1 The Process of Practicing Statistical Disclosure Control in Tabular Data at Statistics Sweden Q2010 Helsinki, May 4-6 Ingegerd Jansson, Michael Carlson, Fredrik Bernström

Recent work at Statistics Sweden SDC in tables – a common process Handbook on statistical disclosure control for tabular data Software Training Future work

SDC in tables - a common process Damage assessment 3. Protect table Table re- design ”Publish” 4. Utility assessment Protection required? 1. Disclosure risk assessment Table speci- fication Yes No Yes No 2. Damage risk assessment Acceptable?

Handbook on SDC for tabular data The Handbook describes - the common process - preliminaries and some theory - a structure to guide in decision-making The Handbook does not describe - theory in detail (links to ESSNet handbook and other relevant sources) - software in detail

Handbook on SDC for tabular data - a structure to guide in decision-making Four entrances: Type of table: frequency, magnitude Type of data: total enumeration, sample survey Frequency tables: –Key variables –Key and target variables Magnitude tables: –Non-negative magnitudes –Negative magnitudes Other aspects where appropriate: type of target object, variable properties, non-response, linked tables, etc

Handbook on SDC for tabular data - a structure to guide in decision-making For each category of tables, the goal is to describe: –Risk scenario –Appropriate methods and parameter values for assessment of risk in table –Appropriate methods and parameter values for protection of table –Implementation and computer aid –Example

So far: τ-Argus, SuperCross and SAS Project on how to use and incorporate τ-Argus: –evaluate the functionality of τ-Argus with respect to the requirements at Statistics Sweden, i.e. different types of tables and situations (given by the structure of the handbook) –evaluate how to incorporate τ-Argus with the present and planned production system at Statistics Sweden –The goal is that τ-Argus (or any other software) should work smoothly within the production process. This pertains both to technical solutions and to the work process. Software

8 Software -  -ARGUS and SAS T-Argus PC.....NET SuperCross SAS Command Metadata Data HTML-report Outputfile(s) (CSV) Logfile

Statistical methodologist: –two-day introductory course that will be followed up by other types of training –should be able to assist in design, testing and production where necessary Survey managers/statisticians: –general overview of statistical disclosure control and in particular of the proposed process for SDC Training

To ensure that protection is actually being carried out where necessary, and that it is being done in a manner that follows best practices Standardized production → no need to invent the wheel over and over again Standardized tools → simplified implementation and maintenance ISO standard on market, opinion, and social research Why are we doing this?

Further development of technical support Model for continued management The 2011 Census Micro data Future work