The NPS is nationally-representative household survey which provides measures of poverty, agricultural yields, and other key development indicators. The NPS is an “integrated” household survey, in that it covers a broad range of topics in the same questionnaire – from education and health to crime, gender-based violence and a range of other sections – to allow analysis of the links between sectors and the determinants of development outcomes.
The National Panel Survey (NPS) was designed to meet three principle objectives.
The first, overarching goals was to monitor progress toward the goals set out in the National Strategy for Growth and Poverty Reduction (aka, the MKUKUTA goals) and other national development objectives (MDG, PAF, etc.). The NPS provides high-quality, annual data on a long list of MKUKUTA indicators that is both nationally representative and comparable over time. As such, the NPS is intended to provide a key benchmark for tracking progress on poverty reduction and a wide range of other development indicators.
The second goal of the NPS is to facilitate better understanding of the determinants of poverty reduction in Tanzania. The NPS will enable detailed study of poverty dynamics at two levels. In addition to tracking the evolution of aggregate poverty numbers at the national level in years between Household Budget Surveys, the NPS will enable analysis of the micro-level determinants of poverty reduction at the household level. Panel data will provide the basis for analyzing the causal determinants of income growth, increasing or decreasing yields, improvements in educational achievement, and changes in the quality of public service provision over time by linking changes in these outcomes to household and community characteristics.
A third objective of the NPS is to provide data to evaluate the impact of specific policies and programs. With its national coverage and long time frame, the NPS will provide an ideal platform to conduct rigorous impact evaluations of government and non-government development initiatives. To achieve this goal, the National Bureau of Statistics will need to work in close collaboration with the relevant line ministries to link administrative data on relevant projects to changes in development outcomes measured in the survey.
Kind of data
Sample survey data [ssd]
Version 02 - "HH.Geovariables_Y1" dataset has been revised.
Version 03 - The community level data has been provided.
The survey covered all regions and all districts of Tanzania, both mainland and Zanzibar.
Producers and sponsors
National Bureau of Statistics
In order to monitor progress toward the MKUKUTA goals, it was vital that the NPS have a nationally-representative sample design. As such, in 2008/09 the NPS interviewed 3,280 households spanning all regions and all districts of Tanzania, both mainland and Zanzibar.
The sample size of 3,280 households was calculated to be sufficient to produce national estimates of poverty, agricultural production and other key indicators. It will also be possible in the final analysis to produce disaggregated poverty rates for 4 different strata: Dar es Salaam, other urban areas on mainland Tanzania, rural mainland Tanzania, and Zanzibar. Alternatively, estimates of most key indicators can be produced at the zone level, as used for the Demographic and Health Survey (DHS) reports and other surveys. There are 7 of these zones in total on the mainland: North, Central, Eastern, South, Southern Highlands, West and Lake. As with any survey though, the confidence of the estimates declines as statistics are disaggregated into smaller zones.
Due to the limits of the sample size it is not possible to produce reliable statistics at the regional or district level.
The guiding principle in the choice of sample size, following standard practice for NBS surveys, was to produce estimates with a 95% confidence interval no larger than 5% of the mean for key indicators. In this case, household consumption and maize yields were used as the basis for those calculations.
The NPS was based on a stratified, multi-stage cluster sample design. The principle strata were Mainland versus Zanzibar, and within these, rural versus urban areas, with a special stratum set aside for Dar es Salaam. Within each stratum, clusters were chosen at random, with the probability of selection proportional to their population size. In urban areas a 'cluster' was defined as a census enumeration area (from the 2002 Population and Housing Census), while in rural areas an entire village was taken as a cluster. This primary motivation for using an entire village in rural areas was for consistency with the HBS 2007 sample which did likewise.
Based on the 2002 Population and Housing Census, rural residents comprise roughly 77% of the population, compared with 63% of the NPS sample. The NPS sample gives slighter greater weight to urban areas due to the higher levels of inequality in these areas, and added difficulty in estimating poverty rates and other statistics. Similarly, Zanzibar comprised roughly 3% of the Tanzanian population in the 2002 census, but constitutes nearly 15% of the NPS sample, so as to allow separate Zanzibar-specific estimates to be presented for most indicators.
Finally, although it has been stressed that the 2008/09 round is the first year of the NPS, the sample design for year 1 was deliberately linked to the 2007 HBS to facilitate comparison between the surveys. On mainland Tanzania, 200 of the 350 in the NPS were drawn from the 2007 HBS sample (this included all 140 rural HBS clusters). Within these 200 HBS clusters, a portion of the (8) households sampled for the NPS were taken from the sample of (24) HBS households in the cluster. (The number of HBS households sampled varied from cluster to cluster, in proportion to the share of the population, as measured through a comprehensive household listing, that had remained stationary in the cluster since the time of the HBS. This was done to ensure that the NPS sample remained nationally representative despite possible non-random attrition of HBS households.)
This design created a panel of approximately 1,200 HBS households - interviewed in both the HBS and NPS - within the total sample of 3,280 NPS households.
Dates of collection
Mode of data collection
The main survey instrument of the NPS was the household questionnaire. This was administered to all households in the sample.
General household information – including food consumption and other household expenditure, which is central to poverty measurement – was solicited from the household head or another knowledgeable adult member of the household. In addition, wherever possible, each individual member over 5 years of age was interviewed directly for sections on education, health, labour, and food eaten outside the home.
In addition to the household questionnaire, a separate 46-page agricultural questionnaire was administered to all households with any agricultural activities (including farming, fishing or livestock, or ownership of any shamba even if not under cultivation). The agricultural questionnaire included detailed sections on each plot and each crop under cultivation, as well as information on farm assets, extension services, use and marketing of farm by-products, etc. For a sample of roughly 25% of the farming households, enumerators used GPS devices to directly measure the size of all farming plots.
Finally, apart from the questionnaires administered to households, a separate community questionnaire collected information from village, kitongoji and/or mtaa leaders. The community questionnaire covered topics including local administration and governance and access to basic services.
In a number of places, the NPS questionnaires provide extra detail relevant to MKUKUTA progress that goes beyond the specific indicators outlined in the MKUKUTA monitoring framework. In such cases, additional tables and statistics have been presented – in the relevant sections of the report – as a way of providing a deeper understanding of the process at work underlying progress on the core indicators. Key examples here are the enormous detail available on smallholder farming activities, which go far beyond the basic MKUKUTA indicators on technology usage and food production, and the in depth questions in the NPS on genderbased violence.
Tanzania National Bureau of Statistics
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National Bureau of Statistics. Tanzania National Panel Survey 2008-2009 (Round 1). Ref. TZA_2008_NPS-R1_v03_M. Dataset downloaded from http://microdata.worldbank.org on [date].
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