Spain (2)

Title of the survey

Encuesta de Coyuntura Laboral (ECL) (Survey of Economic Trends).

Organization responsible

Ministerio de Trabajo y Seguridad Social, Dirección General de Informática y Estadística, Subdirección General de Estadística.

Periodicity of the survey

Quarterly, on a continuous basis.

Objectives of the survey

To obtain information on employment and its composition, mobility of labour and the reasons for it, the working day, absence from work and the reasons for it, certain aspects of labour relations and the opinions of employers with regard to the development of the labour market.

Main labour topics covered by the survey

Employment, the working day and the opinion of employers.

Reference period

For employment: the last day of the reference quarter. For data on the working day: the whole of the reference quarter. The opinions of employers refer to the following quarter or to the corresponding quarter of the year following that of the reference quarter.

Coverage of the survey

Geographical

The whole national territory, with the exception of Ceuta and Melilla.

Industrial

Non-agricultural activities covering all branches of activity in industry, construction, services, except for public administration, national defence and social security, diplomatic representation, international organizations and religious organizations.

Establishments

Establishments with six or more workers, which are centres of contribution to social security.

Persons

All employees who carry out their activities in these centres.

Occupations

Not relevant.

Concepts and definitions

Employment

Employees are defined ned as those persons who, on the last day of the quarter to which the survey refers, have an employment relationship with an enterprise located in Spanish territory in which their work is performed. They include workers who, on the last day of the quarter, are not carrying out their work because of vacation, leave, labour dispute etc., workers laid off because of a temporary shortage of work, and workers who are suspended or on short time as the result of short-time working. The following groups are excluded: Employees are divided into: For each of the categories of employees, data are collected by sex.

Earnings

Not relevant.

Wage/salary rates

Not relevant.

Hours of work

Data are collected on the actual working day; this is the average number of hours actually worked by the worker during the quarter. Data are collected separately for full-time and part-time workers on the following three topics:

International recommendations

The concept and definition of the actual working day employed in this survey comply with the current international standards regarding statistics on hours actually worked. However, the actual working day is estimated by the quarter rather than by the week or the month.

Classifications

Industrial

The 1974 Clasificación Nacional de las Actividades Económicas (CNAE) is used, with coding at the two-digit level. The results are published out by branch of economic activity, division of economic activity and groupings of branches of economic activity. The CNAE is compatible with the International Standard Industrial Classification of all economic activities (ISIC), Rev. 2, 1968 at the division level (two-digits).

Occupational

Not relevant.

Others

The data are classified by size of centre (in three groups according to size; six to 50 workers; 51 to 250 and over 250 workers) and autonomous community.

Sample size and design

Statistical unit

The sampling units are the centres included in the survey coverage, which appear in the social security records. The unit is the contribution account which is at the same time the basic unit of the records. This unit is composed of a group of workers of one enterprise who are homogeneous in respect of their contributions and whose activity is carried out in one province. This group of workers is associated the employers' registration number with social security. Although in theory the establishment or centre of work and the contribution account are not the same, in practice they coincide in a large percentage of cases.

Survey universe / sample frame

The survey frame is the directory of enterprises obtained from the file of accounts of contributions to social security. This directory includes the units which fall within the survey coverage (contribution centres with five or more workers). The file of accounts of contributions is the only directory available which supplies continually updated information on employment, from the point of view of the enterprises.

Sample design

Stratified sampling is carried out according to size of contribution centre and autonomous community. The autonomous communities are regarded as independent populations and in each of them stratification has been carried out on the basis of the number of workers in the centres. For this, the following sizes are used: 6 to 10 workers; 11 to 25; 26 to 50; 51 to 100; 101 to 250; 251 to 500; and more than 500 workers. The size of the sample is approximately 10,000 units. All centres with more than 500 workers are included; they are about 1,000 of these centres each quarter. The distribution of the remaining sample units in those strata which are not covered exhaustively, some 9,000 in number, was carried out once during the first quarter of the survey. No changes in these sample sizes are envisaged in principle, unless marked changes are found in the distribution by strata or in the other variables in the records. In a first phase, the 9000 units were distributed among the various autonomous communities and subsequently within each of them according to the size of the centres. Distribution within the separate autonomous communities was carried out on the basis of various criteria. The first was to ensure a minimum of 250 units in each one. The remaining units were assigned to the separate autonomous communities according to the number of centres and the variation in the number of workers per centre. Finally, when the number of units in each community was fixed, it was distributed by size groups of centres in proportion to the number of workers in each, with a minimum of eight units guaranteed in all cases where this was possible. The sample sizes lead to an overall sampling fraction of 0.042, with different sampling fractions for each stratum. The sample was selected using systematic sampling with a random starting point within each cell comprising the autonomous community and a size group of centres. The population units of each of these strata were listed in advance according to the code of economic activity registered in the social security record. The sample used each quarter comprises the sampling units of the previous quarter, with units added or removed, as necessary, following their treatment based on the different types of situation, both within the sample and external to it (see below under Substitution of sampling units). When all the reasons for irregularity are taken into account, about eight per cent of the sample is updated each quarter, which in annual terms is equivalent to approximately a quarter of the sample.

Field work

Data collection

The questionnaires are sent by post to the sample centres during the last two weeks of the quarter to which the data refer. The sample units are surveyed using a mixed system: by an interviewer for one part of the sample and, for the other enterprises in the survey, with the enterprise filling the questionnaire plus supplementary telephone calls made by specialist statistical staff. The second method is applied to approximately one-third of the sample.

Survey questionnaire

The questionnaire comprises the following main sections: Instructions are sent with the questionnaire and an instruction manual is available for interviewers.

Substitution of sampling units

Units which cease to be part of the frame through having reduced their workforce, according to the information in the record, or with fewer than six workers, or through changing their economic activity and taking up one which is not included in the survey coverage, are replaced by units with similar characteristics with respect to their location, size of the centre and economic activity. The first of these leads to a turnover of 2.5 per cent of the sample every quarter with respect to the previous quarter. The second of these is so rare as to be negligible in practice. Substitutions of sampling units are also made when units cannot be located, when they explicitly refuse to collaborate for various reasons, when they have ceased operations or in the case of centres which engage in activities not covered by the survey. The irregularities which occur every quarter for the reasons above involve about three per cent of the sample. In this case, if time permits, substitution is carried out in the same quarter in which the irregularity is observed, using groups of reserve units with similar characteristics. This occurs in about 60 per cent of cases. On the other hand, there are centres which do not openly refuse to collaborate in the survey, but whose questionnaires cannot be obtained in time. These make up about six per cent of the sample. In this case, substitution is not automatic and is used only when it is discovered that a unit has shown this pattern for several quarters in succession. Finally, in the case of centres where there is a temporary stoppage of activity, there is no substitution, but the centre remains in the sample so that it can be surveyed during its periods of activity.

Data processing and editing

Every quarter when the field work is completed, the questionnaires are received together with the irregularities arising in the field (refusals to collaborate, inability to locate, layoffs, etc.). The questionnaires are checked in order to detect possible errors. Checking is carried out basically in three separate ways: checking of individual questionnaires for invalid or inconsistent values and anomalous ratios among the variables; checking for inconsistencies between data supplied by the centre for the reference quarter and data from previous quarters; analysis of the behaviour of certain variables, examining their development and distribution by the variables of the classification and making comparisons with other statistical sources. When this has been carried out, the file of questionnaires is submitted to a number of processes in which the coverage is assessed and the grossing-up factors, etc. are assigned, until it is ready for producing the results.

Types of estimates

The estimates calculated refer to quarterly averages of working days, hours not worked and overtime. The average working day per quarter per worker is estimated as the average number of hours actually worked per quarter and per worker. It is obtained as the weighted average of the average days worked per full- and part-time worker. The average working day per quarter per full-time worker is estimated as follows: first, the total number of hours is calculated, in theory as the hours all full-time workers in the centre were intended to work during the quarter. For this, the annual hours agreed upon, the hours corresponding to public holidays and those granted as vacation and long weekends which need not be made up are added together. The sum is then multiplied by the number of full-time workers in the centre during the reference quarter, and the product is divided by four, so as to obtain a quarterly average. Hours of overtime worked during the quarter are added to this average and the hours not worked for reasons stated above are subtracted (in both cases with reference to the total number of full-time workers). The result is divided by the number of full-time workers. The average working day per part-time worker is obtained by subtracting from the number of hours which all part-time workers in the centre were intended to work during the reference quarter the hours not worked for the reasons referred to above. The result is divided by the total number of part-time workers in the centre.

Construction of indices

Not relevant.

Weighting of sample results

Expansion factors are used for stratified sample, corrected for non-response. For calculating the average of variable Y with respect to another variable X, such as the average working day per worker, the ratio estimate is used, i.e. the ratio of the expansion factors of Y and X.

Adjustments

Non-response

Non-response is taken into account in the expansion factors for the sample.

Other bias

None.

Use of benchmark data

Not relevant.

Seasonal variations

Not relevant.

Indicators of reliability of the estimates

Coverage of the sampling frame

This is considered that the record of contribution accounts to social security covers about 85 per cent of total employment.

Sampling error / sampling variance

The sampling error of the total of a variable X is calculated using the standard deviation of the variable. The sampling error is measured in absolute terms and as a percentage (relative sampling error).

Non-response rate

The quarterly response rate for enterprises is around 85 per cent, and the final coverage rate amounts to 90 per cent, owing to substitutions.

Non-sampling errors

Not relevant.

Conformity with other sources

Not relevant.

Available series

History of the survey

The ECL began in the second quarter of 1990 as a quarterly survey.

Documentation

Ministerio de Trabajo y Seguridad Social, Dirección General de Informática y Estadísticas, Subdirección General de Estadística: Encuesta de Coyuntura Laboral (Madrid; quarterly). This publication contains the definitions of the various concepts used and the methodology applied. Time series with data on the main variables are also included in: idem: Boletín de Estadísticas Laborales (ibid., monthly). idem: Anuario de Estadísticas Laborales (ibid., annual). The survey data are also available on diskette.

Confidentiality / Reliability criteria

The data collected are protected by statistical confidentiality as laid down in law 12/89 on statistics of 9.5.89. Information on classifications with high sampling errors, or whose characteristics would enable responding units to be identified, is not made public.

Other information

Data supplied to the ILO for publication

Quarterly data on paid employment from this survey will shortly be published in the Bulletin of Labour Statistics.