1. An assessment of the robustness of weights in the Famille et Employeurs survey Nicolas Razafindratsima (razafind@ined.fr)razafind@ined.fr & Elisabeth Morand (Elisabeth.Morand@ined.fr)Elisabeth.Morand@ined.fr INED European Conference on Quality in Official Statistics, Rome, July 2008

2. Outline Introduction The Famille et Employeurs survey Methodology of weights calculations Results Conclusion

3. Introduction In indirect sampling : the generalized weight share method (Lavallée, 2002 & 2007) is a simple and easy strategy to produce unbiased estimations Objective of this study : to expose the implementation of this method for the Familles et Employeurs survey (Ined/Insee, 2004-2005) : difficulties, and robustness of the weights obtained.

4. The Familles et Employeurs survey Main purpose : to study professional and family life conciliation: - from the employees point of view - from the employers point of view Can behaviours within the family be explained through employers rules and characteristics? A matched survey: employee  employers

5. The household survey Sampling strategy : - a sample of 11 719 dwellings drawn from the INSEE master sample  6 167 of them answered - interview of 1 or 2 individuals, aged 20-49, in each household (random sampling if >2)  9 547 respondents Face to face interview. Questionnaire on demographic events (birth, unions), family life organization, etc., in relation to individuals professional context

6. The establishment survey Target : Establishments of 20 employees or more Individuals respondents were asked to give their employers name, address, national identification number as well as their size and sector. A self administered questionnaire was sent to the establishments. Possibility to answer by paper or by the Internet. 2 673 respondents.

7. Weighting methodology The basic for establishments weighting methodology : the generalized weight share method Where : Wi=weight of establishment i Wj=weight of individual j (those in the sample) Li= number of eligible employees (aged 20-49) in the establishment i

8. Weighting methodology Difficulties : - the choice of individuals weight (non-response, calibration) - the estimation of the number of employees aged 20-49 in the establishment [- establishment non-responses]

9. Weighting the sample of individuals Non response variations : – At the household level (non-response higher in urban areas, for collective dwellings, etc.) – At the individual level (non-response higher for males, single persons, less-educated people, etc.) Non-response adjustments : – At the household level : using corrective response rates within response homogeneity groups – At the individual level : calibration (on Labor force survey data) - on a single variable : gender*age - or on 7 variables : gender*age, employment status, nationality, region, highest diploma, urbanization status, household size

10. Distribution of individuals weights Calibration variablesNMeanCV (%)MinMedianMaxMax/ Min Gender*age9 5472 538,148,0557,52 10114 754 26,5 7 variables9 5472 538,151,9440,12 16014 435 32,8

11. Estimation of the number of eligible employees (aged 20-49) Number of employees (total and by age groups) asked in the establishment questionnaire But number of 20-49 not available for 16% of the establishments (item non-response) Imputation of number of 20-49 when non-response : using coefficients of a regression model among respondents, linking nb of 20-49 to total (one model by activity sector) For 2/3 of the establishments, total size is also available through the SIRENE directory. Allows an other estimation of 20-49 number for evaluation purposes

12. Distribution of total size NMeanCV (%)MinMedianMaxMax/ Min Declared2 673540,5264,620,0152,044 7952 239,8 SIRENE (after imputation) 2 673575,6285,020,0151,036 0341 801,7

13. Distribution of number of 20-49 Nb of missi ng MeanCV (%)MinMedianMaxMax/ Min Declared433419,5259,03,0110,030 57910 193,0 Imputed using declared 0398,0256,53,0109,030 57910 193,0 Imputed using SIRENE 0430,7286,513,9113,228 4472 049,0

14. Summary of the options for establishments weighting Calibration variables for individual weights Estimation of the number of employees aged 20-49 Imputation using declared size Imputation using SIRENE size Gender*age onlyP1P2 7 variables- P3 - P3tr : trimmed P5 & P95 then adjusted on the total P4 Employees weight=establishment weight*nb of employees

15. Distribution of establishment weights MeanCV (%)MinMaxMax/ Min Nb of weights < 1 P141,8138,60,3646,02 583,951 P241,1128,70,1476,47 217,455 P341,3140,80,2592,03 235,060 P440,7134,00,1459,98 516,367 P3tr 41,3 106 1,7155,291,20

16. Distribution of employees weight MeanCV (%)MinMaxMax/ Min P14 019,681,6819,969 793,985,1 P23 835,362,1819,935 304,643,1 P33 926,081,4586,966 394,2113,1 P43 751,266,0586,937 502,263,9 P3tr4 409,082,1980,4176 226,7 77,7

17. Percentage of establishments having a crèche

18. Percentage of employees working in an establishment with a crèche

19. Conclusion Weight sharing method : – A simple and easy to implement method – However, difficult to implement in the Famille et Employeurs survey, due to : non-responses on the ‘link’ variable High dispersion of the size variable More sensitive to the link variable than on specification of the individual weights All the computed weights present great variability Weight trimming may improve precision at the establishment level, but fails to do so at the employees level

20. References Lavallée, P. (2002) : Le sondage indirect, ou la méthode généralise du partage des poids, Bruxelles, Presses de l’université libre de Bruxelles et Paris, Ellipses, 242 pages. Lavallée, P. (2007) : Indirect sampling, New York, Springer (Springer series in statistics), 245 pages.

21. Thank you for your attention !