Strategies to achieve SDC harmonisation at European level: multiple countries, multiple files, multiple surveys Daniela Ichim and Luisa Franconi Istat, Unit on Methods for statistical data confidentiality

Outline Motivation The problem: how many releases? Dissemination strategies Multiple countries: comparability Multiple releases and multiple surveys Conclusions

Dissemination process at transnational level: constraints Multiple actors Heterogeneity Laws and Standards: Organisation of the Statistical System Access to original confidential microdata Microdata transmission Microdata dissemination

Multiple … Multiple countries Multiple countries Multiple countries Multiple surveys Multiple countries Multiple countries Multiple countries Multiple countries SURVEY1 TABLES1 PUF1 MFR1 OTHER1 Multiple releases MS1 Multiple releases SURVEY2 TABLES2 PUF2 MFR2 OTHER2 SURVEYX TABLESX PUFX MFRX OTHERX Multiple releases Multiple releases SURVEY1 TABLES1 PUF1 MFR1 OTHER1 Multiple releases MS2 SURVEY2 TABLES2 PUF2 MFR2 OTHER2 SURVEYX TABLESX PUFX MFRX OTHERX Multiple releases SURVEY1 TABLES1 PUF1 MFR1 OTHER1 Multiple releases Multiple releases MS27 SURVEY2 TABLES2 PUF2 MFR2 OTHER2 SURVEYX TABLESX PUFX MFRX OTHERX Multiple releases

Multiple countries:Dissemination Original microdata Utility Anonymized microdata SDL methods Disclosure risk

Dissemination strategies: level 1 Microdata  apply a SDL method Evaluate risk and utility Disclosure risk SDL methods Original microdata Anonymized microdata Single release Utility R U

Dissemination strategies: level 2 Microdata  risk assessment Apply SDL to reduce risk Evaluate utility Anonymized microdata Disclosure risk Utility SDL methods Original microdata Single release R U

Dissemination strategies: level 3 Microdata  risk assessment Apply SDL to reduce risk maintaining some utility Evaluate utility SDL methods Disclosure risk Original microdata Utility Anonimized microdata Single release R U

Dissemination strategies: degrees of freedom List of candidate methods Suitable to the scenario Protect w.r.t. the scenario Easy to use, etc Flexible methods Parameterisation Stratification Bounded utility Tools: open source

Multiple countries – data utility Users need to make comparisons between different countries. HOW to guarantee it? Utility Comparability Multiple countries Comparability Bounded utility

Comparability Comparability aims at measuring the impact of differences in applied statistical concept and procedures when statistics are compared between geographical areas, non-geographical domains or over time. It is the extent to which differences between statistics are attributed to differences between the true values of the statistical characteristics

Comparability: procedures HOW to achieve it? 1 Set benchmarking statistics and assess the effects of different practices on this set of predefined statistics 2 Define thresholds to define when action is needed 3 Agree on a process for choosing acceptable practices Multiple countries

Benchmarking Non-statistical criteria Statistical indicators Thresholds Actions to be performed when the condition is not met Ichim, D., Franconi, L. (2010), ‘Strategies to Achieve SDC Harmonisation at European Level: Multiple Countries, Multiple Files, Multiple Surveys’, J. Domingo-Ferrer and E. Magkos (Eds.): PSD 2010, LNCS 6344, pp. 284–296, 2010. Springer-Verlag Berlin Heidelberg. Multiple countries

Essnet on SDC Harmonisation Proof of concept for the proposed framework Microdata A survey will be chosen Analysis of users’ requirements Benchmarking statistics will be agreed Various methods will be tested Tables Similar approach will be applied to tables (SBS and Inward FATS)

Different dissemination products Microdata, tables, … Conclusions Different dissemination products Microdata, tables, … Harmonisation as a mean of Standardisation Tight collaboration between actors ESSnet during 2011 to make a proof of concept of the proposed framework