The 2020-21 Tanzania National Panel Survey (NPS) is the fifth round in a series of nationally representative household panel surveys that collect information on a wide range of topics including agricultural production, non-farm income generating activities, consumption expenditures, and a wealth of other socioeconomic characteristics. All four rounds of the NPS have been implemented by the Tanzania National Bureau of Statistics (NBS). The first round of the survey was conducted over twelve months, from October 2008 to September 2009. The main fieldwork of the second round of the NPS started in October 2010 and finished in September 2011, with specialized tracking teams remaining in the field until November 2011. Similarly, the duration and timing of the fieldwork for the third round of NPS was from October 2012 to November 2013. Fieldwork for the fourth round started in October 2014 and lasted until January 2016, while data collection for the fifth spanned December 2020 to January 2022.
The main objective of the NPS is to provide high-quality household-level data to the Tanzanian government and other stakeholders for monitoring poverty dynamics, tracking the progress of the Five Year Development Plan (FYDP) II poverty reduction strategy and its predecessor plans, and evaluating the impact of other major, national-level government policy initiatives. As an integrated survey covering a number of different socioeconomic factors, it compliments other more narrowly focused survey efforts, such as the Demographic and Health Survey (DHS) on health, the Integrated Labour Force Survey (ILFS) on labour markets, the Household Budget Survey (HBS) on expenditure, and the National Sample Census of Agriculture (NSCA). Secondly, as a panel household survey in which the same households are revisited over time, the NPS allows for the study of poverty and welfare transitions and the determinants of living standard changes.
Unit of Analysis
- v2.1: Edited, anonymous dataset for public distribution.
The 2020/21 NPS covers the following topics:
- HOUSEHOLD: Household identification; Survey staff details; Household member roster; Education, Health, Labour; Food outside the household; Subject welfare; Food security; Housing, water and sanitation; Consumption of food over the past one week; Non-food expenditures (past one week & one month); Non-food expenditures (past twelve months); Household assets; Family/household non-farm enterprises; Assistance and groups; Credit; Finance; Recent shocks to household welfare; Deaths in the household; Household re-contact information; Filter questions; Anthropometry.
- AGRICULTURE:Household roster; Plot roster; Plot details; Crops by plot; Crops - Household totals ( production and sales); Permanent crops by plot; Permanent crops - Household totals (production and sales); Input vouchers; Outgrower schemes and contract farming; Processed agricultural products and agricultural by-products; Farm implements and machinery extension; Extension.
- LIVESTOCK: Household member roster; Livestock stock; Animal health; Feed, water, housing, breeding; Livestock-labour; Milk; Animal power & dung; Other livestock products.
- COMMUNITY: Community identification; Survey staff details; Access to basic services; Investments projects; Land use; Demographics, land & livestock, Market prices; Local units.
Designed for analysis of key indicators at four primary domains of inference, namely:
Dar es Salaam,
Producers and sponsors
National Bureau of Statistics
Ministry of Finance and Planning
World Bank Living Standard Measurement Study Team
Bill and Melinda Gates Foundation
The NPS is based on a stratified, multi-stage cluster sample design which recognizes four analytical strata: Dar es Salaam, Other Urban areas in Mainland, Rural areas in Mainland, and Zanzibar. The sample design for the NPS 2020/21 targeted the sub-sample of households from the initial NPS 2014/15 cohort considered the “Refresh Panel”. These specific households had never previously been a part of the NPS sample design. This sample consisted of 3,352 households from 419 clusters in the NPS 2014/15 that were tracked and interviewed in the NPS 2020/21. An additional “Booster Sample” of 545 households from major cities and urban areas (specifically, Mbeya, Arusha, Mwanza, Tanga, and Dodoma) was also interviewed to allow for improved estimates in urban centres.
In previous NPS rounds, the sample design included complete households that could not be interviewed in a particular year but were found in later rounds, excluding those households that had refused to be interviewed (i.e. a household that was interviewed in Round 1, lost in Round 2, and found again in Round 3). This situation does not exist in the NPS 2020/21 as they have only been included in, at most, two rounds.
The eligibility requirement for inclusion of a household in this round of the NPS and all others is defined as any household having at least one member aged 15 years and above, excluding live-in servants. Households with at least one eligible member were completely interviewed, including any non-eligible members present in the household.
Additionally, the final sample for NPS 2020/21 included any split-off household or eligible members identified during data collection (i.e. a previous NPS member who had moved or started another household in between rounds). Marriage and migration are the most common reasons for households splitting over time. Ultimately, the final sample size for NPS 2020/21 was 23,592 individuals in 4,709 households. Of these, 4,164 households allow for panel analysis as they have been found and interviewed in both NPS 2014/15 and NPS 2020/21, while the remaining 545 (in the “Booster Sample”) will only have data available in the NPS 2020/21. The complete cohort interviewed in NPS 2020/21 will be maintained and tracked in all future waves of the NPS.
In order to produce nationally representative statistics with the NPS data, it is necessary to apply weighting or expansion factors. For previous rounds of the NPS, panel survey weights adjust for differences in the probability of selection into the NPS 2008/09 sample for observations in various strata, 2008/09 households splitting into multiple households in NPS 2010/11 and NPS 2012/13, splitting even further in NPS 2014/15, and attrition between rounds of the survey. A similar practice was used for panel survey weights in NPS 2020/21, based on their probability of selection in the NPS 2014/15 (as the Refresh Sample).
The first round of the NPS sample was a multi-stage clustered sample design. First stage sampling involved the selection of survey clusters with the probability of selection proportional to cluster size within a stratum. The sampling of these clusters was stratified along two dimensions: (i) eight administrative zones (seven on Mainland Tanzania plus Zanzibar as an eighth zone), and (ii) rural versus urban clusters within each administrative zone. The combination of these two dimensions yields 16 strata. In rural areas a cluster is defined as an entire village. In urban areas, a cluster is defined as a census enumeration area. As a general rule, the probability of selection was higher for clusters within strata where existing data sources showed that the variance of key variables of interest for the NPS (e.g., household consumption and maize production) were likely to be very high – implying the need for more observations to produce reliable estimates.
The expansion factors for the NPS 2020/21, variables y5_panelweight and y5_crossweight, have been integrated into Section A in the household dataset (“HH_SEC_A.dta”). The former is only available for the set of households that were a part of the NPS 2014/15 sample, while the latter provides a weight for the full cross-section of households collected in NPS 2020/21, regardless of whether they are a part of the panel or booster sample. Additionally, unique identifiers for the first-stage sampling units, clusterid, and for the sampling strata, strataid can also be found in the Section A in the household datasets.
Dates of Data Collection
Data Collection Mode
Computer Assisted Personal Interview [capi]
Data Collection Notes
The main training for the field team supervisors and enumerators took place in Iringa region in November-December, 2020 over a period of thirty (30) days. During this time, the field staff spent one week on the Household Questionnaire, a week for Agricultural Questionnaire, and a week on the Livestock Questionnaire, and tracking forms. The last week of the training was devoted to field practice. Field practice were conducted in Iringa regions, where selected households from the previous rounds of the NPS were revisited to provide the team enumerators and supervisors practice with conducting tracking during fieldwork. After the fieldwork, extensive discussion and revisions were conducted with the participation of all team supervisors.
Over the training period, three tests were administered to the field teams. The goal was to gain feedback from the training sessions and to select the qualified enumerators. Overall, there were 54 enumerator candidates, with all the enumerators being selected. Interviewer manuals were developed with detailed instructions for field staff during training and as the main reference guide for the survey over the course of the fieldwork. At the end of the training, the enumerators were each provided with an interviewer manual in Kiswahili.
Fieldwork for the NPS 2020/21 began in the last week of December 2020 and was completed in January 2022. This 14-month span of fieldwork addresses any intra-year seasonality concerns and fluctuations. The survey was primarily implemented by eight mobile field teams, each composed of: one supervisor, seven enumerators, and one driver. Seven mobile field teams were responsible for different regions on the mainland and one team was responsible for all of Zanzibar.
Field teams visited each cluster for between 2-3 days for both panel and booster clusters. The questionnaires were administered to the selected households over the course of that time. This allowed the field team to make return visits to the household to complete the entire Household Questionnaire, Agriculture Questionnaire for farming households, and Livestock Questionnaire for households engaged in livestock activities. To ensure the depth and quality of each section of the survey, the questionnaire was administered across multiple respondents and to members most knowledgeable about each topic. For all the sampled tracking households, areas of all owned and/or cultivated agricultural plots were measured via GPS unless the household refused, the terrain was too difficult, or if the plot was more than one (1) hour drive from the location of the household. Anthropometric measurements were taken for all eligible individuals that were at home, not too ill, and willing to participate.
Tracking consisted of three stages: (1) determining the current status of the households and members of the households from the previous survey; (2) determining the location of any households that have moved together with all its members to a new location; and (3) determining the location of any eligible members who have moved from their household from either or all rounds of the NPS to a new location. Eligibility for tracking of households and members was determined prior to the implementation of the survey. Members eligible for tracking were those over the age of 15 and who are not a live-in house servant. Any members not meeting this criterion was not tracked and were only included in the data when located and interviewed with an eligible member. Furthermore, households eligible for tracking must have moved to a new location within Tanzania. If a household moved to a different country, it was not tracked.
If an entire household had moved from the original residence, teams were required to complete a “T-1” form designed to capture relevant information from key informants on the whereabouts of the household. The T-1 form contains information that would enable tracking of household to its new location. If a member or members of the household have moved from the original household, a “T-2” form was completed by the teams. Similar to the T-1 form, a T-2 form contains information on the location of the member(s) who have moved from the household. Once the tracking targets had been located, teams were required to interview the household as consistent with the eligibility requirements.
Within the tracking protocol, there are local and distance tracking cases. Local and distance tracking applies to both households and individuals. Local tracking is defined as cases where the tracking target is within one hour driving distance from the original cluster and at least one tracking member from the household is eligible for tracking. For local tracking cases, the teams are required to interview the tracking target before leaving the original cluster. Distance tracking occurs when the tracking target resides in a location that is more than one hour drive from the original cluster. In this case, the teams fill out the appropriate tracking form and send the information to NBS headquarters. Once at NBS headquarters, the distance tracking case is given to one of the field teams based on the location of the new residence of the household or individual, this assigned field team is then responsible for locating that household and conducting the interview.
Often households and members who have moved from their previous dwelling or household have relocated a great distance from their previous interview location. Given the inefficiency in searching for these members on a case-by-case basis across the country as they occur, field teams were not required to track households and members deemed to be too far away from the original location. Information on these cases was entered and sent electronically to the NBS headquarters, for compilation and review. After review, the tracking cases were assigned to the field teams based on the location of the new residence of the household or individual.
Distance tracking was done after the completion of the main data collection to allow enough time to accumulate a sufficient number of distance tracking targets. Furthermore, regular field teams would perform distance tracking whenever they had a break in their schedule. Three dedicated teams of four enumerators conducted the distance tracking fieldwork.
Data Processing & Management:
The NPS 2020/21 contains a robust multi-level quality assurance and data management system. Great effort was placed on the development and utilization of this system by the NBS with technical assistance form the World Bank prior to the implementation of the NPS 2020/21 to assist in the management of the complex household panel survey and address the growing need for high quality timely data.
The NPS 2020/21 utilized a Survey Solutions Computer Assisted Personal Interviewing (CAPI) system developed by the Word Bank in collaboration with IT personnel from the NBS. This system was selected to increase the availability of data for review by managing staff as well as to provide regular and consistent quality assessment of data directly to the field staff. STATA software was utilized to perform complex aggregated checks. Furthermore, due to the panel nature of the survey, where applicable and appropriate, data was checked against previous round data.
Data files from completed clusters were transmitted to NBS headquarters via syncing to the Survey Solutions server using 3G USB modems. Received data files were downloaded at the headquarters, and regular checks performed to ensure the fieldwork was proceeding according to the schedule and that quality standards were met. During the course of field work, data was routinely checked at the aggregate level to identify any potential issues and where identified, additional checks were integrated into the CAPI and Stata systems.
Throughout the data processing, system versions of the data are archived at all key steps and all checking and cleaning syntax documented and archived
The NPS 2020/21 consists of four survey instruments: a Household Questionnaire, Agriculture Questionnaire, Livestock Questionnaire, and a Community Questionnaire. A detailed description of the questionnaires is provided in the Survey Instruments section of the Basic Information Document (available under Downloads). All questionnaires are in English and available for download.
National Bureau of Statistics
Living Standards Measurement Study (LSMS)
The Primary Data Investigator undertakes that no attempt will be made to identify any individual person, family, business, enterprise or organization. If such a unique disclosure is made inadvertently, no use will be made of the identity of any person or establishment discovered and full details will be reported to the NBS. The identification will not be revealed to any other person not included in the Data Access Agreement.
Use of the dataset must be acknowledged using a citation which would include:
- the Identification of the Primary Investigator
- the title of the survey (including country, acronym and year of implementation)
- the survey reference number
- the source and date of download
National Bureau of Statistics (Ministry of Finance and Planning). Tanzania - National Panel Survey 2020-21, Wave 5, Wave 5 (). Ref: TZA_2020_NPS-R5_v02_M. Downloaded from [uri] on [date].
National Bureau of Statistics
Living Standards Measurement Study (LSMS)
Disclaimer and copyrights
The user of the data acknowledges that the original collector of the data, the authorized distributor of the data, and the relevant funding agency bear no responsibility for use of the data or for interpretations or inferences based upon such uses.