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 |
1 300 |
3 500 |
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 |
1.06 |
0.56 |
3.25 |
2.15 |
1.90 |
4.49 |
0.26 |
SE |
39,996 |
0.003 |
10 |
16.205 |
0.003 |
0.016 |
0.106 |
CI(**) |
3,687,815 - 3,844,669 |
60.5 - 61.8 |
298,994 - 339,744 |
723,208 - 786,756 |
15.7 - 16.9 |
31.9 - 38.1 |
40.1 - 40.5 |
Description of the assumption underlying the denominator for the calculation of the CV for the employment rate |
The employment rate is computed under the assumption that the total poulation is a random variable (because due to the age groups we use for post stratification. the total population 20 - 64 is not known) |
Reference on software used: |
Reference on method of estimation: |
SPSS complex samples |
replicated samples estimation |
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 |
GR30 |
Attiki |
1.96 |
1.04 |
5.83 |
4.16 |
3.86 |
11.59 |
0.46 |
GR41 |
Voreio Aigaio |
5.26 |
2.3 |
17.13 |
10.12 |
8.53 |
17.07 |
1.29 |
GR42 |
Notio Aigaio |
5.55 |
2.66 |
15.34 |
12.58 |
10.6 |
18.82 |
1.68 |
GR43 |
Kriti |
3.6 |
1.67 |
11.26 |
7.24 |
5.79 |
12.95 |
0.73 |
GR51 |
Anatoliki Makedonia. Thraki |
3.52 |
2.15 |
8.45 |
7.91 |
6.96 |
13.39 |
0.93 |
GR52 |
Kentriki Makedonia |
2.5 |
1.37 |
7.26 |
4.72 |
4.07 |
11.01 |
0.64 |
GR53 |
Dytiki Makedonia |
5.23 |
2.99 |
15.32 |
9.52 |
7.04 |
17.84 |
1.5 |
GR54 |
Ipeiros |
5.15 |
2.7 |
14.04 |
8.92 |
7.54 |
19.89 |
1.15 |
GR61 |
Thessalia |
4.42 |
2.29 |
11.81 |
9.21 |
7.95 |
14.21 |
1.29 |
GR62 |
Ionia Nisia |
5.76 |
2.94 |
18.32 |
10.81 |
9.49 |
22.01 |
1.2 |
GR63 |
Dytiki Ellada |
4.87 |
2.52 |
11.44 |
8.06 |
6.59 |
11.03 |
1.09 |
GR64 |
Sterea Ellada |
3.96 |
2.42 |
14.5 |
10.31 |
8.84 |
11.01 |
1.05 |
GR65 |
Peloponnisos |
3.89 |
1.67 |
13.04 |
7.7 |
6.95 |
17.18 |
0.92 |
(*) 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 |
About 1.5% |
About 7% |
UNA |
Population living in collective households, or in dwellings outside the borders of builded areas is not covered. Frames are compiled at census, and sampling rates are based at census population. Frames are updated at the first time when the primary sampling units are selected but not at subsequent waves. |
The sample in Greek LFS is a sample of dwellings. The percentage of over-coverage is computed as the percentage of dwellings that are either used as "secondary residence" of the household or they are used solely for business purposes (e.g, a doctor's office). |
UNA |
The selection probabilities of PSU’s are based on the 2011 census data. Since then, significant changes have occurred in the Greek population (most important is immigration due to the economic crisis). Thus, there are likely to be issues about the accuracy of the design weights of the PSU’s. |
(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 |
nErrors 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)? |
N |
NA |
N |
NA |
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 |
Y (but not in the first wave) |
Interviewer |
Periodical training (at least 1 time per year) (Y/N) |
Feedbacks from interviewer (reports, debriefings, etc.) (Y/N) |
Y (only for ad hoc modules) |
N (only in informal setting) |
Fieldwork |
Monitoring directly by contacting the respondents after the fieldwork (Y/N) |
Monitoring directly listening interviews, (Y/N) |
Monitoring remotely through performance indicators (Y/N) |
N |
N |
Y (Rate of non-responce/identification of primary sampling units with zero changes from quarter to quarter) |
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 |
Non-response adjustment is implemented at primary sampling unit level |
The design weights are multiplied by (Number of eligible dwellings in primary sampling units/Number of responding households in the sampling unit) |
Substitution of non-responding units (Y/N) |
Substitution rate |
Criteria for substitution |
N |
NA |
NA |
Other methods (Y/N) |
Description of method |
N |
NA |
Rates of non- response by survey mode. Annual average |
Survey |
CAPI |
CATI |
PAPI |
CAWI |
PO |
50.5 |
NA |
35.0 |
NA |
NA |
Non-response rates by survey mode. Annual average (% of the theoretical yearly sample by survey mode) |
Quarter |
Non response rate |
Total (%) |
Refusals (%) |
Non-contacts (including people who migrated (or moved) internally or abroad) (%) |
of which people who migrated (or moved) internally or abroad (%) |
1 |
32.6 |
9.3 |
12.3 |
UNA |
2 |
33.3 |
9.5 |
12.3 |
UNA |
3 |
36.3 |
10.3 |
13.9 |
UNA |
4 |
39.5 |
11.2 |
15.3 |
UNA |
Annual |
35.5 |
10.0 |
13.5 |
UNA |
Units who refused to participate in the survey (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_Q4_2018 |
589 |
584 |
|
|
Subsample_Q1_2019 |
553 |
579 |
|
|
Subsample_Q2_2019 |
524 |
544 |
539 |
|
Subsample_Q3_2019 |
557 |
569 |
577 |
596 |
Subsample_Q4_2019 |
529 |
535 |
545 |
565 |
Subsample_Q1_2020 |
539 |
552 |
579 |
593 |
Subsample_Q2_2020 |
|
30 |
716 |
741 |
Subsample_Q3_2020 |
|
|
733 |
760 |
Subsample_Q4_2020 |
|
|
|
764 |
Total in absolute numbers |
3291 |
3393 |
3689 |
4019 |
Total in % of theoretical quarterly sample |
9.3 |
9.5 |
10.3 |
11.2 |
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_Q4_2018 |
531 |
563 |
|
|
Subsample_Q1_2019 |
567 |
573 |
|
|
Subsample_Q2_2019 |
766 |
787 |
781 |
|
Subsample_Q3_2019 |
706 |
704 |
674 |
678 |
Subsample_Q4_2019 |
613 |
638 |
619 |
607 |
Subsample_Q1_2020 |
1224 |
1172 |
1070 |
1104 |
Subsample_Q2_2020 |
|
13 |
867 |
920 |
Subsample_Q3_2020 |
|
|
955 |
981 |
Subsample_Q4_2020 |
|
|
|
1187 |
Total in absolute numbers |
4407 |
4450 |
4966 |
5477 |
Total in % of theoretical quarterly sample |
12.3 |
12.3 |
13.9 |
15.3 |
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_Q4_2018 |
NA |
|
|
|
Subsample_Q1_2019 |
NA |
NA |
|
|
Subsample_Q2_2019 |
NA |
NA |
NA |
|
Subsample_Q3_2019 |
NA |
NA |
NA |
NA |
Subsample_Q4_2019 |
NA |
NA |
NA |
NA |
Subsample_Q1_2020 |
NA |
NA |
NA |
NA |
Subsample_Q2_2020 |
|
NA |
NA |
NA |
Subsample_Q3_2020 |
|
|
NA |
NA |
Subsample_Q4_2020 |
|
|
|
NA |
Total in absolute numbers |
NA |
NA |
NA |
NA |
Total in % of theoretical quarterly sample |
NA |
NA |
NA |
NA |
Non-response rates. Annual averages (% of the theoretical yearly sample) |
NUTS-2 region (code + name) |
Non response rate (%) |
GR30 Attiki |
53.0 |
GR41 Voreio Aigaio |
19.9 |
GR42 Notio Aigaio |
25.6 |
GR43 Kriti |
31.1 |
GR51 Anatoliki Makedonia, Thraki |
26.1 |
GR52 Kentriki Makedonia |
31.7 |
GR53 Dytiki Makedonia |
22.6 |
GR54 Ipeiros |
40.0 |
GR61 Thessalia |
33.4 |
GR62 Ionia Nisia |
37.0 |
GR63 Dytiki Ellada |
33.4 |
GR64 Sterea Ellada |
29.9 |
GR65 Peloponnisos |
20.6 |
* 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_039/40 |
COUNTRYW |
. |
. |
C |
. |
In general, LFS find very few people working abroad |
compulsory |
Col_110 - Employed |
METHODH |
. |
. |
. |
C |
There are answers in this category (72). The small number of cases (half of the usual in previous years) probably reflects the consequenses of COVID crisis which prevents people from starting there own business |
compulsory |
Col_111 - Employed |
METHODI |
. |
. |
C |
. |
There are answers in this category (84). The small number of cases (half of the usual in previous years) probably reflects the consequenses of COVID crisis which prevents people from starting there own business |
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 |
12.6 |
In the Greek Questionnaire there is the (residual) answer category "Did not specify the reason" (which is converted in "No answer"). However, as non-response varies considerably across areas, recommendations have been given to staff and interviewers in order to get more accurate answers. |
compulsory |
Col_118 - Employed |
AVAIREAS |
18.5 |
In the Greek Questionnaire there is the (residual) answer category "Did not specify the reason" (which is converted in "No answer"). However, as non-response varies considerably across areas, recommendations have been given to staff and interviewers in order to get more accurate answers. |
compulsory |
Col_154/155 |
INCDECIL |
11.7 |
It is a sensitive question in which people tend to refuse to answer. In order to reduce non-response the 2019 questionnaire also includes income bands and as a result the non response decreased (from about 15% to 10.9%) |
|
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 |
UNA |
|
6.3.4.1. Imputation - rate |
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 |
|
|
6.3.5. Model assumption error |
[not requested for the LFS quality report] |
6.4. Seasonal adjustment |
|
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] |