the quality of french census
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The Quality of French census. An « old » but good paper…. Written en 2008 by Olivier Lefebvre and Michel Cezard Three parts : A complete presentation of the new french population census method Compliance on the quality criteria of the UN (individual enumeration, universality,….) - PowerPoint PPT PresentationTRANSCRIPT
July 2010
The Quality of French census
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The quality of the French population census July 2010
An « old » but good paper…
› Written en 2008 by Olivier Lefebvre and Michel Cezard› Three parts :
–A complete presentation of the new french population census method
–Compliance on • the quality criteria of the UN (individual enumeration, universality,….)
• the criteria shortlisted by the EuroStat code of best practices (relevance, accuracy,…)
–The management of the census quality
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The quality of the French population census July 2010
II - In line with quality criteria
› The essential characteristics of the census (defined by the UN) :
‐ Individual listing
‐Universality
‐Simultaneity
‐Capacity to supply data on small fields
‐Regularity
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Individual listing
›Data for each individual and each household interviewed in the census
›Organised in a « detail » file allowing for all kinds of comparisons
› Sampling rate sufficient for all kinds of cross-tabulations
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Capacity to supply data on small fields
› Stems from both universality and individual listing›Garanteed by the sampling rate (100% in the small
communes and 40% in the large ones)› The census will supply data on all the communes and
on the « IRIS », districts of about 2000 inhabitants
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The quality of the French population census July 2010
Regularity
›Criteria met by construction because one supplies annual data
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The quality of the French population census July 2010
In line with quality criteria (2)
›Criteria adopted by Eurostat– Relevance– Accuracy and reliability– Timeliness and punctuality– Accessibility and clarity– Comparability– Coherence
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The quality of the French population census July 2010
Accuracy and reliability
› An imprecision linked to the sample survey, but of low amplitude and lower than the one resulting from the «ageing » of data
›Data collection, control and computation methods which considerably reduce the omission bias
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The quality of the French population census July 2010
Timeliness and punctuality
›Recent data –permanently 2 to 3 years for detailed data against 18
months to 10 years in the former system
–results of annual surveys available at the beginning of the following year and integrated to the provisional estimates (at the regional and national level)
› Punctuality : –Legal requirement (legal populations of the communes)
–It guarantees the permanence of the system
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The quality of the French population census July 2010
Accessibility and clarity
› Accessibility guaranteed by resorting to the internet as medium for dissemination
› Systematic feed-back to the communes, with the possibility to re-disseminate this data
›Clarity : important pedagogical and documentation work in the website.
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The quality of the French population census July 2010
III - The management of the census quality
›General principles– control quality step by step–A continuous evaluation approach
› Exemples :–Sampling frames–Data collection–Data processing–Dissemination
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The quality of the French population census July 2010
CENSUS STEPS
Located
buildings register
(R.I.L)
Data Collection Sampling
Data Collection preparation
Households Communities
Communities register Receipt, Checking
Restitution to the mayors Dissemination
Preparation of data entry
Validation
of the data
Estimation of datas :
population and detailed datas
Imputation of missing datas
Coding
Automatic then manual
recovery
Data entry
(external service provider)
Addition of the weights and updating of geography
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General principe 2
› A continuous evaluation approach› Enabled through the annual feature of the operation› After each campaign, decisions of evolutions› Implemented in N+1, but mostly N+2 or N+3
Campaign
Evaluation
Improvements
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The quality of the French population census July 2010
Sep.Juin Jui. Août Oct. Nov. Déc. Mar JuinAvril MaiJan Fév. Sep.Jui. Août Nov. Déc. Jan
Year N-1 Year N
The schedule of a campaign
Sampling
RIL Expertise
Setting-up of organisation
Preparation
Training
Communication
Collection
Reception
Controls
Data processing
Oct.
Dissemination
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The quality of the French population census July 2010
› Any improvement as effects at several points of the process : formulars, formations, protocols, softwares, traitements,…
› Sometimes an improvement has his first impact within 2 or 3 years.
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The quality of the French population census July 2010
The national commission for the evaluation of the census
›Under the rule of the CNIS (National Council for Statistical Information)
› Presided over by a senator› It associates communes, the data users (researchers,
administrations, municipalities), the Insee› It enables an exchange on data collection, control
protocols, useful in improving the processes› It must give an opinion on the texts governing the
organisation of the census
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The quality of the French population census July 2010
The management of quality, process by process : some exemples
› Sampling frames›Data collection›Data processing›Dissemination
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The quality of the French population census July 2010
1 - Sampling frames
› The « quality » survey of the RIL (adress register in large communes)
› An annual survey to assess – The surpluses and the deficits– The surplus-deficit balance– The communes for which the quality is deemed mediocre
› The sample in 2008: 340 000 addresses and 900 000 dwellings› The results
– 1% of dwellings in deficit, 1% in surplus– one commune out of eight beyond 2.5% of deficit– A level of quality higher than that of usual geographical registers – A regular improvement process
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Sampling frames (2)
› The action plans› To improve the quality of the RIL with targetted operations
– Decided and implemented by the Regional Directorates in relation with the communes
– As a function of the strong points and the weak points detected locally
– Training of communes, fieldwork…› Allowing for an operational management of quality because targetted on
specific problems and based on the closeness between the regional teams and the communes
› The future efforts: reduce the surpluses and arrive at level surplus-deficit balance
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The quality of the French population census July 2010
2 - Data collection
› The control procedures during the data collection
› The follow-up and control upon the initiative of the communes
› The controls at the Insee after the data collection (reception-control, in office control, controls in the field)
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The quality of the French population census July 2010
The control procedure during data collection
› A precise data collection protocol
›Checked by the municipal officer
› And by the supervisor
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The quality of the French population census July 2010
Follow-up and control system upon the initiative of the communes
›Upstream from the data collection–Validation of the sample
–Control-validation of the field to be observed carried-out by the enumerator
›Follow-up of the data collection–Follow-up of the progress of work of the enumerator
–Follow-up of key indicators : FLNE(Non response housing forms), vacant dwellings, quality of the log book of the tour-visits
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The quality of the French population census July 2010
The controls at the Insee after data collection
Successive « sorting » › The step of reception-registering of the questionnaires
– Establishment of indicators– Communes with insufficient scores subject to in-depth control
(approx. 15% of the communes representing 30% of the population)
›Desk controls– Verification with the help of the housing Tax files– On the exhaustiveness of the dwellings, the FLNE, the
structure of main/not main residence
› In field controls
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The in-field controls
› They are done by Insee agents› They relate to the communes whose quality is
presumed insufficient›Most often, they confirm the data collection› The errors detected are corrected
N.B. these controls are not representative, therefore their results cannot be extrapolated
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Results of controls of FLNE
› In 85% of the cases, the household enumerator finds the information
› Most often, the FLNE does concern a main residence and the number of persons is correctly estimated
› In 15 % of the cases, FLNEs have been wrongly provided (for non-main residences)
› !!! These figures are not representatives. Controls are made on most difficult cases, where the proba of error is higher
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The quality of the French population census July 2010
3.1 - Data processing : Data entry
›outsourced to indepent service provider
›Quality criteria specifically defined in the specifications– securing of transports and data– maximum rate of error by category of variables
›… and evaluated by an independent control process (sample that has been input twice and arbitration)
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The quality of the French population census July 2010
3.2 – Data procesing : coding of industry and profession
– sample Quality control by twice coding :•Assessing the quality of the automatic coding and manual correction
•Estimating a « threshold » of percentage of bulletins « non codable »
–The contributions of this approach :•adding to the expert system files •the improvement of training and protocols (precisions added in codification rules)
•A finer management of quality, without going in for « excess quality »
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The quality of the French population census July 2010
3.3 - Data processing - Data editing and imputation
–Anayse the share of non responses or incoherent responses
–Imputation of missing data or data presumed non-coherent (hot-deck procedure)
–They are fine-tuned year after year, in view of the quality of the variables produced
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The quality of the French population census July 2010
4 - Dissemination
›A step prepared with the users–Define with them the products and services : two groups
of the CNIS
–Assess their satisfaction : groups of the CNIS and satisfaction surveys
›A systematic validation of the data before dissemination
–At the national level and in each regional directorate since 2009
– Today only at national level.
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