Each month during interview week, field representatives (FRs) and computer assisted telephone interviewers attempt to contact and interview a responsible person living in each sample unit selected to complete a Current Population Survey (CPS) interview. Typically, the week containing the 19th of the month is the interview week. The week containing the 12th is the reference week (i.e., the week about which the labor force questions are asked). In December, the week containing the 12th is used as interview week, provided the reference week (in this case the week containing the 5th) falls entirely within the month of December. In CPS, households are in sample for eight months. Each month, one-eighth of the households are in sample for the first time (month-in-sample 1 (MIS-1)), one-eighth for the second time, etc. Because of this schedule, different types of interviews (due to differing MIS) are conducted by each FR within his/her weekly assignment. An introductory letter is sent to each sample household prior to its 1st and 5th month interviews. The letter describes the CPS, announces the forthcoming visit, and provides respondents with information regarding their rights under the Privacy Act, the voluntary nature of the survey, and the guarantees of confidentiality for the information they provide. A personal visit interview is required for all first month-in-sample households because the CPS sample is strictly a sample of addresses. The U.S. Census Bureau has no way of knowing who the occupants of the sample household are, or even whether the household is occupied or eligible for interview. (Note: For some MIS-1 households, telephone interviews are conducted, if, during the initial personal contact, the respondent requests a telephone interview.)
The FR's first task is to establish the eligibility of the sample address for the CPS. There are many reasons an address may not be eligible for interview. For example, the address may have been converted to a permanent business, condemned or demolished, or it may be outside the boundaries of the area for which it was selected. Regardless of the reason, such sample addresses are classified as Type C noninterviews. The Type C units have no chance of becoming eligible for the CPS interview in future months, because the condition is considered permanent. These addresses are stricken from the roster of sample addresses and are never visited again with regard to CPS. All households classified as Type C undergo a full supervisory review of the circumstances surrounding the case before the determination is made final.
Type B ineligibility includes units that are intended for occupancy but are not occupied by any eligible individuals. Reasons for such ineligibility include a vacant housing unit (either for sale or rent), units occupied entirely by individuals who are not eligible for a CPS labor force interview (individuals with a usual residence elsewhere (URE) or in the Armed Forces). Such units are classified as Type B noninterviews. Type B noninterview units have a chance of becoming eligible for interview in future months, because the condition is considered temporary (e.g., a vacant unit could become occupied). Therefore, Type B units are reassigned to FRs in subsequent months. These sample addresses remain in sample for the entire eight months that households are eligible for interviews. Each succeeding month, an FR visits the unit to determine whether the unit has changed status, and either continues the Type B classification, revises the noninterview classification, or conducts an interview as applicable.
Additionally, one final set of households not interviewed for CPS are Type A households. These are households that the FR has determined are eligible for a CPS interview, but for which no useable data were collected. To be eligible, the unit has to be occupied by at least one person eligible for an interview (an individual who is a civilian, at least 15 years old, and does not have a usual residence elsewhere). Even though such households are eligible, they are not interviewed because the household members refuse, are absent during the interviewing period, or unavailable for other reasons. All Type A cases are subject to full supervisory review before the determination is made final. Every effort is made to keep such noninterviews to a minimum. All Type A cases remain in sample and are assigned for interview in all succeeding months. Even in cases of confirmed refusals (cases that still refuse to be interviewed despite supervisory attempts to convert the case) the FR must verify that the same household still resides at that address before submitting a Type A noninterview.
If the unit is not classified as a noninterview, the FR initiates the CPS interview. The FR attempts to interview a knowledgeable adult household member (known as the household respondent). The FRs are trained to ask the questions exactly as worded as they appear on the computer screen. The interview begins with the verification of the unit's address and confirmation of its eligibility for a CPS interview. Once this is established, the interview moves into the demographic portion of the instrument. The primary task of this portion of the interview is to establish the household's roster (the listing of all household residents at the time of the interview). At this point in the interview, the main concern is to establish an individual's usual place of residence. For all individuals residing in the household without a usual residence elsewhere, a number of personal and family demographic characteristics are collected.
These characteristics are the relationship to the reference person (the person who owns or rents the home), parent, spouse or cohab pointers (if applicable), age, sex, marital status, educational attainment, veteran's status, current Armed Forces status, race, and Hispanic origin. These characteristics are collected in an interactive format that includes a number of consistency edits embedded in the interview itself. The goal is to collect as consistent a set of demographic characteristics as possible. The final steps in this portion of the interview are to verify the accuracy of the roster. To this end, a series of questions is asked to ensure that all household members have been accounted for. Before moving on to the labor force portion of the interview, the FR is prompted to review the roster and all data collected up to this point. The FR has an opportunity to correct any incorrect or inconsistent information at this time. The instrument then begins the labor force portion of the interview.
In a household's initial interview, information about a few additional characteristics is collected after completion of the labor force portion of the interview. This information includes questions on family income and data on all household members' countries of birth (along with the countries of birth of his/her father and mother) and, for the foreign born, on year of entry into the United States and citizenship status.
After completing the household roster, the labor force data are collected from all civilian adult individuals (age 15 and older) who do not have a usual residence elsewhere. To the extent possible, the FR attempts to collect this information from each eligible individual him/herself. In the interest of timeliness and efficiency, however, a household respondent (any knowledgeable adult household member) often provides the data. Just over one-half of the CPS labor force data are collected by self-response. The bulk of the remainder is collected by proxy from the household respondent. Additionally, in certain limited situations, collection of the data from a nonhousehold member is allowed. All such cases receive direct supervisory review before the data are accepted into the CPS processing system.
For households in sample for the second, third, and fourth months, the FR has the option of conducting the interview over the telephone. Use of this interviewing mode must be approved by the respondent. Such approval is obtained at the end of the first month's interview upon completion of the labor force and any supplemental questions. Telephone interviewing is the preferred method for collecting the data; it is much more time and cost efficient. We obtain approximately 85 percent of interviews in these three months-in-samples (MIS) via the telephone. FRs must attempt to conduct a personal visit interview for the fifth-month interview. After one attempt, a telephone interview may be conducted provided the original household still occupies the sample unit. This fifth-month interview follows a sample unit's eight-month dormant period, and is used to reestablish rapport with the household. Fifth-month households are more likely than any other MIS households to be a replacement household, that is, a replacement household is one in which all the previous month's residents have moved out and been replaced by an entirely different group of residents. This can and does occur in any MIS except for MIS I households. As with their MIS 2, 3, and 4 counterparts, households in their sixth, seventh, and eighth MIS are eligible for telephone interviewing. Once again we collect about 85 percent of these cases via the telephone.
The first thing the FR does in subsequent interviews is update the household roster. The instrument presents a screen (or a series of screens for MIS 5 interviews) that prompts the FR to verify the accuracy of the roster. Since households in MIS 5 are returning to sample after an eight-month hiatus, additional probing questions are asked to establish the household's current roster and update some characteristics. If there are any changes, the instrument goes through the steps necessary to add or delete an individual(s). Once all the additions/deletions are completed, the instrument then prompts the FR/interviewer to correct or update any relationship items (e.g., relationship to reference person, marital status, and parent, spouse or cohab pointers) that may be subject to change. After making the appropriate corrections, the instrument will then take the interviewer to any items, such as educational attainment, that require periodic updating. The labor force interview in MIS 2, 3, 5, 6, and 7 collects the same information as the MIS I interview. MIS 4 and 8 interviews are different in several respects. Additional information collected in these interviews includes a battery of questions for employed wage and salary workers on their usual weekly earnings at their only or main job. For all individuals who are multiple jobholders, information is collected on the industry and occupation of their second job. For individuals who are not in the labor force, we obtain additional information on their previous labor force attachment.
Dependent interviewing is another enhancement made possible by the computerization of the labor force interview. Information collected in the previous month's interview is imported into the current interview to ease respondent burden and improve the quality of the labor force data. This change is most noticeable in the collection of main job industry and occupation data. Importing the previous month's job description into the current month's interview, shows whether an individual has the same job as he/she had the preceding month. Not only does this enhance analysis of month-to-month job mobility, it also frees the FR/interviewer from re-entering the detailed industry and occupation descriptions. This speeds the labor force interview and reduces respondent burden. Other information collected using dependent interviewing is the duration of unemployment (either job search or layoff duration), and data on the not-in-labor-force subgroups of retired and disabled. Dependent interviewing is not used in the MIS 5 interviews or for any of the data collected solely in MIS 4 and 8 interviews.
Another milestone in the computerization of the CPS is the use of centralized facilities for computer assisted telephone interviewing (CATI). The CPS has been experimenting with the use of CATI interviewing since 1983. The first use of CATI in production was the Tri-Cities Test, which started in April 1987. Since that time, more and more cases have been sent to CATI facilities for interviewing, currently numbering about 8000 cases each month. The facilities generally interview about 80 percent of the cases assigned to them. The net result is that about 12 percent of all CPS interviews are completed at a CATI facility.
Two CATI facilities are in use: Tucson, AZ and Jeffersonville, IN. One of the main reasons for using CATI is to ease the recruiting and hiring effort in hard to enumerate areas. It is much easier to hire an individual to work in the CATI facilities than it is to hire individuals to work as FRs in most major metropolitan areas, particularly in most large cities. Most of the cases sent to CATI are from the major metropolitan areas. CATI is not used in most rural areas because the small sample sizes in these areas do not cause the FRs undo hardship. A concerted effort is made to hire some Spanish speaking interviewers in the Tucson Telephone Center, enabling Spanish interviews to be conducted from this facility. No MIS I or 5 cases are sent to the facilities as explained above.
The facilities complete all but 20 percent of the cases sent to them. These uncompleted cases are recycled back to the field for follow-up and final determination. For this reason, the CATI facilities generally cease conducting the labor force portions of the interview on Wednesday of interview week, so that field staff has 3 to 4 days to check on the cases and complete any required interviewing or classify the cases as noninterviews. The field staff is highly successful in completing these cases as interviews, generally interviewing about 87-92 percent of the eligible cases. The cases that are sent to the CATI facilities are selected by the supervisors in each of the regional offices, based on the FR’s analysis of a household's probable acceptance of a CATI interview, and the need to balance workloads and meet specific goals on the number of cases sent to the facilities.