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Quality issues on the way from survey to administrative data: the case of SBS statistics of microenterprises in Slovakia. Andrej Vallo, Andrea Bielakova Statistical Office of the Slovak Republic Helsinki, 5 th May 2010. Background.
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Quality issues on the way from survey to administrative data: the case of SBS statistics of microenterprises in Slovakia Andrej Vallo, Andrea Bielakova Statistical Office of the Slovak Republic Helsinki, 5th May 2010
Background Quality in OfficialStatistics2010 • Official statistics in the Slovak Republic based predominantly on surveys • Use of administrative data for production of statistics limited • some in National Accounts and Social Statistics • General trends present in Slovakia • users’ demands vs. budget constraints and respondent burden • re-use of available data expected by respondents • If high quality and low costs are to be achieved, then production system based only on surveys is not sustainable • Adopted strategy: extensive use of administrative data • Starting with the most problematic survey: annual SBS survey of microenterprises
Quality issues in SBS statistics Quality in Official Statistics 2010 Three annual SBS surveys Survey of microenterprises – data not published due to quality issues Low response rate, large proportion of allegedly inactive units, estimates likely to be biased
Outline of a solution Quality in Official Statistics 2010 • Target solution: Use of annual income tax returns data for • replacement of the survey (complete or partial), or • improvement of the estimates • Building on Phare project – complete documentation of available administrative data sources (content, structure, maintenance and accessibility) • First step: a feasibility study • if and how the tax data can be used for SBS • Assessment of the tax data quality - essential precondition of success • Administrative data quality assessment framework was needed
Administrative data quality assessment frameworks Quality in Official Statistics 2010 • Lack of generally adopted AD quality assessment framework • Different approaches: • Development of theoretical background (Wallgren and Wallgren, 2007) • General rules and recommendations (Eurostat 2003, Statistics Finland 2007, UNECE 2008, ESQR 2009, EHQR 2009...) • Individual countries’ quality assessment frameworks (ONS, Statistics Netherlands, Istat...) • Diverse selection of dimensions, diverse understanding of dimensions and various indicators • different degree of correspondence to Code of Practice • different degree of standardisation and formalisation • Input oriented and output oriented indicators
A feasibility study of tax data use for production of statistics Quality in Official Statistics 2010 • Selection and prioritisation of indicators • Input oriented indicators • no experience with production of statistics from the data • Core indicators (necessary conditions): • Coverage and linkability of the data • Availability and comparability of the variables • Additional indicators: • Target population • Definition and identification of survey units • Timeliness and reference period • Structure and format of the data • Metadata and clarity
Coverage and linkability issues Quality in Official Statistics 2010 • Tax returns data come in four separate files • Main Form, Profit & Loss Statements, Balance Sheets, Tax Register • Different identifiers: Unique identifiers of taxpayers different from universally used identifiers of enterprises • the link between them established in the Tax Register • Overcoverage in the Main Forms data • linking with data from Statistical Business Register needed for selection of the units from target population • Undercoverage in the P & L Statements and Balance Sheets • available for 55% of the target population • Incompleteness of the Tax Register (80% of the units) • Errors in links between the identifier systems
Availability of variables (turnover related) Scopeofthevariables Levelof detail in the variables Quality in Official Statistics 2010
Comparability of variables • Comparison of the values of Total turnover provided in the survey and in the tax return (P & L Statement) • Definitions of the variables correspond to each other exactly • The values differ in almost 40% of the comparisons Distribution of non-zero differences less than 10% Quality in Official Statistics 2010
Conclusions and next steps Quality in Official Statistics 2010 • The identified issues do not allow to use the data directly • The Tax register has to be completed and errors in links removed • Further checks have to be applied to ensure internal consistency of the tax data • Models for estimation of missing variables have to be designed afterwards • This will be done in three steps: • Estimation of variables from the P & L statements for the units where these data is missing to ensure complete and correct administrative data • Editing of the data to ensure consistency between tax data and survey data • Estimation of variables for SBS and National Accounts
Thank you for your attention... comments, questions or suggestions are warmly welcome Quality in Official Statistics 2010