ESSnet on common tools and harmonised methodology for SDC in the ESS Anco Hundepool, CBS, Luisa Franconi and Daniela Ichim, Istat Sarah Giessing, Destatis Summary ESSnet on Common tools and harmonised methodology for Statistical Disclosure Control in the ESS What is the project about and reasons for it Results achieved in each Work Package (WP) 1
REASONS for an Essnet on SDC harmonisation EU regulations made to harmonise surveys When releasing microdata different MSs have different requirements/strategies: jeopardize utility Allow some flexibility in the choice of SDC methods while maintaining utility AIMS Produce microdata from multiple countries useful for the final users: achieve COMPARABILITY Compare strategies for tabular data protection and include the EU dimension in the process Study sustainability of software at EU level Essnet on SDC harmonisation ESSnet on common tools and harmonised methodology for SDC in the ESS Ended April 2012; Partners: CBS, Istat, Destatis, University of Wien, SCB WP 1: Harmonisation of microdata release at EU level: case study (Istat) WP 2: Case studies on tabular data (Destatis) WP 3: Future directions of SDC software tools (Statistics Netherlands) 2
WP1- Microdata dissemination framework Original microdata risk assessment Apply SDC methods to reduce risk while maintaining some utility comparability Evaluate utility define benchmarking statistics Original microdata Disclosure risk Utility SDC methods Anonimized microdata WP1- Microdata dissemination framework The actors and their objectives Introduce bounded utility into SDC paradigm by means of benchmarking statistics Case study: Structure of Earning Survey 1. Data producers a) Maintain what is already published by MS and EU b) Be coherent : relationship amongst variables c) Avoid identification SDC paradigm 2. Data Users/researchers a) care of how data is used in scientific research Gender pay gap, Linear models Different methods can be used by MS BUT maintain the benchmarking statistics 3
WP1- Microdata dissemination framework WP 1: Case Study: Structure of Earning Survey Release of microdata in multiple countries Task 1-1: Choice of benchmarking statistics: MS constraints Meeting at LAMAS WG Task 1-2: User needs: definition of benchmerking statistics Task 1-3: Definition of methodologies We have modified already proposed anonymisation methods for past SES microdata in order to satisfy the chosen benchmarking statistics Task 1-4: Implementation and reporting: different methods implemented routines are available on the web site together with documentation Task 1-5: Final report Application of different methods to microdata from partners in the project and analysis of the results obtained. Satisfying results were obtained. Report on governance structure and workflows of the process (through GSBPM) WP1- Microdata dissemination framework Governance structure : organisation of the implementation process In order to study viability of the proposed framework we address issue related to: Architecture of the framework: SDC for microdata mapped to the GSBPM (flows of data and metadata) We provide an analysis of different options for the organisational architecture We suggest actors in the ESS and their role the SDC decision process More info available on the project web site: http://neon.vb.cbs.nl/casc/..%5ccasc%5cessnet2index.htm 4
WP2: Case Studies on Tabular Data Suggest methodological framework for harmonization of SDC methods for business data based on cell suppression Study alternatives of perturbation based SDC Give recommendation for future work Census 2011: first evaluation of individual countries WP2 Results Cell suppression: Case Studies Development of a generic table model for secondary disclosure risks to enhance practical implementation of cell suppression methodology Test report on application of the generic table model for SBS and FATS tables under the respective table release concepts of Destatis, Istat, CBS and SCB Conclusion: Applicable linked table solutions to SBS and FATS Generic table model useful for communication between data managers and SDC experts Long term vision: Specialized tools to collect table model information as standard meta-data along the production process 5
WP2 Results Cell suppression: Software Issues of the Case Studies At the MS level: All instances of the case studies can be handled by the now available linked-tables approach of t-argus SAS wrapper packages for t-argus available now at SCB and Destatis At the EU level Explore the complexity of the special EU-MS level table model Extension of t-argus to support application of the hypercube method in the context of this table model (No need for the CIF interface to the hypercube method anymore!!!) Conclusions for future work: Implement special facilities available in the Destatis SAS wrapper package to handle complex table models (in particular the EU-MS table model) WP2 Results Study and demonstrate stochastic perturbation methods Main complexity of tabular SDC: Generating the table model for secondary disclosure risk Integration with one task of DwB project Develop methodology based on stochastic noise to protect tabular data on the fly without need to set up table models Method must be integrated into standard tabulation packages Conclusion: Ideal for harmonizing SDC between EU and MS if adopted by all MS, and if IT solutions available Useable for SDC of EU level tables only? (e.g. if MS stick to cell suppression) Not clear. More research needed Implementation in t-argus recommended 6
WP2 Results Census SDC Workshop in April 2012 Need for knowledge of the SDC of Census Data No consensus yet, so: Workshop has been organised to learn from each other 7 invited papers, 4 shorter papers and a panel discussion Report/conclusions available Several conclusions presented by Eurostat at the Census Working Group Meeting WP3 - Future directions of SDC software tools AIM: sustainability of the toolset Results: Extensive description of the current µ-argus and τ-argus Description of sdctables A blueprint of the new µ-argus and τ-argus in Open Source Analysis of Open Solvers Description of the SAS interface tool 7
WP3 - Future directions of SDC software tools A project is planned to rewrite τ-argus as described in WP3. Open Source Platform Independent Also Open solvers OS Cell-suppression is being developed in Data without Boundaries project. OS rounder is an open issue, but current version still available. Dissemination 2 papers and a poster at NTTS2011 presentations at the LAMAS WG and SDC Expert group 3 papers at UNECE-Eurostat worksession 1 paper at PSD2012 Palermo More: http://neon.vb.cbs.nl/casc/ 8
Thank you! 9