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which official statistics are compiled and disseminated through
website.
https://www.nbs.go.tz/publications/acts-and-regulations
1.2.2 Internal governmental access to statistics prior to their release is publicly identified.
• The public is made aware of internal government access to statistics prior to their release to the public.
To maintain professional independence, the PPI is not released to any Government organization or agency prior to dissemination. There is no internal government access to PPI outside NBS before public release.
1.2.3 Products of statistical agencies/units are clearly identified as such.
• Statistical products are clearly identified so that the public is aware of what the data producing agency takes responsibility for.
PPI publications are clearly stated by name and logo of NBS to ensure clarity of the products that are produced by the institutions. Currently, there is no joint PPI publication and attribute request.
Through clear identifications of statistical products and ensuring transparency in how data is collected and managed, the Bureau helps to ensure accountability, builds public trust, and provides a reliable foundation for informed decisions.
1.2.4 Advance notice is given of major changes in methodology, source data, and statistical techniques.
• Users of statistics are made aware in advance of major changes in methodology, source data, and statistical techniques.
NBS gives advance notice of any major changes in methodologies, data sources and statistical techniques used to prepare PPI to the data users. Public and key stakeholders are informed prior to any change through public notice, workshops, meetings in order to comment on the proposed new base methodology.
1.3 Ethical standards
1.3.1 Guidelines for staff behaviour are in place and are well known to the staff.
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• A clear set of ethical standards has been prepared.
The NBS has developed a comprehensive set of ethical standards such as staff regulation, code of ethics and conducts which are designed to guide management and staff. These set of ethical standards are documented and publicly available, ensuring transparency.
• Staff are made aware of the ethical standards.
NBS staff are made aware of ethical standard principles and guidelines set by the organization under the Code of Ethics and Conducts for Public Servant. The guiding rules and ethical standard provided and they are periodically reminded during the staff meetings to maintain the standard of office. However, during the recruiting the new staff, induction course is provided in order to understand public servant ethics.
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- Methodological soundness
2.1 Concepts and definitions
2.1.1 The overall structure in terms of concepts and definitions follows internationally accepted standards, guidelines, or good practices.
• Concepts and definitions used to compile the PPI are in broad conformity with guidelines outlined in the 2008 SNA and the PPI Manual.
PPI is produced according to international standards recommended by the IMF PPI Manual. The NBS adheres to the concepts and definitions outlined in the manual and has developed its own concepts and definitions for official statistics, which align with the 2008 SNA. All documents serve as the methodological reference for producing PPI.
• Output estimates are compiled at a sufficient level of industrial and commodity detail.
The Producer Price Index (PPI) release is compiled using the International Standard Industry Classification (ISIC) Revision 4, which categorizes economic activities globally. The PPI is aggregated at the one-digit section and two-digit division levels of the ISIC classification to maintain confidentiality and protect sensitive data.
2.2 Scope
2.2.1 The scope is broadly consistent with internationally accepted standards, guidelines or good practices.
• The scope of the PPI is the maximum feasible fraction of the total output of resident establishments/enterprises.
The PPI covers domestic establishment as indicated in IRIS 2008, UNIDO Industrial Statistics guidelines and methodology and ISIC Rev 4, which include mining and quarrying, manufacturing, electricity, gas, steam and air conditioning supply, and water supply; sewerage, waste management, and remediation activities. It covers a total of 203 establishments and 68 activities of ISIC Rev. 4.
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• The delimitation of the constituent units of the economy is in accordance with the 2008 SNA.
The NBS has adopted the principle that the scope of the PPI should encompass all domestic production of goods and services.
• Differences in the scope of coverage between the PPI and the 2008 SNA should be made public and known to users.
The inclusion or exclusion of products is aligned with international standards, and illegal market goods are excluded.
2.3 Classification/sectorization
2.3.1 Classification/sectorization systems used are broadly consistent with internationally accepted standards, guidelines, or good practices.
• The classification and sectorization used in the compilation of PPI are in broad conformity with internationally recommended systems.
To improve the comparability and reliability of economic statistics, a different classification system, in line with international recommendations, is used in compiling producer price statistics. The 2004 PPI Manual serves as the guide. However, the Industry and Construction Statistics Department utilizes the ISIC Rev. 4, to classify the economic activities of establishments.
2.4 Other quality management
2.4.1 Market prices are used to value flows and stocks. • The valuation rules used for recording flows and stocks are in accordance with the 2008 SNA.
The PPI weight is based on gross output derived from the Annual Survey of Industrial Production 2015, with a valuation at basic prices, which excludes taxes and transport costs. Transfer prices are included in the PPI compilation. The PPI does not use intermediate consumption to calculate weights.
2.4.2 Recording is done on an accrual basis.
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• The timing rules used for recording flows are in accordance with the 2008 SNA.
During data collection, output is recorded from sales of industrial and non-industrial services at basic prices, as well as the value of inventories of finished goods and work-in-progress are recoded in the period they are produced.
2.4.3 Grossing/netting procedures are broadly consistent with internationally accepted standards, guidelines, or good practices.
• The grossing/netting procedures are in accordance with the 2008 SNA.
The grossing and netting procedures are compiled in accordance with the SNA 2008 and UNIDO Industrial Statistics guidelines and methodologies. Transactions of goods and services between establishments belonging to the same enterprise are valued at basic prices due to the fact that the statistical unit for the PPI is an establishment and not enterprise.
- Accuracy and Reliability
3.1 Source data
3.1.1 Source data are obtained from comprehensive data collection programs that take into account country-specific conditions.
• The data collection programs employed to compile the producer price statistics are adequate.
The establishment list is developed during the rebasing exercise, with data collection conducted at the regional level. PPI weights are derived from the gross output in each ISIC Rev 4 group. A sample of establishments to be included is selected using a cutoff sampling procedure.
Sometimes, data are received from MDAs (e.g., the Ministry of Water, and TANESCO) to validate data collected from other authorities.
• Annual statistics are collected through a regular enterprise establishment survey program for compiling PPI output weights, intermediate input weights (input price index), and
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product weights.
The Statistical Business Register is used as the sampling frame for establishment-based surveys and is maintained through continuous updates of establishments. Maintenance is an ongoing process in which statistical units are regularly updated using administrative data.
The Annual Survey of Industrial Production (ASIP) is conducted after every two years. Administered questionnaires account for all variables needed for Producer Price Statistics. The current PPI uses weights from the ASIP 2015. However, not all annual surveys are conducted as planned due to financial constraints.
In the absence of a business register, a listing exercise is conducted using data from the Census of Industrial Production and lists of establishments obtained from administrative sources, such as the Ministry of Industry and Trade, Confederation of Tanzanian Industries, etc.
The PPI sample design ensures the establishments are represented properly which encompasses four sub-sectors of industry from ISIC Rev 4: Mining and Quarrying; Manufacturing; Utilities (Electricity, Gas, Steam, and Air Conditioning Supply); and Water Supply, Sewerage, Waste Management, and Remediation Activities.
The PPI questionnaire is designed following all necessary processes, including pre-testing and piloting, with any observed changes taken into account.
The value added of each sampled establishment is collected and then aggregated to the one-digit level across all four industrial subsectors.
• Monthly or quarterly price statistics are collected through a regular establishment/enterprise survey program to compile the PPI by activities and by products. The PPI covers industrial activities as outlined in the IRIS 2008 and UNIDO Industrial Statistics guidelines and methodology. Establishments engaged in the four industrial subsectors were
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selected from the Annual Survey of Industrial Production (ASIP) of 2015.
The value added of each sampled establishment is collected and then aggregated to the one-digit level across all four industrial subsectors. A cutoff sampling procedure was used for the Producer Price Survey.
The selected sample is regularly updated using administrative data from industrial stakeholders. The prices collected are entered into Excel at the four-digit level, then aggregated to the three-digit level and, finally, to the two-digit level.
• The survey is of matched model pricing. The PPI questionnaire includes the name of the commodity, unit of measure, and the price of the respective commodity, with data collected each quarter for easier comparison from quarter to quarter and year to year.
• Periodic (two or more years) surveys/censuses of output and intermediate consumption are conducted on a regular basis.
The PPI relies on the Census of Industrial Production, the Annual Survey of Industrial Production, and the Statistical Business Register, although they are not updated annually due to financial constraints.
The coverage of the Census of Industrial Production includes both small establishments (1-9 employees) and large establishments (10 or more employees), taking into account the four categories involved in industrial statistics as recommended in IRIS 2008 and PPI manual 2004. It covers four industrial activities as defined in ISIC Rev. 4.
• The data collection programs are sufficiently open and allow for versatility to new developments in sources.
The improvement of the basket of goods and services is achieved during the rebasing activity. During rebasing, new commodities and prices are collected for the development of the PPI. Before releasing the new PPI series, the NBS and key stakeholders meet to discuss updated information on producer price movements, industrial
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activities involved, and the products covered. Press and research paper are not monitored. In the compilation of the Producer Price Index, international guidelines such as the PPI Manual and UNIDO guidelines are adhered to, including any necessary changes that need to be taken into account.
3.1.2 Source data reasonably approximate the definitions, scope, sectorization, classifications, valuation, and time of recording required.
• Source data approximate the definitions, scope, classifications, valuation, and time of recording required in the PPI.
The definitions, scope, and classifications of data sources for PPI statistics align with IRIS 2008, the PPI Manual 2004, Industrial Statistics Guidelines and Methodology 2010 (UNIDO, 2010), and ISIC Rev. 4.
The price survey collects prices of selected commodities on a quarterly basis from sampled establishments, adhering to statistical procedures.
3.1.3 Source data are timely.
• The data collection programs provide for the timely receipt of data.
Data collection is completed within a month after the end of the quarter, and the PPI is disseminated within two months after the data collection month.
During the initiation survey, NBS and owners of establishments agree on the submission due date for the questionnaire each quarter, which is then noted on the data collection form.
Follow-up mechanisms are in place, where compilers either make phone calls or visit the establishments though sometimes there is delay of data submission from establishments.
3.2 Assessment of source data
3.2.1 Source data including censuses, sample surveys, and administrative records are routinely assessed, e.g., for coverage, sample error, response error, and non-sampling error; the results of the assessments are monitored and made available to guide statistical processes.