Eurostat Overview of the project Meeting of the Expert Group on the integration of the European social surveys January 2015

Eurostat Purpose of the meeting To review/discuss the work and the developments carried by Eurostat for the integration and streamlining of social surveys To identify needs for future development To give an overview of the methodological work currently being carried out To explore developments made at country level in the field of survey integration

Eurostat Eurostat VIP project "Streamlining and integration of the European social survey" (2011) The project aims to assess scenarios for an integrated approach to household/individual micro-data collections for social statistics in order to rationalise the current system of stand-alone social surveys The project should cover technical and methodological work to underpin concrete proposals to be piloted before a decision is taken To create the basis for a future integrated system of social surveys by reaping the methodological and technological possibilities that have emerged in the recent years To accommodate resources constraints in the Member States through an innovative approach towards prioritisation and by setting the conditions to achieve further efficiency gains in the statistical production 3

Eurostat Background information DSS meeting of September 2014: Eurostat presented the state of play of the VIP project on streamlining and integration of social surveys The DSS appreciated the methodological work done internally in Eurostat as this could be beneficial both at ESS and at national level. It expressed its broad agreement with the direction of the project and welcomed the re-launch of the Expert Group on the Integration of the European Social Surveys. The Expert Group should review the work and the developments carried out at Eurostat level (and by Member States) in order to pave the way for future decision making on the second step of the modernisation 4

Eurostat Reference system architecture Modular statistical system The variables have been split into mutually exclusive groups of variables, called modules. The modules will be distributed into instruments each instrument consists of a fixed set of modules each module may be present in many instruments. Data collection for each instrument may take place independently of the other instruments or with different degrees of coordination between them. The estimation of target parameters will pool the required input data from all instruments with which they have been collected. Expected benefits: Reduced response burden Increased precision Increased analytical potential of the data Quick and efficient response to emerging needs

Eurostat Design 6 Core modules: included in all data collections Harmonised modules: used in the surveys of different statistical domains. Specific modules are used in only one survey Modules: basic building blocks (groups of variables to be kept together for analytical/data collection reasons) GENDER BIRTHDATE BIRTHPLACE CITIZENSHIP DEMO (…) Core modules Harmonised modules HATLEVEL HATVOC EDUCATT HEALTHSTAT HEALTHPROB DISAB HEALTH (…) Specific modules HATYEAR HATMONTH HATFIELD EDUCCHAR ACCNUMB ACCDATE ACCTYPE ACCIDENT (…)

Eurostat Design 7 Instruments: Fixed set of modules for which data is going to be obtained for the same individuals A module can be present in more than one instrument Instruments allow the observation of joint distributions DEMOEDUCATTEDUCCHAR DEMOEDUCATTHEALTH DEMOHEALTHACCIDENT

Eurostat Data compilation For each instrument one sample is selected Data are then compiled for each individual for each module of the corresponding instrument The compilation can be done via a tailor made survey or via the re-use of existing data (administrative records) 8 DEMOEDUCATTEDUCCHAR n1n1 DEMOHEALTHACCIDENT n2n2 DEMOEDUCATTHEALTH n3n3

Eurostat Estimation The estimation of target parameters will be based on pooling of the required input data from all instruments with which they have been compiled 9 EDUCCHAR ACCIDENT DEMO EDUCATT HEALTH

Eurostat Methodological work (2011 on ) Methodological helpdesk requests: Input information needed for pooling data from two surveys, for three health variables (including the source code in R) ; Distribution of modules in longitudinal instruments: (including the source code in R) to implement methods for three surveys; Possibility to accommodate a modular approach within the current regulatory framework for European Social Survey Methodological contract for the "Development of methods and scenarios for an integrated system of European Social Surveys" (main methodological developments and deliverables D1, D2..D4..D12..) Methodological contract on "Integrated system of European Social Surveys: generalisation of the existing framework to cover longitudinal and other complex aspects

Eurostat The toolbox developed D1 – Methods for pooling data D2 – Methods for determining the sample size of each instrument D4 – Methods for arranging modules into instruments

Eurostat D1 - Methods for pooling data Estimation methods to be applied in the context of the “Integration of European Social Surveys Analyses of alternative sampling scenarios (master sample and subsamples) which affect the construction of estimators and the calculation of precision estimates with respect to negative coordination, independent-subsample and positive coordination Methods for the estimations when information on some variables is available in a number of different sub-samples which might be combined to yield higher level precision estimates Methods for aligning common variables across subsamples in such a way that the estimation of non-common variables will benefit as well

Eurostat D1 - Methods for pooling data

Eurostat D2 - Sample size determination procedures How to determine the sample sizes of the sub-samples that are associated to instruments so that the precision requirements for all the modules are met simultaneously? Optimal allocation of sample size of instruments can be obtained by minimising the cost while respecting the constraints by applying the simplex algorithm

Eurostat D2 – sample size determination

Eurostat D4 - Instrument composition methods Guidelines on how to determine the optimal composition of the instruments in terms of modules under the conditions that: crossing criteria and the frequencies of modules are respected, the instruments are manageable in number, the instruments have reasonable questionnaire size the instruments composition is appropriate The simplex algorithm is easily applied if the set of instruments is predefined What is the best way to compose instruments? Based on a pre-specified number of instruments, “admissibility criteria” and precision requirements, the simulated annealing algorithm starts from a given scenario (any “admissible” instruments composition) and randomly looks for alternative “admissible compositions”, calculating their costs

Eurostat D4 – instrument composition

Eurostat Other results Representation of the current set of instruments in European social surveys Frame alignment Testing the methodological developments Guidelines for managing constrains Provisional roadmap

Eurostat Open questions Is the envisaged system appropriately reflecting the spirit of the Wiesbaden memorandum? What are the needs for future developments? Is the roadmap properly covering all the methodological and operational challenges related to the moving from a survey stovepipes system to an integrated architecture for social micro-data collections (including surveys and other data sources)? How to involve Member States?