6. Accuracy and reliability |
Top |
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6.1. Accuracy - overall |
[not requested for the LFS quality report] |
6.2. Sampling error |
Publication thresholds |
Annual estimates |
Annual estimates - wave approach |
(if different from full sample thresholds) |
Limit below which figures cannot be published |
Limit below which figures must be published with warning |
Limit below which figures cannot be published |
Limit below which figures must be published with warning |
4653 |
7755 |
NA |
NA |
|
6.2.1. Sampling error - indicators |
Coefficient of variation (CV) Annual estimates Sampling error - indicators - Coefficient of variation (CV), Standard Error (SE) and Confidence Interval (CI) |
|
Number of employed persons |
Employment rate as a percentage of the population |
Number of part-time employed persons |
Number of unemployed persons |
Unemployment rate as a percentage of labour force |
Youth unemployment rate as a percentage of labour force |
Average actual hours of work per week(*) |
|
Age group: 20 - 64 |
Age group: 20 - 64 |
Age group: 20 - 64 |
Age group: 15 -74 |
Age group: 15 -74 |
Age group: 15 -24 |
Age group: 20 - 64 |
CV |
0.30 |
0.3 |
1.1 |
2.1 |
2.1 |
3.1 |
0.2 |
SE |
6538.2 |
0.2 |
4058.0 |
2853.4 |
0.1 |
0.5 |
0.07 |
CI(**) |
(2136756.4 2162286.2) |
(72.9 73.8) |
(354192 370099.3) |
(131081.4 142266.8) |
(5.4 5.9) |
(14.3 16.2) |
(36.3 36.6) |
Description of the assumption underlying the denominator for the calculation of the CV for the employment rate |
The CV for the number of employed persons (aged 20-64) and the employment rate (aged 20-64) are identical because the denominator of the employment rate (aged 20-64) is the total population (aged 20-64) which has a zero CV and the total population by age group are margins used in the calibration process. |
Reference on software used: |
Reference on method of estimation: |
SAS - creation of replicates using custom designed software which are then used to generate the variance measures required. |
NR |
Coefficient of variation (CV) Annual estimates at NUTS-2 Level |
NUTS-2 |
CV of regional (NUTS-2) annual aggregates (in %) |
Regional Code |
Region |
Number of employed persons |
Employment rate as a percentage of the population |
Number of part-time employed persons |
Number of unemployed persons |
Unemployment rate as a percentage of labour force |
Youth unemployment rate as a percentage of labour force |
Average actual hours of work per week(*) |
|
|
Age group: 20 - 64 |
Age group: 20 - 64 |
Age group: 20 - 64 |
Age group: 15 -74 |
Age group: 15 -74 |
Age group: 15 -24 |
Age group: 20 - 64 |
IE01 |
Northern and Western |
0.79 |
0.79 |
2.78 |
5.04 |
4.50 |
13.56 |
36.71 |
IE02 |
Southern |
0.54 |
0.54 |
1.89 |
3.56 |
5.36 |
12.62 |
36.23 |
IE03 |
Eastern and Midland |
0,35 |
0.35 |
1.65 |
2.73 |
5.50 |
14.32 |
35.96 |
(*) The coefficient of variation for actual hours worked should be calculated for the sum of actual hours worked in 1st and 2nd jobs, and restricted to those who actually worked 1 hour or more in the reference week. (**) The value is based on a CI of 95%. For the rates the CI should be given with 2 decimals. |
6.3. Non-sampling error |
[not requested for the LFS quality report] |
6.3.1. Coverage error |
Frame quality (under-coverage, over-coverage and misclassifications(b)) |
Under-coverage rate (%) |
Over-coverage rate (%) |
Misclassification rate (%) |
Comments: specification and impact on estimates(a) |
|
Undercoverage |
Overcoverage |
Misclassification(b) |
Reference on frame errors |
UNA
|
UNA |
UNA |
Census of Population is sampling frame |
UNA |
UNA |
UNA |
(a) Mention specifically which regions / population groups are not suitably represented in the sample. (b) Misclassification refers to statistical units having an erroneous classification where both the wrong and the correct one are within the target population. |
6.3.1.1. Over-coverage - rate |
[Over-coverage rate, please see concept 6.3.1 Coverage error in the LFS quality report] |
6.3.1.2. Common units - proportion |
[not requested for the LFS quality report] |
6.3.2. Measurement error |
Errors due to the medium (questionnaire) |
Was the questionnaire updated for the 2020 LFS operation? (Y/N) |
Synthetic description of the update |
Was the questionnaire tested? (Y/N) |
If the questionnaire has been tested, which kind of tests has been applied (pilot, cognitive, internal check)? |
Y |
The 2020 LFS questionnaire was updated on a quarterly basis to comply with EU regulation and for the inclusion and exclusion of Eurostat/National module which changed quarter on quarter. |
Y |
The 2020 LFS questionnaire was tested both cognitively and operationally. Cognitive testing was carried out by the Social Data Collection division of the CSO. The questionnaire was internallly tested by Social Data Collection division and IT division. This internal testing involved entering specific test cases into the questionnaire, recoding of question outcomes and reporting of findings of testing. Findings from testing where reviewed and where applicable amendments were made to the 2020 LFS Questionnaire. |
Main methods of reducing measurement errors |
Error source |
|
Respondent |
Letter introducing the survey (Y/N) |
Phone call for booking or introducing the survey (Y/N) |
Y |
N |
Interviewer |
Periodical training (at least 1 time per year) (Y/N) |
Feedbacks from interviewer (reports, debriefings, etc.) (Y/N) |
Y |
Y |
Fieldwork |
Monitoring directly by contacting the respondents after the fieldwork (Y/N) |
Monitoring directly by listening the interviews (Y/N) |
Monitoring remotely through performance indicators (Y/N) |
Y |
Y - CATI only |
Y |
Questionnaire |
Questionnaire in several languages (Y/N) |
On-line checks (for computer assisted interviews (Y/N) |
N |
Y |
Other / Comments |
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6.3.3. Non response error |
[not requested for the LFS quality report] |
6.3.3.1. Unit non-response - rate |
IN THIS SECTION INFORMATION REFERS TO THE FINAL SAMPLING UNITS *
Methods used for adjustments for statistical unit non-response |
Adjustment via weights (Y/N) |
Variables used for non-response adjustment |
Description of method |
Y |
Various |
The adjustment involves estimating response rates or propensities to respond as functions of characteristics available for responding and non-responding households, as well as characteristics of the areas where the households are located. Basically, the design weights have to be inflated by the inverse of the response propensities in order to compensate for the loss of units in the sample. Linking the LFS sample with the Census of Population at household level provides a set of auxiliary variables which are available for both responding and non-responding LFS households. These include a mix of personal characteristics as well as characteristics of the dwelling and location (e.g. gender, age, marital status, education, personal employment status, dwelling type, area etc.). This allows for the comparison of responding and non-responding households with respect to the characteristics available from the Census. This auxiliary information allows the use of “response propensities” to model non-response and adjust the grossing factors to compensate for non-response. The response propensities are calculated using a logistic regression model where the dependent variable (Y) is an indicator variables corresponding to response (if the household responded then Y=1 and if the household did not respond then Y=0) and the independent variables are the set of auxiliary variables available from the Census. The estimated response propensities are then used to form adjustment cells or strata which are made up of respondents and non-respondents with similar estimated response propensities. Respondents within each cell/stratum are then weighted by the inverse of the observed response rate in that cell. This non-response adjusted weight is then used to inflate the original survey design weight to account for non-response. This approach is referred to as response propensity classification. |
Substitution of non-responding units (Y/N) |
Substitution rate |
Criteria for substitution |
N |
NA |
NA |
Other methods (Y/N) |
Description of method |
N |
NA |
Non-response rates by survey mode. Annual average (% of the theoretical yearly sample by survey mode) |
Survey |
CAPI |
CATI |
PAPI |
CAWI |
POSTAL |
67.8 |
31.7 |
NA |
NA |
NA |
Divisions of non-response into categories. Quarterly data and annual average |
Quarter |
Non-response rate |
Total (%) |
of which: |
Refusals (%) |
Non-contacts (including people who migrated (or moved) internally or abroad) (%) |
of which people who migrated (or moved) internally or abroad (%) |
1 |
54.7 |
11.0 |
28.7 |
Not available |
2 |
59.5 |
10.4 |
60 |
Not available |
3 |
60.2 |
9.8 |
67.6 |
Not available |
4 |
60.3 |
8.8 |
71.1 |
Not available |
Annual |
57.9 |
10.1 |
58.3 |
Not available |
Units who refused to participate in the survey (Please indicate the number of the units concerned in the cells where the wave is mentioned) |
Subsample |
Quarter1_2020 |
Quarter2_2020 |
Quarter3_2020 |
Quarter4_2020 |
Subsample_Q1_2019 |
203 |
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|
Subsample_Q2_2019 |
373 |
416 |
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|
Subsample_Q3_2019 |
405 |
490 |
515 |
|
Subsample_Q4_2019 |
489 |
566 |
614 |
611 |
Subsample_Q1_2020 |
482 |
474 |
516 |
571 |
Subsample_Q2_2020 |
|
92 |
169 |
225 |
Subsample_Q3_2020 |
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|
107 |
164 |
Subsample_Q4_2020 |
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|
153 |
Total in absolute numbers |
1952 |
2038 |
1921 |
1724 |
Total in % of theoretical quarterly sample |
6.0 |
6.3 |
5.92 |
5.3 |
Units who were not contacted (including people who migrated (or moved) internally or abroad) (Please indicate the number of units only in the cells where the wave is mentioned) |
Subsample |
Quarter1_2020 |
Quarter2_2020 |
Quarter3_2020 |
Quarter4_2020 |
Subsample_Q1_2019 |
582 |
|
|
|
Subsample_Q2_2019 |
817 |
1206 |
|
|
Subsample_Q3_2019 |
910 |
1569 |
1518 |
|
Subsample_Q4_2019 |
1214 |
2048 |
2015 |
1810 |
Subsample_Q1_2020 |
1578 |
2729 |
2491 |
2338 |
Subsample_Q2_2020 |
|
4032 |
3405 |
3116 |
Subsample_Q3_2020 |
|
|
3803 |
3237 |
Subsample_Q4_2020 |
|
|
|
3423 |
Total in absolute numbers |
5101 |
11584 |
13232 |
13924 |
Total in % of theoretical quarterly sample |
15.7 |
35.7 |
40.8 |
42.9 |
of which people who migrated (or moved) internally or abroad) (Please indicate the number of units only in the cells where the wave is mentioned) |
Subsample |
Quarter1_2020 |
Quarter2_2020 |
Quarter3_2020 |
Quarter4_2020 |
Subsample_Q1_2019 |
UNA |
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Subsample_Q2_2019 |
UNA |
UNA |
|
|
Subsample_Q3_2019 |
UNA |
UNA |
UNA |
|
Subsample_Q4_2019 |
UNA |
UNA |
UNA |
UNA |
Subsample_Q1_2020 |
UNA |
UNA |
UNA |
UNA |
Subsample_Q2_2020 |
|
UNA |
UNA |
UNA |
Subsample_Q3_2020 |
|
|
UNA |
UNA |
Subsample_Q4_2020 |
|
|
|
UNA |
Total in absolute numbers |
Total |
Total |
Total |
Total |
Total in % of theoretical quarterly sample |
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Non-response rates. Annual averages (% of the theoretical yearly sample) |
NUTS-2 region (code + name) |
Non response rate (%) |
IE01 (Nothern and Western) |
62.2 |
IE02 (Southern) |
56.1 |
IE03 (Eastern & Miland) |
57.3 |
* If the final sampling unit is the household it must be considered as responding unit even in case of some household members (not all) do not answer the interview |
6.3.3.2. Item non-response - rate |
Item non-response (*) - Quarterly data (Compared to the variables defined by the Commission Regulation (EC) No 377/2008) |
Variable status |
Column |
Identifier |
Quarter 1 |
Quarter 2 |
Quarter 3 |
Quarter 4 |
Short comments on reasons for non-available statistics and prospects for future solutions |
Compulsory / optional |
compulsory |
Col_054 |
TEMPDUR |
21 |
20.2 |
25.7 |
26.6 |
|
compulsory |
Col_065/66 |
HWOVERP |
11.4 |
24.6 |
15.8 |
15.2 |
|
compulsory |
Col_067/68 |
HWOVERPU |
11.6 |
24.6 |
16.3 |
15.5 |
|
compulsory |
Col_073/74 |
HWWISH |
80.5 |
80.2 |
80.6 |
82.5 |
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Item non-response - Annual data (Compared to the variables defined by the Commission Regulation (EC) No 377/2008) |
Variable status |
Column |
Identifier |
This reference year |
Short comments on reasons for non-available statistics and prospects for future solutions |
compulsory |
Col_053 |
TEMPREAS |
33.7 |
|
compulsory |
Col_118 - Employed |
AVAIREAS |
94.6 |
|
compulsory |
Col_118 - Not employed |
AVAIREAS |
14.4 |
|
compulsory |
Col_121 |
REGISTER |
100 |
Not currently collected |
compulsory |
Col_146 |
WSTAT1Y |
100 |
Not currently collected |
compulsory |
Col_150/151 |
COUNTR1Y |
100 |
Not currently collected |
compulsory |
Col_152/153 |
REGION1Y |
C |
|
compulsory |
Col_154/155 |
INCDECIL |
58.6 |
Question only asked to direct respondents due to sensitive nature of question |
compulsory |
Col_200/203 |
HATYEAR |
14.6 |
Not stated answers from respondents |
optional |
Col_132 |
COURPURP |
100 |
Not stated answers arise from respondents |
optional |
Col_133/135 |
COURFILD |
100 |
Not currently collected |
optional |
Col_136 |
COURWORH |
100 |
Not stated answers arise from respondents |
(*) "C" means all the records have the same value different from missing. |
6.3.4. Processing error |
Editing of statistical item non-response |
Do you apply some data editing procedure to detect and correct errors? (Y/N) |
Overall editing rate (Observations with at least one item changed / Total Observations ) |
Y, the routing of the survey questionnaire ensures that all relevant questions to the individual are answered. The survey cannot proceed until they are answered. A series of edit checks are carried out on family unit coding and these are addressed manually. |
0.8% |
|
6.3.4.1. Imputation - rate |
Imputation of statistical item non-response |
Are all or part of the variables with item non response imputed? (Y/N) |
Overall imputation rate (Observations with at least one item imputed / Total Observations ) |
N |
NA |
Main variables |
Imputation rate |
Describe method used, mentioning which auxiliary information or stratification is used |
NA |
NA |
NA |
|
6.3.5. Model assumption error |
[not requested for the LFS quality report] |
6.4. Seasonal adjustment |
Do you apply any seasonal adjustment to the LFS Series? (Y/N) |
If Yes, is your adopted methodology compliant with the ESS guidelines on seasonal adjustment? (ref. http://ec.europa.eu/eurostat/web/research-methodology/seasonal-adjustment) (Y/N) |
If Yes, are you compliant with the Eurostat/ECB recommendation on Jdemetra+ as software for conducting seasonal adjustment of official statistics. (ref. http://ec.europa.eu/eurostat/web/ess/-/jdemetra-officially-recommended-as-software-for-the-seasonal-adjustment-of-official-statistics) (Y/N) |
If Not, please provide a description of the used methods and tools |
Y |
Yes |
The seasonal adjustment of the LFS is carried out using X-13-ARIMA |
The seasonal adjustment of data from the QNHS between Q2 2011 and Q2 2017 was completed by applying the X-12-ARIMA model, developed by the U.S. Census Bureau. This seasonal adjustment methodology was reviewed following the introduction of the new LFS in Q3 2017. As a result of this review, from Q3 2017 onwards, the seasonal adjustment of the LFS is conducted using the X-13ARIMA-SEATS software also developed by the U.S. Census Bureau. The adjustments are carried out by applying the X-13-ARIMA model to the unadjusted data. This methodology estimates seasonal factors while also taking into consideration factors that impact on the quality of the seasonal adjustment, such as:
- Calendar effects e.g. the timing of Easter
- Outliers, temporary changes, and level shifts in the series
For additional information on the use of X-13ARIMA-SEATS see: http://www.census.gov/srd/www/x13as/ Seasonal adjustment is conducted using the direct approach, where each individual series is independently adjusted. As a result of this direct seasonal adjustment approach it should be noted that the sum of any component series may not be equal to seasonally adjusted series to which these components belong, e.g. the seasonally adjusted number of males in employment and the seasonally adjusted number of females in employment will not necessarily add up to the total employment on a seasonally adjusted basis. The X-13-ARIMA method has the X-11 moving averages process at its core, but builds on this by providing options for pre-treating the series using a regARIMA approach for prior adjustment and series extension. In essence, this methodology will estimate seasonal factors while taking account of calendar effects (e.g. timing of Easter), outliers, temporary changes and level shifts. The seasonal adjustment is designed and implemented in full accordance with the ESS Guidelines (2015). |
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6.5. Data revision - policy |
|
6.6. Data revision - practice |
[not requested for the LFS quality report] |
6.6.1. Data revision - average size |
[not requested for the LFS quality report] |