Structure of earnings survey 2010 (earn_ses2010)

National Reference Metadata in ESS Standard for Quality Reports Structure (ESQRS)

Compiling agency: Statistics Belgium


Eurostat metadata
Reference metadata
1. Contact
2. Statistical presentation
3. Statistical processing
4. Quality management
5. Relevance
6. Accuracy and reliability
7. Timeliness and punctuality
8. Coherence and comparability
9. Accessibility and clarity
10. Cost and Burden
11. Confidentiality
12. Comment
Related Metadata
Annexes (including footnotes)
 



For any question on data and metadata, please contact: Eurostat user support

Download


1. Contact Top
1.1. Contact organisation

Statistics Belgium

1.2. Contact organisation unit

Labour Market Statistics

1.5. Contact mail address

North Gate
Koning Albert II-laan 16 

1000 Brussels


2. Statistical presentation Top
2.1. Data description

[Not requested]

2.2. Classification system

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.3. Coverage - sector

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.4. Statistical concepts and definitions

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.5. Statistical unit

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.6. Statistical population

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.7. Reference area

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.8. Coverage - Time

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

2.9. Base period

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.


3. Statistical processing Top
3.1. Source data

Different sources of the SES

In Belgium, the emphasis is clearly shifting towards an intensive use of administrative sources wherever possible. For this survey three important administrative sources were used:

  • The national register of enterprises (DBRIS)
  • The earnings and working hours database of the National Office for Social Security (ONSS)
  • The national register of individuals (RN)

The questionnaire only included these variables where no information was available from the administrative sources (NSI). The table below gives an overview of the different Eurostat variables and the way Statistics Belgium obtained them:

 

Source of each variable

 

Variable Eurostat DBRIS ONSS RN NSI
Region x      
Size of the enterprise x      
Economic activity x      
Economic and financial control   x    
Collective pay agreement   x    
Number of employees in the local unit x      
Grossing-up factor for local units x      
Sex     x  
Age     x  
Occupation       x
Level of education and training       x
Length of service in the enterprise       x
Full-time or part-time employee   x    
% share of a full-timer’s normal hours   x    
Type of employment contract       x
Number of weeks to which the gross annual earnings relate   x    
Number of hours paid during the reference month       x
Number of overtime hours paid in the
reference month
      x
Annual days of holiday leave       x
Gross annual earnings in the reference year   x    
Annual bonuses and allowances not
paid every pay period
  x    
Gross earnings in the reference month       x
Earnings related to overtime       x
Special payments for shift work       x
Average gross hourly earnings in the
reference month
      x
Grossing-up factor for employees       x

 

Sampling technique

The SES 2010 was conducted based on a two-stage sampling approach. In the first stage, a stratified random sample of local units was drawn. The stratification criteria were the economic activity, the number of employees and the region of the local unit. The questionnaire, the explanation and a list of local units for which the survey needed to be filled in were sent to the head offices of the selected local units. We chose not to send the questionnaire to every local unit in the sample, since a central pay-roll administration is usually responsible for the payment of all wages. The possibility of a mistake by the enterprise, for example by taking the wrong local unit, is very limited, because every local unit in Belgium has its own unique administrative number. The continuously updated business register was used to define the sampling frame. The universe consisted of 55,989 local units. Eventually 9,420 local
units were included in the sample survey. The chances of selection largely depended on the number of employees a local unit has. In the second stage, the local unit had to select a number of employees according to the instructions in the explanation. Local units with fewer than 300 employees had to select a proportion of their total number of workers:

 

Number of selected wage earners for local units with fewer than 300 employees 

 

Total number of employees Proportion
Fewer than 20 100%
20 - 49 50%
50 - 99 25%
100 - 199 14.3%
200 - 299 10%

 

Local units with 300 employees or more needed to select a fixed absolute number of workers:

Number of selected wage earners for local units with at least 300 employees

 

Total number of employees Number of wage earners to be selected
300 - 349 30
350 - 449 35
450 - 549 40
550 - 699 45
700 - 899 50
900 - 1,099 55
1,100 - 1,299 60
1,300 - 1,599 65
1,600 - 1,999 75
2,000 - 2,999 85
3,000 - 3,999 100
4,000 - 4,999 115
5,000 - 6,499 130
6,500 - 7,999 145
8,000 - 9,499 160
9,500 - 11,999 180
12,000 or more 200

 

To ensure that the sample was drawn on a coincidental basis, every local unit received a letter of the alphabet. The local unit had to start its selection of employees with the wage earner whose surname began with that letter. If the number of wage earners was not reached at the letter ‘Z’, the selection continued with the letter ‘A’. No stratification criteria were used in this second stage, because we wanted to keep this step as easy as possible for the respondents.

3.2. Frequency of data collection

[Not requested]

3.3. Data collection

[Not requested]

3.4. Data validation

[Not requested]

3.5. Data compilation

[Not requested]

3.6. Adjustment

[Not requested]


4. Quality management Top
4.1. Quality assurance

Not available.
New concept added with the migration to SIMS 2.0.
Information (content) will be available after the next collection.

4.2. Quality management - assessment

[Not requested]


5. Relevance Top
5.1. Relevance - User Needs

The results and data of the Structure of Earnings Survey (SES) are often used by the Belgian general public. Students, research centres, universities, trade unions, the media, private companies and public administration institutions can all be considered as important users of the SES.

One reason for this interest from a wide range of users comes from the large survey sample. Because of these large numbers, the SES can give a correct image of the gross earnings by several independent variables. Together with the Labour Force Survey, the SES is for example the only national source where earnings can be linked with important personal characteristics such as the level of education or the occupation of the worker. The rather unique combination between individual features on the one hand and enterprise characteristics on the other hand can also explain the broad use of the SES.

 

Use of SES – variables in tailor-made tables

 

Column number Variable name Frequency
B42 Gross earnings in the reference month 180
A13 Economic activity 122
B23 Occupation in the reference month 81
B27 Full-time or part-time employee 77
B21 Sex 64
A11 Region 49
B43 Average gross hourly earnings 41
B25 Level of education and training 38
B22 Age 30
B41 Gross annual earnings 25
B26 Length of service in enterprise 22
A15 Collective pay agreement 16
A12 Size of the enterprise 8
B32 Number of hours paid 7
B411 Annual bonuses and allowances 7
B271 % share of a full-timer’s normal hours 5
B321 Number of overtime hours 4
B421 Earnings related to overtime 4
A14 Form of economic and financial control 3
B28 Type of employment contract 2
B422 Special payments for shift work 2
B31 Number of weeks to which B41 relates 0
B33 Annual days of holiday leave 0

 

To indicate the importance of a variable for the general public, the above table gives an overview of the number of times a variable has been used in tailor-made tables. These tables are made to cover specific demands. On a yearly basis, our service receives around 250 demands for such tailor-made tables. Demands for microdata are not included in this list, as these demands normally contain almost every variable.

The most popular variable is by far gross monthly earnings during the reference month. Other frequently asked variables are economic activity, occupation, sex and the variable indicating whether an employee is working on a full-time or part-time basis. We also notice a limited interest for several other variables and some of them, such as the annual days of holiday leave, are not even included in any of the tailormade tables.

 

Overview of the most important users of the SES

In Belgium, the Structure of Earnings Survey is organised on a yearly basis. Therefore, this survey has many structural users, who make use of the results every year. The next section gives an overview of the main users and their projects.

 

  • Every year ‘The Institute for the Equality of Women and Men’ publishes a detailed report concerning the gender pay gap in Belgium. Since the beginning of this report, the SES has been used as the source of the necessary figures. The advantage of the SES is that this survey makes it possible to calculate several breakdowns, e.g. by gender. In Belgium, this report has an important reporting and policy recommendation function.
  • The Federal Public Service Finance calculates the average tax wedges every year. To make international comparisons possible, a representative wage is used. This international concept corresponds to the average wage of full-time wage earners working in the NACE sections B-N. In other words, the FPS Finance calculates the average wages in Belgium on the basis of the SES. This survey has another important advantage. The data make it possible to take into account the impact of structural changes on the labour market, such
    as the shift to part time work.
  • The Department of Applied Economics of the Free University of Brussels conducts research into the impact of wage dispersion on the performance of enterprises. For this research, the SES variables are linked to variables from the Structural Business Survey, such as turn-over or profit.
  • The Federal Planning Bureau manages a labour market database that was created within the framework of the European EU KLEMS productivity measurement project and serves as the backbone for a Social Accounting Matrix compatible with Belgian National Accounts aggregates. Although this database is primarily grounded on administrative data, some information, such as the earnings by level of education or occupation, is only available in
    the SES.
  • The Central Economic Council, an advisory body for the business community, uses the SES to support their reports with the necessary figures. The wage and the labour time data from the SES are also used as an input for social bargaining.
5.2. Relevance - User Satisfaction

Description of the gaps and less relevant parts

Although almost all demands can be met by the existing information and variables, there is still much interest in more personal characteristics of the workers. Aspects such as nationality or household situation of the worker often influence the earnings and labour time. Also in the framework of the gender pay gap this information would be very useful.

5.3. Completeness

[Not requested]

5.3.1. Data completeness - rate

[Not requested]


6. Accuracy and reliability Top

-

6.1. Accuracy - overall

[Not requested]

6.2. Sampling error

See 6.2.1. for more information concerning the sampling errors.

6.2.1. Sampling error - indicators

In general, the coefficients of variation are low, although there are several exceptions. Especially in the breakdowns with a limited number of workers, it is almost impossible to organise a survey in which these groups are measured correctly without being exhaustive. This problem appears in several NACE-sections, in the ISCO 1, in the ISCED 6 and finally in the age groups under 20 and 60 years and over.

 

Please see the attached documents Coefficients of variation.



Annexes:
Coefficients of variation
6.3. Non-sampling error

See further for more details concerning the non-sampling errors.

6.3.1. Coverage error

There were no differences between the reference and the study population. The universe and the sample survey were drawn up from the most recent business register available at the time. This register gives an overview of all enterprises and local units that had wage earners in service on 30 September 2010.

Under or over coverage was therefore possible but would have a very limited impact, as only those local units who started or ceased their activities during the month of October could be affected. No official numbers were available for under coverage. The number of selected local units that did not exist anymore at the moment of the survey or of which the number of employees had been reduced to fewer than 10 wage earners, amounted to 106 local units, or 1.1% of the sample survey.

With regard to the size of the enterprise Belgium chose to exclude the small enterprises with fewer than ten employees. We also excluded the NACE section O in our sample. This means that the Belgian datasets only include the local units covered by the Regulation.

6.3.1.1. Over-coverage - rate

-

6.3.1.2. Common units - proportion

[Not requested]

6.3.2. Measurement error

In order to detect outliers and other quality problems, several aggregated checks were integrated into the different data collection tools. More complicated inconsistency problems were solved internally or by contacting the local unit on a bilateral basis.

6.3.3. Non response error

The unit response rate for the entire survey amounts to 82 %. As indicated in the table below, these rates vary substantially between the different economic activities. Especially in the non-business economy the response rates are relatively low.

 

Unit response rate by economic activity

Principal economic activity of the local unit Unit response rate
X8 95%
X9 100%
X10 80%
X11 95%
X12 83%
X13 82%
X14 84%
X15 100%
X16 80%
X17 88%
X18 77%
X19 100%
X20 83%
X21 88%
X22 82%
X23 88%
X24 79%
X25 84%
X26 89%
X27 81%
X28 86%
X29 84%
X30 86%
X31 80%
X32 85%
X33 83%
X35 90%
X36 61%
X37 82%
X38 87%
X39 91%
X41 79%
X42 80%
X43 82%
X45 78%
X46 78%
X47 76%
X49 86%
X50 73%
X51 88%
X52 84%
X53 100%
X55 71%
X56 69%
X58 86%
X59 94%
X60 88%
X61 82%
X62 81%
X63 87%
X64 93%
X65 87%
X66 75%
X68 64%
X69 89%
X70 83%
X71 79%
X72 89%
X73 72%
X74 76%
X75 91%
X77 82%
X78 81%
X79 82%
X80 88%
X81 80%
X82 79%
X85 100%
X86 70%
X87 77%
X88 79%
X90 60%
X91 78%
X92 64%
X93 72%
X94 71%
X95 80%
X96 56%
Total 82%
6.3.3.1. Unit non-response - rate

[Not requested]

6.3.3.2. Item non-response - rate

[Not requested]

6.3.4. Processing error

See further for more details.

6.3.4.1. Imputation - rate

Item imputation rate

Data completeness is one of the advantages of an administrative register. Consequently, for those variables of which the information is derived from existing datasets, the item imputation rates equals to 0 %.

For the variables included in the questionnaire, the item imputation rate is highest for the level of education. For 4,307 workers or 3.1 % of the cases, this information was imputed. Enterprises often inform us about the difficulties to obtain this specific piece of information. In general, the level of education is less relevant for enterprises, since their workers can compensate a lower degree of education by experience or other skills. This information therefore often remains uncentralised.

Additionally, with a rate of 2.1 %, the annual days of holiday leave are often imputed. The calculation of these days is often complex, since several aspects such as age or working hours must be taken into account.

For all the other variables the item imputation rates is less than 0.2 %.

 

Overall imputation rate

Given the very low item imputation rates, the overall rate is also negligible. Here all the information at the level of the local unit is derived from administrative datasets, the overall imputation rate for Record A equals to 0 %. Also for Record B this imputation rate is limited to 0.6 %.

6.3.5. Model assumption error

No assumptions are made.

6.4. Seasonal adjustment

[Not requested]

6.5. Data revision - policy

[Not requested]

6.6. Data revision - practice

[Not requested]

6.6.1. Data revision - average size

[Not requested]


7. Timeliness and punctuality Top
7.1. Timeliness

The two records with the thoroughly checked and internally approved data were sent to Eurostat on 28 June 2012. The data delivery took place before the deadline stipulated by the Regulation.

7.1.1. Time lag - first result

[Not requested]

7.1.2. Time lag - final result

[Not requested]

7.2. Punctuality

The field work started by sending the questionnaires on 15 January 2011. At first the respondents/ enterprises had time until the end of February to fill in the questionnaire. Respondents who did not answer within this deadline received a first reminder early March and a second in April.

More intensive contact attempts were held in May and June. They aimed at convincing respondents to participate and at increasing the unit response rate. For the most important local units phone contacts were replaced with a visit. An employee of Statistics Belgium could then help respondents fill in the questionnaire when this was necessary. The field work was closed in September 2011, i.e. eight
months after the start.

Data processing started as soon as the questionnaires were sent to the respondents. For the overall quality of the data, we aim to check the received data as soon as possible. This allows us to contact the respondent within an acceptable time span when errors or missing items are detected.

Besides the survey data, some administrative sources were used to calculate the Eurostat variables. Even if these sources have several advantages, such as the correctness and the completeness of the data, they also have an important disadvantage: some of them were not received before spring 2012.

The final results of the SES 2010 were published in July 2012.

7.2.1. Punctuality - delivery and publication

[Not requested]


8. Coherence and comparability Top
8.1. Comparability - geographical

Belgium has strictly followed the content of the Regulation. Geographical comparability should therefore be ensured.

A remark for education professionals is nevertheless in place. In Belgium the contractual labour time of these professionals differs substantially from the effectively performed labour time. This group of employees works several non-paid hours per week preparing classes and correcting student exams. This rather limited number of hours paid influences the amount of the hourly earnings, so variable B32 is used as the denominator there. The hourly earnings for this specific group of employees are therefore rather high and could differ substantially from the earnings available for other countries.

8.1.1. Asymmetry for mirror flow statistics - coefficient

[Not requested]

8.2. Comparability - over time

Compared with the SES 2006, the SES 2010 uses another classification for the variables concerning the economic activity of the local unit and for the occupation of the worker. Because the economic activity is one of the three stratification criteria, this change in classification could influence the comparability of the results between these two reference years.

Additionally, the surveys with reference years 2006 and 2010 differ from the SES 2002 in two ways:

  1. In 2002, the main economic activity of the local unit was unknown. For this survey we worked with the assumption that the economic activity of the local unit was exactly the same as the activity of the enterprise to which it belonged. Since the SES 2006, this problem has been solved, so one enterprise could have local units executing different activities.
  2. In 2002, the definition of a local unit did not correspond with the concept used by Eurostat. According to the Belgian definition, a company could never have more than one local unit with the same economic activity in one municipality. This meant that in 2002 a company was supposed to count up the wage earners of all its local units in every municipality. In the meantime, the Belgian definition of a local unit was adapted to the European rules. Since the SES 2006, it is therefore possible that one enterprise has several local units with the same activity in the same municipality.
8.2.1. Length of comparable time series

[Not requested]

8.3. Coherence - cross domain

The following table compares the survey’s variable “Gross annual earnings in the reference year” with the variable “wages and salaries” from the national accounts. Comparisons between these two sources should nevertheless be done carefully, because several differences concerning the target population and the followed methodology exist. The figures of the national accounts include for example businesses with fewer than ten employees, while these enterprises are excluded in the SES. Given the above remarks, the figures are nevertheless comparable for the majority of economic activities. The biggest variation can be found in section L. However, these real estate activities only count a limited number of workers. It could also be mentioned that in this NACE section 60 % of the workers are employed in small enterprises excluded from the SES sample.

 

Comparison between the SES and the national accounts

 

NACE section Sruvey variable B41 National accounts variable D11
B 42.153 39.983
C 42.601 42.875
D 69.764 76.486
E 41.413 43.683
F 37.126 32.323
G 37.493 34.669
H 38.849 36.886
I 25.059 20.830
J 51.347 53.316
K 55.499 56.881
L 44.324 29.795
M 53.840 49.712
N 22.297 23.111
P 44.046 42.278
Q 36.297 29.239
R 33.761 29.654
S 36.181 29.985
8.4. Coherence - sub annual and annual statistics

[Not requested]

8.5. Coherence - National Accounts

[Not requested]

8.6. Coherence - internal

[Not requested]


9. Accessibility and clarity Top
9.1. Dissemination format - News release

Every year, Statistics Belgium publishes a press release to explain and illustrate the main results of the SES. This communiqué is generally broadly covered by Belgian newspapers and news agencies. Moreover, the SES is also used for other press releases, in which the data are combined with the results from other surveys. A press release dedicated to singles is a recent example of this approach.

9.2. Dissemination format - Publications

In Belgium, the SES is organised on a yearly basis and is therefore well-known by the general public. Nevertheless, each year we use several channels to disseminate the SES results.

 

The results of the SES are also integrated in several publications. Some key results are included in the annual key figures published by Statistics Belgium. A similar initiative is taken by the Labour Market section. This division of Statistics Belgium publishes their own yearbook, containing more detailed information on the most important figures of the different statistics. Finally, also the annual Gender Pay Gap Report is worth mentioning. This elaborate publication describes the differences between men and women in the Belgian labour market. The SES is by far the most important source of this report.

9.3. Dissemination format - online database

The main channel to communicate the results is the dedicated section on the website of Statistics Belgium. This webpage contains the most popular aggregated tables, but visitors can also compose their own tables with our dynamic application. The earnings information is one of the most popular sections of the website, with more than 1,000 unique visitors every month.

9.3.1. Data tables - consultations

[Not requested]

9.4. Dissemination format - microdata access

For users needing more detailed and unique data, Statistics Belgium offers two possibilities. On the one hand, we produce aggregated tables according to the preferences of our users. On a yearly basis, our service receives around 250 demands for such tailor-made tables. On the other hand, we give researchers the possibility to use micro-data for their research projects. The number of demands for
these data is limited to a few projects every year.

9.5. Dissemination format - other

-

9.6. Documentation on methodology

The metadata are published on the website of Statistics Belgium.

9.7. Quality management - documentation

[Not requested]

9.7.1. Metadata completeness - rate

[Not requested]

9.7.2. Metadata - consultations

[Not requested]


10. Cost and Burden Top

[Not requested]


11. Confidentiality Top
11.1. Confidentiality - policy

[Not requested]

11.2. Confidentiality - data treatment

[Not requested]


12. Comment Top

-


Related metadata Top


Annexes Top