Colombia (1)
Title of the survey
Muestra Mensual Manufacturera (Monthly Sample in Manufacturing).
Organization responsible
Departamento Administrativo Nacional de Estadística (DANE).
Periodicity of the survey
Monthly.
Objectives of the survey
To provide indicators and changes in employment, wages and salaries,
hours worked, production and sales.
Main labour topics covered by the survey
Employment, wages and salaries (earnings), hours worked and production.
Reference period
For employment: the month.
For earnings and hours worked: the pay period (the month or the week).
Coverage of the survey
Geographical
The whole country.
Industrial
Manufacturing.
Establishments
Establishments with ten or more workers.
Persons
All employees.
Occupations
Not relevant.
Concepts and definitions
Employment
Employees refer to persons who perform paid work in
the establishment during the reference period.
Workers on
unpaid leave, on military service, pensioners and members of the
board of directors of the enterprises who are paid exclusively
for their attendance at meetings, who render
occasional services to the establishment and whose remuneration
is a fee, are excluded. Home workers are also excluded.
A distinction is made between:
- permanent workers: all workers under contract
for an unlimited period, even if such
persons are temporarily absent from work because of vacation,
strike, sickness or maternity leave or absence
from work with pay;
- temporary workers: the
average number of persons under contract for a fixed period, who
have worked in the establishment, whether they were contracted
directly by the establishment on conditions such as work by the
day, piece work, for a particular job etc., or whether their
contract was concluded via enterprises which specialize in
supplying workers. They also include apprentices in
administrative work or in production;
and within each category, between:
- managers and non-manual workers: persons engaged in
management, administration, technical or office work within
the establishment, who are not directly concerned in production;
and
- manual workers and operatives: persons whose activity is
directly related to production or related tasks.
Earnings
Wages and salaries mean the fixed or ordinary remuneration
paid to workers for services rendered during the reference period,
before deduction of sums to be withheld at source,
for social security, trade union dues, the employees' fund, etc.
The following are included: basic wages and salaries, extra pay and
permanent monthly allowances (for rises in the cost of living,
working conditions, risks etc.); travel expenses; payment to
piece workers or production bonuses, payment for overtime or work on
obligatory days of rest, at night or on holidays; sickness or
maternity leave paid for directly by the employer, commissions or
bonuses on sales and increased production and travel
allowances where these are constant.
Wages and salaries include only those amounts on the basis of which
social benefits are paid.
Information is also collected separately regarding social
benefits arising during the reference period, i.e. obligatory,
special, agreed-upon payments other than wages or salaries made by the
employer to the workers employed. These include: the employer's
contribution to social security and to the various compensation funds,
statutory and non-statutory bonuses, vacations, separation pay when this
arises, interest on retirement or redundancy pay (cesantias) and other
grants to employees, if and when these are a component of the wage or
salary.
Retirement pensions paid to retired persons, the value of fees arising
from professional services, the value of contracts with persons who
carry out industrial work for the establishment in their private houses,
benefits paid out, medical and funeral expenses, life assurance, housing
subsidies, study grants and other occasional bonuses are excluded.
For permanent manual and non-manual employees, wages, salaries and
benefits are considered separately. The earnings obtained (wages +
salaries + benefits) are calculated together. For temporary manual and
non-manual employees, only earnings are calculated.
Wage/salary rates
Not relevant.
Hours of work
Information is collected on the total number of hours worked,
for wage earners, separately for permanent and temporary
workers. The time corresponding to paid leave, vacations, absences by
reason of sickness, Sundays and holidays not worked is excluded.
Hours worked are classified as:
- normal hours: these cover only the hours worked during the normal
working day by manual workers and operatives;
- overtime hours: these cover both the hours worked outside the
normal working day and those worked on obligatory days of rest by manual
workers and operatives.
Hours worked by directors and non-manual employees are not collected.
International recommendations
The definitions of wages and salaries and of hours actually worked
comply with the international standards in force regarding statistics of
earnings and hours of work from current surveys (monthly or quarterly).
Classifications
Industrial
The International Standard Industrial Classification of all economic
activities (ISIC), Rev. 2, 1968 is used at the industry group level
(three-digit level).
Occupational
Not relevant.
Others
Data are classified according to category (salaried employees or wage
earners). Results are also obtained at the national level and by
regions of greatest development in production (Bogotá, Antioquia and
Valle del Cauca).
Data on employment are classified by size of establishment.
Sample size and design
Statistical unit
The unit supplying the data is the industrial establishment
with ten or more workers. It is defined as the combination of
activities and resources which, in the form of a single legal entity,
forms a unit of ownership or administration, for the production of a
class, as homogeneous as possible, of manufactured goods at one single
location, and from which independent accounting records are received
regarding materials, the labour force and other physical resources which
are used in the process of production and in complementary or auxiliary
activities.
Survey universe / sample frame
Since 1991 the reference point has been the 1985 Annual Survey of
Manufacturing (1985). It has been supplemented by updated information
supplied by each of the regional directorates of DANE regarding changes
in and the existence of establishments.
Sample design
The sample covers a total of 875 establishments selected at national
level and distributed as follows:
- 392 establishments, whose inclusion was regarded as necessary by
reason of their importance with regard to levels of production and
employment. These establishments guarantee in advance a minimum
coverage of 50 per cent of the gross production of each industry group,
60 per cent of the total production in manufacturing and 45 per cent of
total employment;
- 483 establishments earmarked for random inclusion. Here a
stratified method of sampling with systematic selection was adopted.
Stratification was carried out in two phases: (i) each of the industry
groups was defined as a stratum, giving 28 strata in all; (ii) each
stratum was subdivided into substrata in accordance with the observed
distribution, within each industrial grouping, of employment and gross
production.
The sample size for each substratum is estimated in such a way that all
groups satisfy a 95 per cent confidence interval with a maximum relative
error of 10 per cent for statistics of average output. Systematic
selection within each substratum was used, with a probability
proportional to the size of the establishments (in terms of employment
and gross production).
The sample is updated only when the frame is renewed.
Field work
Data collection
Questionnaires are sent by post every month to the sample establishments
and returned (also by post) to the six regional directorates of DANE.
Before the questionnaires are distributed to the regional directorates,
the identification of establishments and the month to which the
information refers are printed on them.
Survey questionnaire
A simple form is used, of one page, containing the data identifying the
establishment and the variables which the unit should provide (workers
employed according to occupational categories and type of relationship,
total of wages and salaries and social benefits paid, total hours
worked, total value of production and total value of sales).
The establishments also receive a manual describing the type of
information sought for the Monthly Sample of Manufacturing, with general
information regarding the survey and specific instructions and
definitions.
Substitution of sampling units
Not relevant.
Data processing and editing
As soon as the forms are received at the regional headquarters, in the
municipal offices or through a DANE collector, a general check of the
forms is carried out on the basis of a control card for each
establishment in which all the monthly information is recorded.
Inquiries are also made by telephone and personal visit where data are
lacking or inconsistent. As soon as the information has been verified
and its coverage checked, it is transferred to magnetic tape and copied
on to two more tapes for verification. One of these is used in
processing the information and the other is held as a back-up copy.
Programmes for detecting inconsistencies are used to validate numerical
fields, and records for each establishment permit the detection of
errors in the information and variations outside the range. Various
corrections and revisions of the data are carried out and the expanded
results of the variables surveyed are produced and revised.
Types of estimates
- Totals of employment, wages and salaries, social benefits paid and
hours actually worked per month.
The average number of persons employed temporarily is calculated, taking
into account the total number of days (worked or not) paid for
during the period over the number of calendar days making up that
period.
- Indices and changes in the persons employed, wages and salaries and
hours worked.
Construction of indices
Index number of persons employed, wages and salaries and hours worked
are constructed, according to occupational category, type of
relationship and industry groups.
An index of real wages and salaries is also constructed, using the
Consumer Price Index calculated by DANE for medium (non-manual
employees) and low (manual employees) incomes.
Weighting of sample results
Estimates of totals:
- at the group or stratum level, for any of the following variables:
number of non-manual employees, number of manual employees, wages and
salaries, and hours actually worked; the estimated value of the
variable is obtained by multiplying the estimated value for the
establishments included in the sample by the reciprocal of its
probability of selection for the sample; these are then added to the
data for the establishments completely enumerated.
In estimating wages of manual employees and salaries of non-manual
employees, the sampling fractions corresponding to the number of manual
workers and of salaried employees respectively are used.
- at the level of total manufacturing, the estimated totals, for each
of the variables surveyed are obtained by adding together the estimates
of all the 28 strata or industry groups.
Estimates of averages:
Nominal and real average wages and salaries are estimated for non-manual
employees, manual employees and all employees together, and average
nominal wage per hour worked by manual employees, on the basis of the
estimated data of the respective variables by industry group and for
total manufacturing.
Adjustments
Non-response
Adjustments are made, but the methodology is not available.
Other bias
None.
Use of benchmark data
In the method of calculating the estimates, data on employment,
production and wages and salaries for the last months for which
information is available are used.
Seasonal variations
Not relevant.
Indicators of reliability of the estimates
Coverage of the sampling frame
Not available.
Sampling error / sampling variance
Not available.
Non-response rate
Not available.
Non-sampling errors
Not available.
Conformity with other sources
Not relevant.
Available series
- indices of and changes in persons employed, national total and
totals for the three regions of the country: total according to
occupational category and type of relationship;
- indices of and changes in wages and salaries, national total and
totals for the three regions of the country: nominal and real averages,
according to occupational category, type of relationship and industry
group;
- indices of and changes in hours worked, national total and totals
for the three regions of the country: totals according to category
(normal and overtime) and industry group.
History of the survey
The Monthly Sample in Manufacturing began in May 1962, with the aim of
producing indicators of employment and wages and salaries. Over the
years the survey frame and the sample have been modified.
In July 1970, the Annual Survey of Manufacturing of 1968 was taken as
the reference point. With this sample as the basis, results of
production, employment and wages salaries were presented, the last two
by occupational category, for the whole industry and for the 20 ISIC
industry groups, until December 1980. In 1978, the sample was updated,
at which time a new sample design was adopted for which results were
obtained as from January 1981.
The present survey has as reference point the Annual Survey of
Manufacturing of 1985 and the new methodology has been applied since
1991. The indicators calculated are classified by occupational
categories and type of relationship. The survey also provides
indicators representative of manufacturing performance in those sections
of the country which have the greatest development in production. The
various indices are calculated on the basis of the 1990 monthly averages
= 100. With the former methodology they were calculated on the basis of
the 1980 monthly averages = 100.
Documentation
Departamento Administrativo Nacional de Estadística (DANE):
Boletín de Estadística (monthly, Bogotá). A summary of the new
methodology was given in No. 459 of June 1991.
The survey data are also available on diskette.
Confidentiality / Reliability criteria
Not available.
Other information
Data supplied to the ILO for publication
The following series are published in the Yearbook of Labour
Statistics:
- index numbers of paid employment (employees) in manufacturing, in
Table 5A;
- index numbers of monthly earnings of employees in manufacturing, in
Table 17A.
In addition, monthly series of index numbers of paid employment and
monthly earnings of employees in manufacturing are published in the
Bulletin of Labour Statistics.