFG: Couple File|
|A7_CM||M_A-7||1976 NSFG: Couple File|
|IFSS_CMBIRTH is the century month of birth for the respondent. It is calculated from the reference period 1900.
General Comparability Notes
Summary: Data harmonized into IFSS_CMBIRTH was collected in one of two ways: either from the household screener or as a direct question in the questionnaire. Date of birth was computed for the 1955 GAF. Respondent universe is completely comparable and includes all respondents over time.
There is some variability in the source of the underlying variable. For all of the surveys in the NSFG series (1973 forward), the variables are constructed from actual questions asked of the respondent. Through 1988, the question was asked as "When were you born (month and year)?" In 1995 and 2002, the question wording was slightly different. These two surveys asked, "What is the date of your birth?" with no clarification or instruction on month or year. In 1982, the information about date of birth was obtained from the household screener, which the interviewer used to determine sampling eligibility. In 1988, the interviewer instructions suggest that this information is gathered in a screener because the question is preceded by "Ask or Confirm." The respondent is also asked for month and day of birth in 1955 and two variables were created, which are then transformed to create century months. In the NFS and GAF series, date of birth is not asked directly, but by a household screener or coversheet. In 1970, there is no direct evidence of the source of the variable, but it is assumed to be from the household screener.
Imputation Flag Exists
|Imputation Flag Values|
|1||Imputed in original study|
|3||Month imputed (Original file edit)|
|4||Age known, month imputed|
|5||Originally imputed as June, recoded to random month|
|7||Multiple regression imputed: Not ascertained|
|8||Multiple regression imputed: Refused|
|9||Multiple regression imputed: Don't know|
|10||Midpoint of a given range|
|11||Answer comes from a follow-up question|
|12||Midpoint of a range given as a follow-up|
|13||Answer is rounded up|
|14||Answer is rounded down|
|15||Reported months and weeks, weeks<=4|
|17||Reported months=weeks & weeks>4|
|18||Reported months!=trunc(weeks/4.35), months!=weeks, weeks>4|
|19||Months coded NA/RF/DK|
|20||Weeks coded NA/RF/DK|
|21||Impossible to determine which method used last|