Singapore (1)
Title of the survey
Survey of Occupational Wages
Organization responsible
The Central Provident Fund Board is responsible for planning and
conducting the survey on behalf of the Ministry of Labour, which
publishes the results.
Periodicity of the survey
Annual.
Objectives of the survey
To obtain wages statistics of major occupations. The major users of
the results are private sector companies, researchers and
students.
Main labour topics covered by the survey
Earnings and wage rates.
Reference period
Wage rates: an hour, a day or a month (in June).
Earnings: the whole month of June.
Coverage of the survey
Geographical
The whole country.
Industrial
All branches of economic activity in the private sector. Excluded
are the public sector (civil service, armed forces, etc.)
and household services.
Establishments
Private sector establishments with at least 25 employees.
Persons
Employees contributing to the Central Provident Fund (CPF). Excluded
are foreign workers on the Levy Scheme for whom the employers have to
pay levy, as well as working proprietors, working directors and unpaid
family workers.
Occupations
All occupations are covered, except domestic helpers and cleaners
working in private households. The actual occupations reported on
depend on the particular employees covered by the survey (see
Sample design).
Concepts and definitions
Employment
Data refer to employees who are CPF contributors, i.e.
persons who paid contributions to the CPF for the reference month. They
include full- and part-time employees; temporary employees;
apprentices, trainees and workers on probation; piece workers and
commission agents; employees temporarily present on payroll during
notice period preceding retirement, resignation or dismissal; as well
as employees temporarily absent from work because of paid or unpaid
vacation, sickness or accident, temporary or indefinite lay off,
industrial dispute, or any other reasons, whether authorized or not.
Excluded are home workers and casual employees; employees from
temporary work agencies and those sub-contracted from other companies or
firms; and seasonal workers.
Data on employees are collected by mode of payment (hourly, daily,
monthly, piece-rated, commission and others). Piece-rated
employees are those who were paid a fixed basic wage plus
piece-rate remuneration. Employees on commission are those who
were paid a fixed basic wage plus commissions.
Data are collected separately for the following five categories:
full-time employees, part-time employees, apprentices and trainees,
temporary employees, and those who worked partly or not at all during
the reference month.
Earnings
Data are collected on monthly gross earnings (called gross
wages in national publications), i.e. the total remuneration received
by an employee for the reference month, before deduction of the
employee's contributions to the CPF or for lateness at work, equipment
spoilage, personal income tax or other deductions.
Included in earnings are basic wage, overtime payments, commissions,
allowances (e.g. shift, food, housing and transport), service points and
other regular cash payments for time worked or work done, as well as
remuneration for time not worked (annual leave or vacation and public
holidays).
Excluded are productivity or incentive bonuses, other bonuses, lump sum
payments and payments in kind, as well as payroll tax, skill development
fund levy, and employers' contributions to the CPF.
Wage/salary rates
Data are collected on two types of wage rates: basic wage
and commencing basic wage.
The basic wage refers to the amount paid to an employee for either a
full hour's, a full day's or a full month's work, before deductions for
the employee's CPF contributions and personal income tax, even though
the employee may not have worked for a full hour, a full day or a full
month. It includes service points (for employees in the hotel and
catering business), but excludes overtime payments, commissions, annual
wage supplement, variable payments or bonuses, shift, food, housing and
transport allowances, other monetary payments and payments in kind.
The commencing basic wage refers to the current minimum or the lowest
basic wage (as defined above) that the company pays or would pay to a
new employee entering the job market without any prior relevant working
experience. Commencing basic wages are not collected for apprentices
and trainees.
Earnings and wage rates data are collected separately for the categories
of employees mentioned above (under Employment); however,
published occupational wage data are based on full-time employees only,
in order to provide a more meaningful basis for wage comparisons across
occupations.
Employment and wage data are not collected by sex or age of employees.
However, wage data by sex and age group are obtained by matching the
survey data with the administrative records held in the Central
Provident Fund Board data base.
Hours of work
Not relevant.
International recommendations
The definition of earnings conforms to the international
recommendations, in that it refers to cash payments made on a regular
basis, for time worked or work done, including remuneration for time not
worked and paid for, and excluding irregularly paid bonuses and
gratuities in cash. However, payments in kind are excluded.
The definition of the basic wage conforms to the definition of the basic
wage rate recommended in the international standards.
Classifications
Industrial
Employees are allocated to the activity code of the establishment in
which they are employed, and data on earnings and wage rates are
classified by major industry division, according to the Singapore
Standard Industrial Classification (SSIC), 1990, which conforms to the
basic framework of the International Standard Industrial Classification
of all economic activities (ISIC), Rev. 2, 1968.
Occupational
Employees are classified by occupation on the basis of the detailed job
title given by the employer. Data on earnings and wage rates are coded
to the five-digit level of the Singapore Standard Occupational
Classification (SSOC), 1990, which is adapted from the International
Standard Classification of Occupations (ISCO-88). About 300
individual occupations are covered.
Others
Earnings and wage rate data are classified by sex and age group
on the basis of information in the CPF administrative records.
Sample size and design
Statistical unit
The sampling unit is the firm (establishment, company or
organization).
The unit of observation is the individual employee who is a
CPF contributor.
Survey universe / sample frame
This is the list of firms and establishments generated by the Central
Provident Fund Board (i.e. the government agency in charge of social
security contributions). The sample is selected from a list of
approximately 7,000 private sector establishments with at least 25 paid
employees. The frame is updated annually on the basis of employers'
records maintained by the CPFB.
Sample design
The survey is based on a random sample of about 2,000 establishments,
stratified by industry group and employment size, using a sampling
fraction of 1/3. Data are then collected on each individual CPF
contributor within each selected establishment. The survey covers
approximately 200,000 CPF contributors. The sample is renewed each
year.
Field work
Data collection
This takes place during the three- to four-month period following the
reference month. The survey is conducted through mailed questionnaires
and the information obtained from employers. Some large organizations
supply the information on computer listing or magnetic tapes.
Where necessary, clarifications are sought through telephone calls with
the employers.
Survey questionnaire
This consists of three parts:
- Part A relates to the business activity (name and address of the
firm, establishment or company, and description of main and other
activities of each office (head office and branches) of the company).
- Part B is designed to obtain occupational wage data for individual
CPF contributors and employers are required to provide the following
information for each employee:
- name and CPF account number,
- detailed title of the occupation,
- mode of payment,
- commencing basic wage,
- basic wage,
- gross earnings paid for the reference month,
- office (as shown in Part A) where the employee is attached,
- category of employee (full-time, part-time, temporary,
apprentice or trainee, piece-rated or other employees who worked
partly or not at all during the reference month).
- Part C relates to employees who are not CPF contributors, but who
are under the foreign workers levy scheme.
In Part B, information on occupation and mode of payment is preprinted
on the basis of data available with the CPFB. Employers are required to
verify and update the information, and to complete it for the remaining
items in the questionnaire. Detailed instructions on inclusions and
exclusions are provided with the questionnaire.
Substitution of sampling units
If selected establishments have ceased operation, changed address,
refused to respond or employ no employees during the reference month,
they are replaced by other establishments selected from the sample
frame.
Data processing and editing
Data are processed by computer; coding and editing is carried out both
manually and electronically. In the case of missing or inconsistent
data, respondents are contacted by telephone and mail.
Types of estimates
Average monthly commencing basic wages, monthly basic wages and monthly
gross earnings of selected occupations by sex, as well as means, medians
and quartiles by industry and age group.
Monthly wage data of both full-time and part-time CPF contributors
are provided by employers. Wages for daily and hourly rated employees
are converted to their monthly equivalent to derive the final monthly
estimates.
Construction of indices
None.
Weighting of sample results
The survey results are not grossed-up. They are considered to be
representative of occupational data in establishments with 25 or more
employees.
Adjustments
Non-response
None.
Other bias
None.
Use of benchmark data
Not relevant.
Seasonal variations
Not relevant.
Indicators of reliability of the estimates
Coverage of the sampling frame
The coverage of private sector establishments with 25 or more
employees is complete.
Sampling error / sampling variance
Not calculated.
Non-response rate
In the 1992 survey, the non-response rate was seven per cent in terms of
establishments, and two per cent in terms of employees.
Non-sampling errors
The main source of error may consists in the erroneous coding of a
detailed occupation at the five-digit level: occupational wage data are
classified on the basis of job titles provided by employers; considering
the number of employees covered, the extent to which job titles and
descriptions can be verified with these employers is limited.
The following remarks should also be noted when using the survey
estimates:
- The scope and job responsibilities of employees classified under the
same occupation may vary widely across firms; hence, the wages of
certain occupations such as managing director, may vary according to the
job responsibility, experience and size of firm.
- In certain occupations (such as lawyers and accounts) in which
bonuses and profit-sharing payments represent a large component of
earnings, the earnings data that are collected may be significantly
lower than the actual earnings, since these types of payment are
excluded from the concept used.
- Age is used as a proxy for experience of employees. In general,
employees in the older age groups tend to earn more than those in the
younger age groups. However, in some instances, older employees may
earn less than younger ones in the same occupation, due to factors such
as the differences in scope of work, job responsibility and educational
qualifications.
Conformity with other sources
Not relevant.
Available series
Published tables include detailed listings of average, mean, median and
quartiles of monthly commencing basic wages, basic wages and gross
earnings of selected occupations, by sex, industry and age group.
History of the survey
The Survey on Occupational Wages started in 1985. Until 1990, it
consisted in a census of all establishments in the public and private
sectors, with 25 or more CPF contributors. Since 1991, it is conducted
on a sample basis and covers establishments in the private sector only,
with at least 25 paid employees.
The reference period referred to the month of August for the years
1985 to 1991; since 1992, it refers to the month of June.
Prior to 1991, occupations and industries were classified according to
the Singapore Standard Occupational Classification, 1978, and the
Singapore Standard Industrial Classification, 1978, respectively.
Documentation
Ministry of Labour: Report on Wages in Singapore (annual,
Singapore); published about a year after the survey reference
period and includes methodological information on the survey.
Confidentiality / Reliability criteria
The survey is conducted under the Statistics Act (Chapter 317),
Revised Edition 1991, and under Section 55 of the Central Provident
Fund Act which empowers the Board to collect and compile statistics
relating to employers and employees. The information provided by
employers is strictly confidential and used for statistical purposes
only. No particulars or information relating to any individual
person or establishment is published or released to the public.
Other information
Data supplied to the ILO for publication
Data on average monthly basic wage rates by occupation and industry
group and by sex, obtained from the Occupational Wages Survey, are
published each year in Statistics on occupational wages and hours of
work and on food prices - October Inquiry results, a special
supplement to the ILO Bulletin of Labour Statistics.
Other sources of wages statistics:
The Survey on Annual Wage Changes:
The information on wage rates and earnings obtained from the
Occupational Wages Survey is complemented each year by another survey
conducted by the Research and Statistics Department of the Ministry of
Labour: the Survey on Annual Wage Changes This survey is
conducted by mail questionnaires and covers only the private sector.
All unionized companies with 10 or more employees are surveyed. For the
non-unionized sector, the survey covers all companies with 100 and more
employees, and a representative sample, stratified by industry, is drawn
of companies with 10 to 99 employees. In 1992, a total of 1,167
unionized and 3,442 non-unionized companies were surveyed, which
represented a total of 308,700 bargainable employees who were in
continuous employment for at least a year (i.e. employees who are
eligible to join unions, whether or not they have done so). The survey
reference period covers a whole year (from November of a given year to
December of the following year).
This survey obtains data on the following components of wages: basic
wage, annual wage supplement and variable payments and bonuses. The
basic wage increase in the year is segregated into two components:
annual increments (i.e. service and merit increments) and wage
adjustments in response to labour market conditions. Data are also
collected on the adoption of the flexible wage system, which comprises a
basic wage and a variable payment linked to company or individual
performance.
The final survey results take into account weighting factors based on
the reciprocal of the sampling fractions. Data on annual wage changes
are weighted by the number of bargainable employees.
The results of the Survey on Annual Wage Changes are also published in
Report on Wages in Singapore (see above, under
Documentation).
Records of the CPF Board: Average monthly earnings data are
also compiled from administrative records maintained by the CPF Board.
The data cover all CPF contributors in the public and private
sectors and are compiled by estimating the total remuneration from
all employees' CPF contributions. Gross earnings data
include basic wages and other regular payments like
shift allowances, overtime payments, bonuses, incentive payments and
other monetary allowances, prior to employees' deductions for CPF
contributions. They exclude employers' CPF contributions.
The estimated total remuneration of all CPF contributors in a month is
then divided by the total number of CPF contributors in that month to
obtain the average monthly earnings of the month. The average monthly
earnings for the year is the simple average of the average monthly data
over twelve months. The data series are available by industry only, and
not by occupation, as the administrative records of the CPF Board do not
capture employees' job titles.
For publication of the average monthly earnings series, see:
Ministry of Labour, Research and Statistics Department: Singapore
Yearbook of Labour Statistics (annual, Singapore).
Statistics of average monthly earnings derived from the administrative
records of the CPF Board are transmitted to the ILO for publication in
the Year Book of Labour Statistics. They appear in Tables 16,
17A, 17B, 19 and 20 of that publication.
Statistics of average monthly earnings in Electricity, gas and water,
Trades, restaurants and hotels, Financing, insurance, real estate and
business services, and Community, social and personal services, are also
stored in the ILO data base and are available on request.