Register-Based Census 2011 in Slovenia – Some

Quality Aspects

Danilo DolencStatistical Office of the Republic of Slovenia

UNECE-Eurostat Expert Group Meeting on Censuses Using Registers, Geneva, 22-23 May 2012

Basic facts (1) Fully register-based census using data from

Administrative registers (5) Statistical register (1) Administrative databases (7) Statistical surveys (full coverage) (6)

Organized as a project Started in 2009 Project team consists of 6 employees

No permanent staff No outsourcing

No budget (savings around 14 mio EUR) Census considered as regular statistical survey

Basic facts (2) Reference date 1 January 2011 Three (four) stages of the statistical process

following the availability of sources concluded by dissemination of data: Basic demographic data (30 April 2011)

Produced quarterly Households and families (30 June 2011) Other population topics (30 December 2011)

Including occupied dwellings – preliminary data Housing (by the end of June 2012)

Delay due to the updated version of administrative data (Real Estate Register)

Background Four basic registers set up by SORS far ago

CPR for the first time used for statistics in 1986 Data already used in 1991 and 2002 Censuses

Register of Spatial Units (address list) in 80‘s Statistical Register on Employment – from 1986

In 2002 data on occupation, industry, place of work taken over Business Register in 1976

Two missing registers available after 2002 Real Estate Register established in 2007 Household Register computerized

CPR supplemented with dwellings number Mini project of SORS and Ministry of Interior in 2010

Preparatory phase (1) Analyses and evaluation

Data sources Quality of data Methodological and processing solutions

Trial census carried out in 2010 - main findings Inconsistencies in Household Register

Easy to improve quality Solved by Ministry of the Interior on the basis of SORS

guidelines Detected errors should be corrected in primary source

Preparatory phase (2) Missing dwelling numbers (DN) in CPR

More than half of population living in multi-dwelling buildings

Two main activities for improvement undertaken Automated determination of DN on the basis of ownership

and residence 49,000 letters sent to residents without DN

– Response rate 75 % including returning letters by post

Still 12.3 % of missing DN in input database

Preparatory phase (3) Unsatisfactory quality of Real Estate Register data

The main problem in whole statistical process SORS analyses sent to register keeper Public data – owners had chance to check and change

data Data on ownership depends on long-lasting legal

matters

Re-updating of final database – selected topics

Linkage of data (1) Identifiers crucial for integration of persons,

households and dwellings PIN (transformed to SID before the process)

Basic identifier for most of linkage regarding persons Household number

Housekeeping concept is implemented Not available for foreigners - 2.1% HN missing Relation to the reference person could be considered as identifier

(key for family generation) Dwelling number

The share of missing data still high – 12.3% Address

Unique identifier of every building

Linkage of data (2) Statistical process almost completely automated

Very complex rules for imputing key identifiers Interface for manual editing incorporated in the

statistical process Better quality – but only 1% records

Household formation of foreigners Family formation

– Multi-member households– Households without data on biological parents or spouses

Quality indicators - identifiers

Identifier Number

of Unchanged Imputed Corrections records Automated Manual Automated Manual

Share in %

Dwelling ID1) 724,479 75.3 11.7 0.6 11.9 0.5

Household ID2) 2,016,423 94.9 2.0 0.1 2.3 0.6

Relation to the 2,016,423 91.6 4.1 0.1 3.3 0.83) reference person2)

1) Multi-dwelling buildings only. 2) Private households only. 3) Manual corrections in the stage of family generation also included.

Current activity status Population aged 15+

Data integration stage

Prio-rity Source content Period Input Output Share %

1 Employed persns 24-31.12. 2010 820.793 804.854 98,12 Registered unemployed persons 1.1.2011 109.994 104.560 95,13 Students enrolment 2010/2011 91.654 77.346 84,44 Scholarship resipients 1.1.2011 31.076 18.353 59,15 Recipients of pensions 1.1.2011 582.594 511.279 87,86 Health insured persons 1.1.2011 1.253.284 187.418 15,07 Recipients of social benefits 2010 94.812 14.455 15,28 Income tax payers 2010 1.619.247 10.124 0,6

Number of records

Imputation Almost all missing data imputed

Except occupation, industry and status in employment for persons working abroad (e. g. daily commuters)

Two main methods used Automated corrections on the basis of existing correlated

data (e.g. activity status by health insurance code) Hot-deck imputation

Imputation rates – lower than in 2002 Census

Activity status 1.5% Occupation (unemployed) 5.2%Occupation (employed) 3.9% Industry (unemployed) 18.0%Industry (employed) 3.7%Place of work 3.8% Educational attainment 1.5%

Where should we be heading ? Integration into social statistics

Census data used for regular surveys (e.g. country ob birth of parents, immigrant background)

Coverage Cooperation with MI to improve over-registration

Geo-referencing Free of charge on the web – application KASPeR

Qualty of processes and outputs Every single change of data from the input databases to

the final census database is recorded Introducing manual interface for improving quality

Common tools – internal integration of IT processes

Over-registration Common problem of register-based systems Missing data on activity status used as indicator

Data from 8 sources used For 1,25 % of population no evidence in any source

Overestimated population groups Foreigners with permanent residence Working age population (30-44 years) – working abroad? Administrative survivors (over 94 years)

Final estimation 0.9% Very comparable with households surveys

No need for post-enumeration survey

Conclusion Two main conditions for input data quality

Close cooperation with register keepers Feedback implemented in primary source

Permanent use of registers Not only for statistical purposes

In future no more ‘‘Census‘‘ but regular annual/periodical survey Every 3-4 years complete ‘‘Census‘‘ Every year education, activity, migration data Twice a year basic demographic data including

citizenship New term instead of ‘‘Census‘‘ ???

Thank you for your attention!