Sampling Procedure
Because it is a longitudinal survey, the IFLS3 drew its sample from IFLS1, IFLS2, IFLS2+. The IFLS1 sampling scheme stratified on provinces and urban/rural location, then randomly sampled within these strata (see Frankenberg and Karoly, 1995, for a detailed description). Provinces were selected to maximize representation of the population, capture the cultural and socioeconomic diversity of Indonesia, and be cost-effective to survey given the size and terrain of the country. For mainly costeffectiveness reasons, 14 of the then existing 27 provinces were excluded. The resulting sample included 13 of Indonesia's 27 provinces containing 83% of the population: four provinces on Sumatra (North Sumatra, West Sumatra, South Sumatra, and Lampung), all five of the Javanese provinces (DKI Jakarta, West Java, Central Java, DI Yogyakarta, and East Java), and four provinces covering the remaining major island groups (Bali, West Nusa Tenggara, South Kalimantan, and South Sulawesi).
Household Survey:
Within each of the 13 provinces, enumeration areas (EAs) were randomly chosen from a nationally representative sample frame used in the 1993 SUSENAS, a socioeconomic survey of about 60,000 households. The IFLS randomly selected 321 enumeration areas in the 13 provinces, over-sampling urban EAs and EAs in smaller provinces to facilitate urban-rural and Javanese-non-Javanese comparisons.
Within a selected EA, households were randomly selected based upon 1993 SUSENAS listings obtained from regional BPS office. A household was defined as a group of people whose members reside in the same dwelling and share food from the same cooking pot (the standard BPS definition). Twenty households were selected from each urban EA, and 30 households were selected from each rural EA.This strategy minimized expensive travel between rural EAs while balancing the costs of correlations among households. For IFLS1 a total of 7,730 households were sampled to obtain a final sample size goal of 7,000 completed households. This strategy was based on BPS experience of about 90% completion rates. In fact, IFLS1 exceeded that target and interviews were conducted with 7,224 households in late 1993 and early 1994.
IFLS3 Re-Contact Protocols
The sampling approach in IFLS3 was to re-contact all original IFLS1 households having living members the last time they had been contacted, plus split-off households from both IFLS2 and IFLS2+, so-called target households (8,347 households-as shown in Table 2.1*) Main field work for IFLS3 went on from June through November, 2000. A total of 10,574 households were contacted in 2000; meaning that they were interviewed, had all members died since the last time they were contacted, or had joined another IFLS household which had been previously interviewed (Table 2.1*). Of these, 7,928 were IFLS3 target households and 2,646 were new split-off households. A 95.0% re-contact rate was thus achieved of all IFLS3 "target" households. The re-contacted households included 6,800 original 1993 households, or 95.3% of those. Of IFLS1 households, somewhat lower re-contact rates were achieved in Jakarta, 84.5%, and North Sumatra, 90.4%, but in some provinces such as West Nusa Tenggara re-contact rates were near universal, 99% (Table 2.2*). Of the contacted households, 10,435 households were actually interviewed in 2000. Of these, 3,774 are split-off households since IFLS1 and 6,661 are IFLS1 households (Table 2.2*). For users interested in panel data analysis, 6,564 households were interviewed in all three full waves of IFLS: 1, 2 and 3. That represents 90.9% of the original IFLS1 households interviewed. When one adds in the households that died since 1993, the fraction is 92.3%. The provincial distribution of contacted and interviewed households is shown in Table 2.2*.
As in 1997 and 1998, households that moved were followed, provided that they still lived in one the 13 provinces covered by IFLS, or in Riau. Likewise individuals who moved out of their IFLS households were followed. The rules for following individuals who moved out of an IFLS household were expanded in IFLS3. Target respondents for tracking were:
• 1993 main respondents,
• 1993 household members born before 1968,
• individuals born since 1993 in origin 1993 households, also in splitoff households if they are children of 1993 IFLS household members
• individuals born after 1988 if they were resident in an origin household in 1993,
• 1993 household members who were born between 1968 and 1988 if they were interviewed in 2000,
• 20% random sample of 1993 household members who were born between 1968 and 1988 if they were not interviewed in 1997.
NOTE: A detailed explanation of the whole sampling procedure including the re-contact protocols for IFLS1, IFLS 2+ and IFLS3 is available in the Overview and Field Report available under External Resources.
*See tables in User Guide Volume 1 (Overview and Field Report).
Community and Facility Survey:
The community-facility survey sought information about the communities of household respondents. We followed the procedures of IFLS2 to obtain most of our information, but added some new modules and one new book:
• The official village/township leader and a group of his/her staff were interviewed about aspects of community life. Supplementary information was obtained by interviewing the head of the community women's group, who was asked about the availability of health facilities and schools in the area, as well as more general questions about family health and prices of basic commodities in the community.
• In visits to local health facilities and schools, staff representatives were interviewed about the staffing, operation, and usage of their facilities.
• Data were extracted from community records, and data on prices were collected through visits to up to three markets or sales points in the community.
• As in IFLS2, we interviewed a social activist in the community about a project in which he or she was involved.
• We collected information on a set of social safety net programs that the Government of Indonesia initiated in 1998 to try to ameliorate negative impacts of the economic crisis, which began at the end of 1997. Some of this information we obtained from our usual sources described above, but in one case, for the health component, a new book was added to obtain information on the newly created national social safety net program for health (JPS/BK).Respondents for this book were generally the village midwife or a member of the local public clinic staff who was appointed to run the program for the community.
• Various information related to the new Regional Autonomy laws were also added to serve as a base line on the Decentralization Program that the government of Indonesia embarked upon in early 2001.
• Another new addition of IFLS3 was to interview the official village/township leader of the communities to which IFLS respondents had moved (different from the 312 original IFLS1 communities) to obtain a minimal amount of information on communities to which households had re-located. We collected information on factors such as total population, conditions of the village, access to the village, electricity availability, water and health service in the village and main sources of income.
To cover the major sources of public and private outpatient health care and school types, we defined six strata of facilities to survey:
• Government health centers and subcenters (puskesmas, puskesmas pembantu)
• Private clinics and practitioners including doctors, midwives, nurses, and paramedics (klinik,
praktek umum, perawat, bidan, paramedis, mantri)
• Community health posts (posyandu)
• Elementary schools (SD)
• Junior high schools (SMP)
• Senior high schools (SMU) / Senior vocational high schools (SMK)
IFLS3 used the same protocol for selecting facilities as IFLS1 and IFLS2. We wanted the specific schools and health providers for detailed interviews to reflect facilities available to the communities from which household respondents were drawn. Rather than selecting facilities based solely on information from the village leader or on proximity to the community center, we sampled schools and health care providers from information provided by household respondents. A difference with IFLS1 and IFLS2 was in the amount of household information available to construct sampling frames. In IFLS3, the tracking of households that moved to or near the EA (in the same village/ kecamatan) had been done during main survey instead of after. This enabled us to add facilities to the sample frame from locally- tracked households. This strategy was adopted since it was felt that the tracked household information would cover facilities in the EA.
Health Facility Sampling Frame. For each EA, we compiled a list of facilities in each health facility stratum from household responses about the names and locations of facilities the respondent knew about. Specifically, we drew on responses from book 1, module PP of the household survey, which asked (typically) the female household head if she knew of health facilities of various types, such as government health centers. The names and locations provided were added to the sampling frame.Household respondents did not need to have actually used a health facility for it to be relevant to the facility sample. Though someone in the household may well have used a facility that was mentioned, any facility known to the respondent was relevant. Requiring actual use of a facility was rejected because it was judged that that approach would yield a more limited picture of community health care options (since use of health care is sporadic) and possibly be biased by factors such as what illnesses were common around the time of the interview.
School Sampling Frame. Names of candidate schools were obtained from household responses to book K, module AR, in which (typically) the household head verified the name and location of all schools currently attended by household members under age 25. Therefore, unlike the health facility sampling frame, each school in the candidate list had at least one member of an IFLS household attending.
Final Samples. Not all identified health facilities and schools were eligible for interview. A facility was excluded if it had already been interviewed in another EA, if it was more than 45 minutes away by motorcycle. The facilities that were located in another area were eligible for interview so long it was in our reachable area (about 45 minutes away by motorcycle). We set a quota of facilities to be interviewed in each stratum in each EA. The goal was to obtain, for each stratum, data on multiple facilities per community. The quotas were different for different strata. For example, a larger quota was set for private practitioners than for health centers because Indonesian communities tend to have more private practitioners than health centers.
Stratum Quota per EA
Government Health centers and subcenters 3
Private clinics and practitioners 6
Community health posts 2
Elementary schools 3
Junior high schools 3
Senior high schools 2
Two forms were used in developing the facility sample for each stratum. Sample Listing Form I (SDI) provided space to tally household responses and ascertain which facilities met the criteria for interview and were not duplicates of each other. Those facilities constituted the sampling frame and were listed on the second form, Sample Listing Form II (SDII), in order of frequency of mention. The final sample consisted of the facility most frequently mentioned plus enough others, randomly selected, to fill the quota for the stratum. Note that because we sampled randomly from sample frames constructed by householder knowledge of facilities in 2000, we may not necessarily have re-sampled facilities that were sampled in IFLS1 or 2.
Social Activist Sampling Frame. Sampling was also used to identify the social activists to be interviewed. Three community projects that most involved and covered people in the community and that comprised our frame of projects were listed. One project was randomly selected and an activist who worked on that project was selected for interview. If it was not possible to interview or meet any activists of that project then the next project from the list was chosen. If the community was not currently running any project, past community projects that had ever been run were selected.