DTS in South
Africa
IRDTS 2008
Addis Ababa, Ethiopia
27-30 May 2008
Presented by Joyce Essel-Mensah
Presentation at IRDTS 2008
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Structure of Stats SA
Stats SA
Core production
Economic Stats
Support services
Social Stats
Industry & Trade Stats
Short-term Indicators
Distributive Trade Stats
Industry Stats
Large Sample Surveys
Financial Stats
Price Stats
Employment Stats
Presentation at IRDTS 2008
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Overview – DTS
• Distributive trade statistics in South Africa are published
through sample surveys organized monthly, quarterly,
annually and periodically.
• The surveys are based on samples of private enterprises
operating in the formal non-agricultural business sector of
the economy, excluding financial intermediation, insurance
and government institutions.
• The quarterly and annual surveys are conducted as part on
economy wide surveys.
• There are no DTIs published as yet.
Presentation at IRDTS 2008
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Institutional arrangements
• All Stats SA publications which include the DTS are
conducted in accordance with the Statistics Act 6 of
1999 and subsequent revisions
Presentation at IRDTS 2008
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Main users
National Accounts Division of Stats SA - Require production
and sales statistics of all industries monthly in calculating
quarterly GDP
South African Reserve Bank - requires short term production,
trade and building statistics
Government- Policy makers
Research and/or Educational Institutions - Universities,
Human Sciences Research Council, The Bureau for Economic
Research and the National Research Foundation
Industrial Federations- SAFCEC, SEIFCA, BIFSA
International Organisations - World Bank, International
Statistical Offices and the International Monetary Fund (IMF)
Local and International Media – Reuters, SAFM, Newspapers
Labour unions
Non Governmental Organisations
General Public - Businesses
Presentation at IRDTS 2008
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User needs
• User needs are determined by arranging
advisory committee meetings with internal
and external users
• From 2007, inputs by users are also
obtained via Stats SA’s website
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Surveys
• Monthly:
Wholesale Trade
Retail Trade
Motor Trade
Tourist accommodation,
Food and Beverages
• Quarterly Financial Statistics Survey
(QFS)
• Annual Financial Statistics Survey (AFS)
• Large Sample Surveys (LSS)
Presentation at IRDTS 2008
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Data sources
• Direct collection - depend on respondents
to truthfully and accurately report on the
enterprise
Financial manager or accountant or an
individual with a strong background in
accounting completes the questionnaire
• Administrative sources
Presentation at IRDTS 2008
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Data compilation methods
• Survey frame
• Sampling methodology
• Periodicity (reference period)
Presentation at IRDTS 2008
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Data compilation methods (cont)
Survey frame
• Samples drawn from Business Sampling Frame (BSF) snapshot of Stats SA’s statistical Business Register (BR),
created mainly from the Value Added Tax (VAT) database
supported by Income Tax (IT), UIF, etc
• Units with annual turnover of R300 000 or more in BSF
• Used as a source for updating the BR and in profiling and
delineation
• BR division responsible for creating the BSF and the survey
frames
• Sampling specialists in the Methodology and Standards
division draw samples
Presentation at IRDTS 2008
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Data compilation methods (cont)
Sampling methodology
• Sample comprises of two parts:
•Fully enumeration of all large units
•Samples drawn from smaller units
• Samples are drawn at 4 digit SIC level according to Neyman’s
optimum allocation with special conditions.
• Unit of sampling is the Enterprise. All establishments in selected
enterprises are included in the sample
• Sample sizes range from:
• 850 (Motor trade) to 2 500 (Retail) for monthly
• about 12 000 for whole economy annually
• between 5 000 and 18 000 depending on sector
Presentation at IRDTS 2008
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Data compilation methods (cont)
Periodicity (reference period)
• One calendar month published 7 weeks after reference month
• QFS – Calendar quarters published 3 months after reference
month
• AFS – Financial years of enterprises ending on any date between
1 July of one year and 30 June of the following year
published 14 months after reference month
• LSS – Financial years of enterprises ending on any date between
1 July of one year and 30 June of the following year
•financials published 16 months after reference month
•products published 24 – 30 months after reference month
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Data collection methods
Questionnaires
• Questionnaires are distributed by post, email, fax one period in
advance
• Data collection is through return post, fax, email, telephonically
and visits
• Follow ups are also done through fax, email, telephonically and
visits
Response rates
• A minimum of 80% (normally around 85%) for monthly surveys
with minimum 90% of fully enumerated units (100% for critical
units).
Presentation at IRDTS 2008
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Main data items - Monthly
Wholesale trade survey
• Total wholesale trade sales
• Total income from trade on behalf of and/or on account of others (contract
or fee basis)
Retail trade survey
• Total retail trade sales
Motor trade survey
• Total motor trade sales
• Motor trade sales by type of activity
New motor vehicle sales
Used motor vehicle sales
•
•
•
•
Income from service department or workshop
Direct sales of automotive fuels, oils and additives
Direct sales of spares and accessories
Convenience store income
• Other direct sales and other trading income
Presentation at IRDTS 2008
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Main data items - Others
See attached file and
questionnaires
Presentation at IRDTS 2008
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Data processing and estimation methods
Processing of questionnaires
• Questionnaires for monthly surveys are captured and edited in
one step
• Questionnaires for annual and periodic surveys are edited and
then captured
Estimation methods
• Imputation is done for missing large units and weights adjusted
for small units.
• Overall estimates are derived by adding the two
• Estimates are published at both current and constant prices
(except motor trade) and also seasonally adjusted (except retail
trade)
• Estimates are published for actual values as well as growth rates
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Data dissemination methods
Data is disseminated
• through hard copy publications
• electronic publications through our website
www.statssa.gov.za
• time series in various formats also through our
website and via CDs or email on request
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Problems and difficulties encountered
In conducting the economic surveys
• Obtaining required response rates – anti-government sentiments
results in refusals.
• Locating enterprises as administrative information on the
Business Register is not adequate and reliable for all sampled
enterprises
• Differences in accounting standards and practices by enterprises
can also lead to some inconsistencies in the data used to compile
the estimates. While much of the accounting process is subject to
standards, there remains a great deal of flexibility available to
businesses in the policies and practices they adopt
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Problems and difficulties (cont)
In use of administrative data sources
• Irregular updates of source data
• Errors in source data
In maintenance and improvement of the
statistical business register
• Due to the high volume of units on the register, it is impossible to
pay attention to all units. As such, more attention is paid to large
and complex units at the expense of the smaller units
• Survey areas provide feedback to the Business Register based on
additional information obtained about reporting enterprises but
can sometime be contradictory
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Problems and difficulties (cont)
In use of statistical business register
• Duplication: Duplications of enterprises regarding legal name
and income tax numbers
• Turnover: Instances occur where the same enterprise is
allocated to different size groups in consecutive samples, due to
inconsistencies in the measure of size (turnover)
• Classifications:
Inadequate detail classification lead to inability to publish required
detailed information or provincial breakdowns
Enterprise is allocated different a SIC in consecutive samples
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