Agriculture Sample Census Survey 2002-2003
Tanzania, 2004
Get MicrodataIdentification
TZA-NBS-ASCC-2002-v01
Agriculture Sample Census Survey 2002-2003
| Name | Country code |
|---|---|
| Tanzania | TZA |
Agricultural Census [ag/census]
This is the third Agriculture Census to be carried out in Tanzania, the first one was conducted in 1971/1972, the second in 1993/1994 and 1994/1995(during1993/95 data on household characteristics and livestock count were collected and data on crop area and production in 1994/95). It considered that, this census is is one of the largest to be carried out in Africa and in many other countries of the world.
The 2003 Agriculture Sample Census was designed to meet the data needs of a wide range of users down to district level including policy makers at local, regional and national levels, rural development agencies, funding institutions, researchers, NGOs, farmer organisations, etc. As a result the dataset is both more numerous in its sample and detailed in its scope compared to previous censuses and surveys. To date this is the most detailed Agricultural Census carried out in Africa. The census was carried out in order to:
· Identify structural changes if any, in the size of farm household holdings, crop and livestock production, farm input and implement use. It also seeks to determine if there are any improvements in rural infrastructure and in the level of agriculture household living conditions;
· Provide benchmark data on productivity, production and agricultural practices in relation to policies and interventions promoted by the Ministry of Agriculture and Food Security and other stake holders.
· Establish baseline data for the measurement of the impact of high level objectives of the Agriculture Sector Development Programme (ASDP), National Strategy for Growth and Reduction of Poverty (NSGRP) and other rural development programs and projects.
· Obtain benchmark data that will be used to address specific issues such as: food security, rural poverty, gender, agro-processing, marketing, service delivery, etc.
Sample survey data [ssd]
Household, Individual
Version
Version 01(Public use file for web dissemination)
2004-03
Scope
The census covered agriculture in detail as well as many other aspects of rural development and was conducted using three different questionnaires:
·Small scale farm questionnaire
·Community level questionnaire
·Large scale farm questionnaire
| Topic | Vocabulary | URI |
|---|---|---|
| TRADE, INDUSTRY AND MARKETS [2] | CESSDA | http://www.nesstar.org/rdf/common |
Coverage
Tanzania Mainland and Zanzibar
Clusters
Small scale farmers, Large Scale Farmers, Community Level
Producers and sponsors
| Name | Affiliation |
|---|---|
| National Bureau of Statistics | Ministry of Planning and Empowerment |
| Office of Chief Government Statistician-Zanzibar | Ministry of Finance and Economic Affairs |
| Name | Role |
|---|---|
| Ministry of Agriculture and Food Security | Technical assistance |
| Ministry of Water and Livestock Development | Technical assistance |
| Ministry of Cooperatives and Marketing | Technical assistance |
| Presidents Office, Regional Administration and Local Government | Technical assistance |
| Ministry of Finance and Economic Affairs | Technical assistance |
| Food and Agriculture Organisation | Technical assistance |
| Name | Role |
|---|---|
| Tanzania Government | Financial support |
| United Nation Development Program | Financial support |
| Department for International Development | Financial support |
| Japan Government | Financial support |
| European Union | Financial support |
| Name | Affiliation | Role |
|---|---|---|
| Planning group | Agriculture Statistics Department-NBS | Planning and Supervision of the Survey |
| Ultec Lawrence Gould | Technical assistance | |
| Scotts Agriculture Consultancy LTD | Technical assistance |
Sampling
The Mainland sample consisted of 3,221 villages. These villages were drawn from the National Master Sample (NMS) developed by the National Bureau of Statistics (NBS) to serve as a national framework for the conduct of household based surveys in the country. The National Master Sample was developed from the 2002 Population and Housing Census. The total Mainland sample was 48,315 agricultural households. In Zanzibar a total of 317 EAs were selected and 4,755 agriculture households were covered. Nationwide, all regions and districts were sampled except three urban district (two from Mainland and one from Zanzibar).
In both Mainland and Zanzibar, a stratified two stage sample was used. The number of villages/Enumeration Areas (EAs) were selected for the first stage with a probability proportional to the number of villages in each district. In the second stage, 15 households were selected from a list of farming households in each Village/EA using systematic random sampling. Table 1.1 gives the sample size of households, villages and districts for Tanzania Mainland and Zanzibar.
1.3.4 Questionnaire Design and Other Census Instruments
The questionnaires were designed following user meetings to ensure that the questions asked were in line with users data needs. Several features were incorporated into the design of the questionnaires to increase the accuracy of the data:
· Where feasible all variables were extensively coded to reduce post enumeration coding error.
· The definitions for each section were printed on the opposite page so that the enumerator could easily refer to the instructions whilst interviewing the farmer.
· The responses to all questions were placed in boxes printed on the questionnaire, with one box per character. This feature made it possible to use scanning and Intelligent Character Recognition (ICR) technologies for data entry.
· Skip patterns were used to reduce unnecessary and incorrect coding of sections which do not apply to the respondent.
· Each section was clearly numbered, which facilitated the use of skip patterns and provided a reference for data type coding for the programming of CSPro, SPSS and the dissemination applications.
Three other instruments were used:
· Village Listing Forms were used for listing households in the village and from this list a systematic sample of 15 agricultural households were selected.
· A Training Manual which was used by the trainers for the cascade/pyramid training of supervisors and enumerators
· Enumerator Instruction Manual which was used as reference material.
1.3.5 Field Pre-testing of the Census Instruments
The Questionnaire was pre-tested in five locations (Arusha, Dodoma, Tanga, Unguja and Pemba). This was done to test the wording, flow and relevance of the questions and to finalise crop lists, questionnaire coding and manuals. In addition to this, several data collection methodologies had to be finalised, namely, livestock numbers in pastoralist communities, cut flower production, mixed cropping, use of percentages in the questionnaire and finalising skip patterns and documenting consistency checks.
The weight for Agriculture sample Census Survey 2002-2003 found in Technical Report from page (17) to page (20)
Survey instrument
The census covered agriculture in detail as well as many other aspects of rural development and was conducted using three different questionnaires:
· Small scale farm questionnaire
· Community level questionnaire
· Large scale farm questionnaire
The small scale farm questionnaire was the main census instrument and includes questions related to crop and livestock production and practices; population demographics; access to services, resources and infrastructure; and issues on poverty, gender and subsistence versus profit making production units. The main topics covered were:
· Household demographics and activities of the household members
· Land access/ownership/tenure and use
· Crop and livestock production and productivity
· Access to inputs and farming implements
· Access and use of credit
· Access to infrastructure (roads, district and regional headquarters, markets, advisory services, schools, hospitals, veterinary clinics, etc...)
· Crop marketing, storage and agro processing
· Tree farming, agro-forestry and fish farming
· Access and use of communal resources (grazing, communal forest, water for humans and livestock, beekeeping etc.)
· Investment activities: Irrigation structures, water harvesting, erosion control, fencing, etc.
· Off farm income and non agriculture related activities
· Households living conditions (housing, sanitary facilities, etc.)
· Labour use, livelihood constraints and subsistence versus non subsistence activities
· Gender issues.
The community level questionnaire was designed to collect village level data such as access and use of common resources, community tree plantations and seasonal farm gate prices.
The large scale farm questionnaire was administered to large farms which were either privately or corporately managed. Some data from the large scale farm questionnaire are incorporated in this report, however an in depth analysis of large scale farms is presented in a separate report.
Data collection
| Start | End |
|---|---|
| 2004-01 | 2004-03 |
- Face-to-face [f2f]
| Name | Affiliation |
|---|---|
| National Bureau of Statistics | Ministry of Planning and Empowerment |
Enumerators were trained to probe the respondents until they were satisfied with the responses given before they recorded them in the questionnaire. The first check of the questionnaires was done by enumerators in the field during enumeration. The second check was done by the district supervisors followed by Regional and National Supervisors. Supervisory visits at all levels of supervision focused on consistency checking of the questionnaires. Inconsistencies encountered were corrected, and where necessary a return visit to the respondent was made by the enumerator to obtain the correct information. Further quality control checks were made through a major post enumeration checking exercise where all questionnaires were checked for consistencies by supervisors in the district offices.
Data collection activities for the 2002/03 Agriculture Sample Census took three months from January to March 2004. The data collection methods used during the census was by interview only. No physical measurements, e.g., crop cutting and field area measurement, were taken. Field work was monitored by a hierarchical system of supervisors at the top of which was the Mobile Response Team followed by the Regional Supervisors and District Supervisors. The Mobile Response Team consisted of three Principal Supervisors who provided overall direction to the field operations and responded to queries raised outside the scope of the training exercise. The mobile response team consisted of the Manager of Agriculture Statistics Department, Long-term Consultant and the Desk Officer for the Census. Decisions made on definitions and procedures were then communicated back to all enumerators via the Regional and District Supervisors.
On the Mainland district supervision and enumeration were done by staff from the President's Office, Regional Administration and Local Government (PORALG). Regional and national supervision was provided by senior staff of the National Bureau of Statistics and the sector ministries of agriculture. In Zanzibar the enumeration was done by staff from the Ministry of Agriculture, Natural Resources, Environment and Cooperatives. Supervision was provided by senior officers of the same ministry and the Office of the Chief Government Statistician.
During the household listing exercise, 3,222 extension staff were used on the Mainland and 317 in Zanzibar. For the enumeration of the small holder questionnaire, 1,611 enumerators on Mainland and 158 in Zanzibar were used. An additional five percent of the total number of enumerators was held in reserve in case of drop outs during the enumeration exercise.
1.3.9 Field Supervision and Consistency Checks
Enumerators were trained to probe the respondents until they were satisfied with the responses given before they recorded them in the questionnaire. The first check of the questionnaires was done by enumerators in the field during enumeration. The second check was done by the district supervisors followed by Regional and National Supervisors. Supervisory visits at all levels of supervision focused on consistency checking of the questionnaires. Inconsistencies encountered were corrected, and where necessary a return visit to the respondent was made by the enumerator to obtain the correct information. Further quality control checks were made through a major post enumeration checking exercise where all questionnaires were checked for consistencies by supervisors in the district offices.
Data processing
Data processing consisted of the following processes:
· Data entry
· Data structure formatting
· Batch validation
· Tabulation
Data Entry
Scanning and ICR data capture technology for the small holder questionnaire were used on the Mainland. This not only increased the speed of data entry, it also increased the accuracy due to the reduction of keystroke errors. Interactive validation routines were incorporated into the ICR software to track errors during the verification process. The scanning operation was so successful that it is highly recommended for adoption in future censuses/surveys. In Zanzibar all data was entered manually using CSPro.
Prior to scanning, all questionnaires underwent a manual cleaning exercise. This involved checking that the questionnaire had a full set of pages, correct identification and good handwriting. A score was given to each questionnaire based on the legibility and the completeness of enumeration. This score will be used to assess the quality of enumeration and supervision in order to select the best field staff for future censuses/surveys.
CSPro was used for data entry of all Large Scale Farm and community based questionnaires due to the relatively small number of questionnaires. It was also used to enter data from the 2,880 small holder questionnaires that were rejected by the ICR extraction application.
Data Structure Formatting
A program was developed in visual basic to automatically alter the structure of the output from the scanning/extraction process in order to harmonise it with the manually entered data. The program automatically checked and changed the number of digits for each variable, the record type code, the number of questionnaires in the village, the consistency of the Village ID Code and saved the data of one village in a file named after the village code.
Batch Validation
A batch validation program was developed in order to identify inconsistencies within a questionnaire. This is in addition to the interactive validation during the ICR extraction process. The procedures varied from simple range checking within each variable to the more complex checking between variables. It took six months to screen, edit and validate the data from the smallholder questionnaires. After the long process of data cleaning, tabulations were prepared based on a pre-designed tabulation plan.
Tabulations
Statistical Package for Social Sciences (SPSS) was used to produce the Census tabulations and Microsoft Excel was used to organize the tables and compute additional indicators. Excel was also used to produce charts while ArcView and Freehand were used for the maps.
Analysis and Report Preparation
The analysis in this report focuses on regional comparisons, time series and national production estimates. Microsoft Excel was used to produce charts; ArcView and Freehand were used for maps, whereas Microsoft Word was used to compile the report.
Data Quality
A great deal of emphasis was placed on data quality throughout the whole exercise from planning, questionnaire design, training, supervision, data entry, validation and cleaning/editing. As a result of this, it is believed that the census is highly accurate and representative of what was experienced at field level during the Census year. With very few exceptions, the variables in the questionnaire are within the norms for Tanzania and they follow expected time series trends when compared to historical data. Standard Errors and Coefficients of Variation for the main variables are presented in the Technical Report (Volume I).
Data appraisal
The Sampling Error found on page (21) up to page (22) in the Technical Report for Agriculture Sample Census Survey 2002-2003
Data Access
| Name | Affiliation | URL | |
|---|---|---|---|
| National Bureau of Statistics | Ministry of Planning and Empowerment | www.nbs.go.tz | info@nbs.go.tz |
| Is signing of a confidentiality declaration required? | Confidentiality declaration text |
|---|---|
| yes | Confidentiality of respodents is guaranteed by section 20 of Tanzania Statistics act number 1 of 2002 Before being granted access to the dataset, all users have formally agree: 1.all identifying information such as the name and address of respondent has been removed; and 2.the information is disclosed in a manner that is not likely to enable the identification of the particular person or undertaking or business to which it relates. 3.not attempt to identify any particular person or undertaking or business; 4.use of information for research or statistically purpose only; 5.not to disclose the information to any other person, organization 6.when required by the Director General, return all documents made available to him to the Director General; 7.comply with the directions given by the Director General relating to the records. 8.every person involved in the research or statistical project for which information is disclosed pursuant to this section shall make the declaration of secrecy set out in the first schedule. |
Tanzania NBS considered three levels of accessibility:
- Public use files, accessible by all
- Licensed datasets, accessible under certain conditions
- Datasets only accessible on location, for certain datasets
The dataset has been anonymized and available as a public use dataset. It accessible to all for statistical and research purposes only, under the following terms and conditions:
1.The data and other material will not be redistributed or sold to other individuals, institutions, or organization without the written agreement of the National Bureau of Statistics.
2.The data will be used for statistical and scientific research purposes only. They will be used solely for reporting of aggregated information, and not for investigation of specific individuals or organizations.
3.No attempt will be made to produce links among dataset provided by the National Bureau of Statistics, or among data from the (National Bureau of Statistics) and other datasets that could identify individuals or organizations
4.No attempt will be made to re-identify respondents, and no use will be made of the identify of any person or establishment discovered inadvertently. Any such discovery would immediately be reported to the National Bureau of Statistics.
5.Any books, articles, conference papers, theses, dissertations, reports, or other publications that employ data obtained from the National Bureau of Statistics will cite the source of data in accordance with the Citation Requirement provided with each dataset.
"National Bureau of Statistics, Agriculture Sample Census Survey 2002-2003(AGRSCS 2002-2003), version 1.0 of the public use dataset(March 2004) provided by the National Bureau of Statistics, www.nbs.go.tz"
Disclaimer and copyrights
"The user of the data should acknowledges that, National Bureau of Statistics is the original collector of the data , the authorised distributor of the data, and the relevant funding agency bear no responsibility for use of the data or for interpretations or inferences without a written agreement from the National Bureau of Statistics"
(c) 2002, National Bureau of Statistics
Contacts
| Name | Affiliation | URL | |
|---|---|---|---|
| Director General | National Bureau of Statistics | dg@nbs.go.tz | www.nbs.go.tz |
Metadata production
TZA-NBS-AGRSCS-2002-2003v01
| Name | Affiliation | Role |
|---|---|---|
| National Bureau of Statistics | Ministry of Planning and Empowerment | Data Producer |
| Office of Chief Government Statistician in Zanzibar | Government of Zanzibar | Data Producer |
| Accelerated Data Program | PARIS21 | Review of the metadata |
2010-04-28
Metadata version
Version 1.0(March 2010)