1. Prague EU-SILC Best Practice Workshop, 14th and 15th September 2017
The final estimates on income variables obtained by using only Administrative data in It-silc:
2011 vs 2015
Clodia Delle Fratte and Francesca Lariccia
Prague EU-SILC Best Practice Workshop, 14th and 15th September 2017

2. Outline Introduction Background Aims Data&Methods Results
Concluding remarks

3. Introduction/1
The Italian EU-SILC (It-Silc) survey was launched in and data were collected by means of a multi-sources data collection strategy.
The final It-Silc database is obtained by means of integration at micro level of Survey data and Administrative archives.
The leading idea is to exploit Administrative archives in order to fill in the survey missing values, reduce the measurement errors (correct outliers or unreliable values), improve the under reporting on income components and relative earners.

4. Main steps in the It-Silc production process:
Introduction/2
Main steps in the It-Silc production process:
the estimates of income variables
Raw survey data
Correction of individual structural variables
Correction of household structural variables
Imputation of unit non-response
Correction and imputation of qualitative variables
Integration of Survey data and Administrative archives
Correction and imputation of quantitative variables
Final integrated It-Silc database:
Income variables

5. Integration of Survey and Administrative data
Introduction/3
Integration of Survey and Administrative data
Method to combine micro data from different database
A flow process, starting from the analysis of the phenomenon and data-sources, and finishing with the reconciliation of values reported in the different sources.
Record linkage: the individual ‘matching-key’ is the tax code, i.e. the personal ID number assigned to each person by the Italian tax authority.
Reclassification and reconciliation of income components in the matched dataset:
identification of income recipients, for different types of income;
formulation of hypotheses for the reconciliation of inconsistencies between type of income components and/or income values.

6. As shown in the Workshop in London (data It-silc 2011)
Background/1
As shown in the Workshop in London (data It-silc 2011)
the integrated It-silc database improves the quality of final estimates on income variables, respect to estimates obtained by considering only Survey data
DISADVANTAGES
Timeliness
Coherence
Efficiency
ADVANTAGES
Accuracy
Completeness

7. As shown in the Workshop in London (data It-silc 2011)
Background/2
As shown in the Workshop in London (data It-silc 2011)
for some income components is possible to produce good estimates using exclusively Administrative archives, by replacing the direct interview:
Pensions income
Employee income
ADVANTAGES
Cost and response burden: reduction by eliminating items from the questionnaire when administrative information is available;
Efficiency: process more ‘easy’ due to the elimination of the integration for some administrative income components.

8. As shown in the Workshop in London (data It-silc 2011)
Background/3
As shown in the Workshop in London (data It-silc 2011)
for some income components is possible to produce good estimates using exclusively Administrative archives, by replacing the direct interview:
Pension income
Employee income
DISADVANTAGES
Timeliness: temporal constraint related to the acquisition timing of administrative data;
Coherence: administrative data are collected by conforming the administrative aims and definitions (not statistical).

9. Aims Evaluate the stability of the impact
of Administrative data on final income variables
In particular:
analyse final estimates on income variables obtained by using only Administrative data;
confirm whether for the same income components is possible to produce good estimates using exclusively Administrative archives (by replacing the direct interview).

10. Repeat the same analysis shown
in the London Workshop (data It-silc 2011)
Starting from the final integrated It-Silc database 2015, construction of Administrative database 2015 by using the same process already adopted in 2011;
Comparison of estimates of income variables
(administrative data vs It-Silc):
- levels and recipients of main
individual net income components
(employee income, self-employment income, and pension income)
Estimates using exclusively Administrative sources, by replacing the direct interview
Data&Methods
results 2011 VS results 2015

11. Costruction of Administrative database 2015:
Results
Costruction of Administrative database 2015:
estimates of income variables
Final integrated It-Silc
database
Administrative archives (tax registers, pension registers)
Refusal and not contactable : 17,046 cases
Units with Administrative income data: 28,665 cases
Only It-Silc : 7,428 (matched without tax returns  adm. income 0)
+ 485 (co-resident)+ 239 cases (not matched)

12. Costruction of Administrative database 2015:
Results
Costruction of Administrative database 2015:
estimates of income variables
Units of final integrated it-silc matched
28,665
7,428 matched without tax returns income 0
The ADMINISTRATIVE database
Units of final integrated it-silc not matched
485 (co-resident)+ 239 cases (not matched)
Imputation
of income components on the base of the administrative data:
employee,
self-employment,
and pension

13. Main individual net income components
Results
Main individual net income components
Respect to the exclusive use of Administrative data It-Silc estimates:
Employee income*
number of recipients % %
median income % %
Self-employment income
number of recipients % %
median income % %
Pension income
number of recipients % %
median income % %
* In Administrative data the employee income includes only taxable fringe benefits
2011
2015

14. Results Total household net income = - It-Silc Employee income
Finally, for which income components is possible to produce good estimates using exclusively Administrative archives (by replacing the direct interview)?
Total household net income = - It-Silc Employee income
+ Administrative Employee income
Total household net income = - It-Silc Self-employment income
+ Administrative Self-employment income
Total household net income = - It-Silc Pension income
+ Administrative Pension income 1 2 3

15. + Administrative Employee income
Results
Total household net income = - It-Silc Employee income
+ Administrative Employee income 1
2011
Mean: %
Median: -3.7%
2015
Mean: %
Median: -3.8%

16. Results Total household net income = - It-Silc Self-employment income
+ Administrative Self-employment income 2
2011
Mean: -4.5%
Median: -4.2%
2015
Mean: -3.3%
Median: -2.8%

17. + Administrative Pension income
Results
Total household net income = - It-Silc Pension income
+ Administrative Pension income 3
2011
Mean: +0.6%
Median: -0.1%
2015
Mean: -0.6%
Median: -0.3%
Mean: - 0.6%
Median: -0.3%

18. Comparison between 2011 and 2015 highlights
Concluding remarks/1
Comparison between 2011 and 2015 highlights
Self-employment income NO
Pension income YES
in fact from It-Silc 2016 we eliminate the most
important pensions from the direct interview
Employee income NO
however, we are analyzing ways to simplify
some parts of the questionnaire concerning
employee incomes by exploit administrative
information

19. Employee income  Persistence of income profile
Concluding remarks/1
Employee income  Persistence of income profile
We know that, in Italy, for some kinds of employee (public sector, permanent contract, etc.), the profile does not change over the years.
If in the 1st wave the sample data is confirmed by the administrative data, in the following waves we can eliminate some questions related to employees, as already acquired in the 1st wave.
  Simplification of the questionnaire and
reduction of the response burden.

20. Thank you! & Questions COMMENTS Clodia Delle Fratte dellefra@istat.it
Francesca Lariccia