Retention and Reasons for Non-Interview

Retention and Reasons for Non-Interview

Mature Women Retention and Reasons for Non-Interview

Important Information

Researchers can use the 'Reason for Noninterview' variables to identify respondents who were dropped from the eligible sample. Respondents with a code of 12 were dropped due to missing two consecutive interviews for reasons other than death or refusal. It is more difficult to determine which respondents were dropped because they refused an interview in 1981 or earlier, because they are assigned the same code as respondents refusing an interview in later years. To identify these respondents, researchers must examine the 'Reason for Noninterview' variables and assume that a respondent was dropped if she has a code of 9 for every survey since she first refused, if that first refusal was in 1981 or earlier. Respondents who have consistently refused in later surveys, but who did not refuse an interview before 1982, remain in the eligible sample. Note that, because respondents are asked to report activities since the date of the last interview, most information from missed interviews was retrieved if the respondent was subsequently interviewed.

Eligible Sample and Reasons for Non-Interview

In general, respondents selected for interviewing each year were those who participated in the initial survey and who were alive, residing within the United States at the interview date, and noninstitutionalized. (Exception: In 2003, interviews were conducted with a few institutionalized respondents. See R65097.00-R65124.00.) If a respondent had joined the Armed Forces, she would also have been excluded from interview during her enlistment, but no Mature Women respondents were members of the military during the survey period. However, the criteria used to select the eligible sample--respondents whom the Census Bureau attempts to interview in a given round--have varied somewhat over the years.

Beginning in 1968, any respondent who had refused to be interviewed during a previous round was dropped from the eligible sample. Beginning in 1971, respondents were also dropped from the eligible sample if they had not been interviewed in two consecutive surveys for reasons other than death or refusal (for example, respondents who could not be located or contacted during the field period--those with 'Reason for Noninterview' codes of 1, 2, 3, 4, 5, 6, 8, or 11). In 1982, Census ceased dropping individuals for these two reasons but did not attempt to reinterview those already dropped. For example, a respondent who missed the 1979 and 1981 interviews, or any two consecutive interviews prior to that year, for a reason other than death or refusal was not eligible to participate in 1982 or any subsequent year. Similarly, a respondent who refused to participate in 1981 or any earlier survey was not eligible in 1982 or any later survey. However, respondents who refused to participate or missed their second consecutive interview in 1982 were retained in the sample and were eligible for all subsequent interviews, unless they died, were institutionalized, or obtained a Congressional refusal.

Table MW1 below depicts reasons for exclusion from the eligible sample and the years each applied.

Table MW1. Reasons for Exclusion from the Eligible Sample

Out-of-Scope Reason Years Exclusion Reason in Effect
Institutionalized All years. Exception: in 2003, interviewers made attempts
to interview respondents in institutions.
In the Armed Forces All years
Residing outside the U.S. All years
Deceased All years
Refusal during any one previous interview 1967-82. If interviewed in 1984, a respondent remained in
the eligible sample for subsequent interviews.
Dropped due to two consecutive noninterviews
for reasons other than refusal, death, or
membership in the Armed Forces
1971-82. If interviewed in 1984, a respondent remained
in the eligible sample for subsequent interviews.
Congressional Refusal1 1984-present
1 Congressional Refusal refers to a congressional representative requesting a respondent not be contacted again for the NLS after a respondent has completed one or more survey rounds.

Each survey year, NLS staff created a cumulative 'Reason for Noninterview' variable for the full sample of respondents. This created variable is a combination of (1) the noninterview reasons provided by Census for the subset of respondents designated as eligible for interview in that survey year and (2) the reason for noninterview assigned during a previous survey to out-of-scope respondents. For several surveys, CHRR released an additional variable reflecting the reasons for noninterview for only those respondents with whom interviews were attempted that year. This type of variable is available in 1974 (R07755.00) and in 1992 (e.g., R10093.00). The number of respondents that Census designated as eligible for interviewing fluctuated by survey year. The eligible sample can be identified by adding together the interviewed respondents and the respondents with a noninterview code in the original 'Reason for Noninterview' variables, those not marked 'Revised Deceased.'

Through the survey years there was concern that the number of respondents marked 'deceased' might be underreported and that some of the other 'Reason for Noninterview' categories might thus be overreported. In 2003, the Census Bureau, through the cooperation of the Social Security Administration, obtained SSA records for respondents who had shared their Social Security number with Census to verify whether respondents were living or deceased. As was previously suspected, a comparison of the SSA data with the survey data shows a substantially higher number of deceased respondents than was initially recorded.  To correct for past survey discrepancies, a revised 'Reason for Noninterview--Revised/Deceased' variable using the SSA data was created for each survey year from 1970 on. These revised variables are R01338.20, R02053.30, R02883.30, R03084.30, R03295.30, R04565.30, R04912.30, R05284.30, R06664.40, R07215.40, R07833.40, R08878.40, R10093.40, R16014.20, R34985.20, R42671.20, R63203.30, and R76154.00. Researchers are urged to use these updated variables rather than the original 'Reason for Noninterview' variables.

Instructions to interviewers on how to code a respondent's reason for noninterview appear within the Interviewer's Reference Manuals (or Field Representative's Manuals). The set of noninterview coding categories present during the initial survey years has been supplemented over the years with additional reasons for noninterview, and the meanings of existing categories have been refined. Table MW2 presents the raw coding categories present on the public data files and specifies the survey years during which each category was utilized.

Table MW2. Conceptual & Raw Coding Categories for the Reason for Noninterview Variables

Conceptual Category Raw Coding Category1 Code & Survey Years
CAN'T LOCATE Unable to locate [contact] R - reason not specified [1] All (1967-2003)
[Unable to locate R] - mover - no good address [4] All
INTERVIEW IMPOSSIBLE [Unable to locate R] - mover - good address given but interview impossible to obtain (e.g., "moved to Germany" or "lives too far from PSU - distance too great")2 [2] All
[Unable to locate R] - mover - good address given but unable to obtain interview after repeated attempts, etc. [3] All
[Unable to locate R] - nonmover - unable to obtain interview after repeated attempts, etc. [5] All
Temporarily absent [6] All
Other [11] All
REFUSAL Refusal [9] All
Congressional refusal3 [14] 1984-2003
OUT OF SCOPE In Armed Forces [7] All
Institutionalized [8] All4
Moved outside U.S. (other than Armed Forces) [13] 1979-2003
DECEASED Deceased [10] All
DROPPED Non-interview for two years, R dropped from sample [12] 1971-2003
1 Specific instructions to Census interviewers on use of these coding categories can be found in the cohort-specific Interviewer's Reference Manuals.
2 Beginning in the 1979 survey year, the separate "moved outside the U.S." coding category was added as a reason for noninterview and the "unable to locate" coding category no longer included those respondents who had moved outside the United States.
3 Congressional refusal refers to a congressional representative requesting a respondent not be contacted again for the NLS after a respondent has completed one or more survey rounds.
4 In 2003, interviewers sought out respondents in retirement communities, assisted living situations, and nursing homes.

The reason for noninterview coding categories depicted in Table MW3 below were constructed from the raw coding categories as shown in Table MW2. For example, the conceptual category "can't locate" is the sum of codes "1" and "4." Table MW3 depicts the count of non-interviewed by reason and survey year.

Table MW3. Reasons for Noninterview: 1968-2003

Survey Year Total
Total Not
Reason for Noninterview
Can't Locate Interview
Refusal Out of Scope1 Deceased Dropped2
1968 4910 173 49 25 76 1 22 --
1969 4712 371 50 69 210 7 35 --
1971 4575 508 56 65 294 6 58 29
1972 4471 612 39 49 390 2 71 61
1974 4322 761 41 31 481 5 100 103
1976 4172 911 34 40 581 7 131 118
1977 3964 1119 22 49 762 6 141 139
1979 3812 1271 21 27 866 11 183 163
1981 3677 1406 18 17 953 9 232 177
1982 3542 1541 14 26 1048 8 261 184
1984 3422 1661 30 25 1092 13 317 184
1986 3335 1748 37 35 1093 10 395 178
1987 3241 1842 30 45 1153 14 422 178
1989 3094 1989 29 49 1211 21 504 175
1992 2953 2130 60 18 1206 24 652 170
1995 2711 2372 68 89 1208 33 811 163
1997 2608 2475 94 49 1148 38 986 160
1999 2467 2616 78 67 1135 48 1131 157
2001 2318 2765 61 85 1078 55 1334 152
2003 2237 2846 36 47 1066 65 1485 147
Note: This table is based on R00856.00, R00884.00, R01338.20, R02053.30, R02883.30, R03084.30, R03295.30, R04565.30, R04912.30, R05284.30, R06664.40, R07215.40, R07833.40, R08878.40, R10093.40, R16014.20, R34985.20, R42671.20, R63203.30, and R76154.00
1 Beginning with the 1979 survey, "moved outside the U.S." became a separate out-of-scope coding category. Respondents who could not be interviewed during the 1968-77 surveys because their residence-either within or outside of the U.S.-was too far away were coded within the "interview impossible" category. Out-of-scope counts for pre-1979 survey years thus may be understated.
2 Respondents who had been noninterviews for two consecutive survey years due to reasons other than refusal or death were eliminated from the eligible sample beginning with the 1971 interview. After the 1982 interview, no additional respondents were dropped based on this rule. The number of respondents in this category has decreased steadily after 1982 due to the death rate of the respondents.

Sample Representativeness and Attrition

The retention rate for the Mature Women at the final interview was 44.0 percent, or 2,237 of the original 5,083 respondents. Retention rate  is defined as the percent of base-year respondents who were interviewed in any given survey year; included in the calculations are deceased and other out-of-scope respondents.  An analysis of selected characteristics of respondents interviewed in the tenth year samples of the Original Cohorts found that noninterviews had not seriously distorted the sample representativeness of any of the cohorts for the characteristics studied (Rhoton 1984). A second analysis of differential attrition among wealthy and non-wealthy subsamples of each of the four Original Cohorts found that non-wealthy respondents of each cohort showed a consistent tendency toward greater attrition (Rhoton and Nagi 1991). Among the three younger cohorts, almost all of the difference between wealthy and non-wealthy subsamples is accounted for by attrition reasons other than the death of the respondent. In a more recent analysis, Zagorsky and Rhoton (1998) concluded that respondents with lower socio-economic status attrited at a higher rate than those with higher income and educational attainment. Further, the authors found that white respondents were more likely to remain in the survey than blacks and those of other races. 

In Table MW4, the percentage of sampled respondents of each race is presented for the base survey year (1967) and the last interview year for which data is available. This table also provides information on numbers of deceased respondents by race.

Table MW4. Sample Characteristics by Race: 1967 and 2003

Race1 Number of Interviewed Respondents Retention
(2003 as % of 1967)
Number of Deaths
as of 20032
1967 2003
Non-black 3693 (72.7 %) 1693 (75.7%) 45.8 950
Black 1390 (27.3 %) 544 (24.3%) 39.1 535
1  See section on Race, Ethnicity & Nationality for details on race classifications. Respondent totals in this table are based on R00023.00.
2  Numbers are derived from R76154.00, a revised created variable that reflects mortality counts based on Social Security Administration records.


Rhoton, Patricia. "Attrition and the National Longitudinal Surveys of Labor Market Experience: Avoidance, Control and Correction." Columbus, OH: CHRR, The Ohio State University, 1984.

Rhoton, Patricia and Nagi, Karima. "Attrition by Wealth in the Original NLS Cohorts." Columbus, OH: CHRR, The Ohio State University, 1991.

Zagorsky, Jay and Rhoton, Pat. "Attrition and the National Longitudinal Surveys' Mature Women Cohort." Columbus, OH: CHRR, The Ohio State University, 1998.