Thailand

1. Title of the survey

Labour Force Survey.

2. Organisation responsible for the survey

National Statistical Office, Office of the Prime Minister.

3. Coverage of the survey

(a) Geographical

(b) Persons covered

1. private households, which include one-person and multi-person households;
2. special households, which include persons living in group-living quarters within the compound of a factory, or in a dormitory or boarding house which is not exclusively for students.

Excluded are: members of the armed forces; institutional populations, i.e. inmates of penal institutions, priests, students living in dormitories, etc.; and households of foreigners working in international organisations. Household members away from home for three months or more are also excluded.

Persons below 11 years of age are not asked questions on economic activity.

4. Periodicity of the survey

Since 1984, the survey is conducted in three rounds, in February, May and August of each year. Prior to that date, it was bi-annual: the first round was from January to March; and the second round from July to September, during the agricultural season.

5. Reference period

The week preceding the enumeration period (known as the survey week).

6. Topics covered by the survey

The survey provides information on employment, unemployment, hours of work, wages and income, duration of unemployment, industry, occupation, status in employment, level of education and usual activity.

7. Concepts and definitions

(a) Employment

1. worked for at least one hour for wages, profits, dividends or any other kind of payment, in cash or in kind; or,
2. did not work at all but had regular jobs, business enterprises or farms from which they were temporarily absent because of illness or injury, vacation or holiday, strike or lock-out, bad weather, off-season or other reasons, such as temporary closure of the workplace, whether or not they were paid by their employers during their period of absence, provided that in the case of a temporary closure of the workplace the expectation was that it would be reopened within 30 days from the date of closure and they would be recalled to their former job; or,
3. worked for at least one hour without pay in business enterprises or on farms owned or operated by household heads or members (unpaid family workers)."

Also included are:

1. full- and part-time workers seeking other work during the reference period;
2. full- and part-time students working full- or part-time;
3. paid apprentices and trainees;
4. persons who performed some work for pay or profit during the reference period, while being subject to compulsory schooling; or retired and receiving a pension; or registered as jobseekers at an employment office or receiving unemployment benefits;
5. private domestic servants;
6. members of producers' co-operatives.

Excluded from the employed and considered as inactive are persons only engaged in own housework; unpaid apprentices and trainees; and persons doing unpaid community or social work.

(b) Underemployment

(c) Unemployment

1. those who have been looking for work during the preceding 30 days;
2. those who have not been looking for work because of illness or belief that no suitable work was available, waiting to take up a new job, waiting for agricultural season or other reasons."

Also included are:

1. full- and part-time students seeking full- or part-time work;
2. participants in employment promotion schemes;
3. unpaid family workers who were temporarily absent from work, if available for work during the survey week.

Availability for work is assessed on the basis of the number of days available for work during the survey week.

Persons aged 11 years and over who, during the survey week, were neither employed nor unemployed as defined above, but were waiting for the appropriate season, being persons who usually worked without pay on farms, or in business enterprises engaged in seasonal activities owned or operated by the head of the household or any other member of the household, are considered as "seasonally inactive labour force", distinct from the "current labour force" and added to the latter to make up what is described as the "total labour force".

Persons not in the labour force are those who were neither employed nor unemployed during the survey week, nor classified as seasonally inactive labour force as defined above. They include:

1. persons who, during the survey week, were under 11 years of age;
2. persons who were 11 years of age and over but were neither employed nor available for employment because they were: engaged in household works or in studies; two young (below 15 years of age) or too old (above 60 years of age); incapable of work because of physical or mental disability or chronic illness; voluntarily idle; working without pay, profits, dividends or other payments for persons who were not members of the same household; working without pay, profits, dividends or any other payments for charitable organisations and institutions; otherwise not available for employment.

(d) Hours of work

(e) Informal sector

(f) Usual activity

8. Classifications used

Employed persons and unemployed persons with previous work experience are classified by industry, occupation and status in employment. All persons aged 11 years and over are classified by level of education.

(a) Industry

If a person has more than one job, the industry corresponding to the recorded occupation is asked for.

(b) Occupation

For a person having more than one job, only the job at which he/she worked for the greater number of hours during the survey week is recorded. If the number of working hours for each job is exactly the same, the job which gives him/her the higher income is recorded. If the number of working hours and the income earned from each job are the same, the job for which the person has preference is recorded. If the respondent cannot give his preference, the job at which he/she has been working for the longest time is the one recorded.

(c) Status in employment

1. Employer,
2. Government employee (including civil servants, police, municipal officers and employees of government enterprises),
3. Private employee,
4. Own-account worker,
5. Unpaid family worker.

(d) Level of education/qualifications

1. No formal education,
2. Less than Pratom 4,
3. Lower elementary,
4. Upper elementary,
5. Lower secondary,
6. Upper secondary,
7. College or University,
8. Teacher training,
9. Technical vocational,
10. Short course vocational,
11. Other.

9. Sample size and design

(a) The sample frame

(b) The sample

Groups of provinces in each region and Bangkok Metropolis constitute strata and each province is a substratum. There are altogether five strata, i.e. North, North-East, Central, South and Bangkok Metropolis, and 73 substrata.

Each province or substratum is divided into three parts according to the type of local administration, namely municipal areas, sanitary districts and non-municipal areas outside sanitary districts. The sample selection of blocks and villages is performed separately and independently in each part as follows:

1. In municipal areas, a number of sample blocks are selected systematically from each province, with a sample size proportional to the total number of blocks in each province. For the May 1987 round, the total sample blocks was 420 blocks out of 6,630 blocks for Bangkok Metropolis and 455 blocks out of 6,172 blocks for other provinces.
2. In sanitary districts, a number of sample villages are selected systematically from each province. The sample size is proportional to the total number of villages in all sanitary districts in each province. For each survey round, the total sample villages is about 550 out of 4,507 villages.
3. In non-municipal areas and outside sanitary districts, a number of sample villages are selected systematically from each province. The sample size is also proportional to the total number of villages in non-municipal areas and outside sanitary districts in each province. For each survey round, the total number of sample villages is 1,085 villages out of 52,999 villages.

Households are the ultimate sampling units. For each round of the survey a new listing of households is made for every sample block and village to serve as the sampling frame. A systematic sample of 9 households is selected from each of the sample blocks and villages in sanitary districts, while 6 households are selected from each of the sample villages in non-municipal areas and outside sanitary districts. All special households located within the sample areas, totalling around 220, are included in the sample and the persons in the household are systematically selected for interview.

For the February 1988 survey round, the sampling fractions were 7 to 8 per cent in municipal areas, and 2 to 3 per cent in non-municipal areas, representing altogether some 20,000 households, i.e. 135,000 persons.

The whole sample is distributed into two sub-samples: one for survey rounds Nos. 1 and 3 (February and August), the other for round No. 2 (May). Each year the sample is renewed on the basis of a pilot survey conducted around October to construct the frame to be used for the survey the following year, and the sub-samples are selected independently.

(c) Rotation

10. Field work

(a) Data collection

A long questionnaire covering household characteristics, migration, education, work characteristics and income is used for enumerating individuals in the first and third rounds of the survey, while the second round survey using a short questionnaire covers only household characteristics, education and work characteristics.

(b) Substitution of ultimate sampling units

PSUs (villages) which cannot be reached or where there is total non response are replaced by other villages with similar characteristics and located nearby.

11. Quality controls

Enumerators' work is checked by supervisors for correctness of replies and coding. During the processing stage, manual editing and a 100 per cent verification of data entry and machine editing are carried out.

12. Weighting the sample

Survey estimates are adjusted by ratio estimation to population levels using independant estimates, namely the "Population Projections for Thailand, Whole Kingdom and Regions 1980-2015". The variables used in the post-stratification are age/sex group, block/village, area, and region.

13. Sampling errors

14. Adjustments

(a) Population not covered

(b) Under/overcoverage

(c) Non-response

15. Seasonal adjustment

No adjustment is made for seasonal variations.

16. Non-sampling errors

Not available.

17. History of the survey

The Labour Force Survey has been carried out by the National Statistical Office since 1963. Beginning 1971, two rounds of the survey for the whole kingdom have been conducted each year, the first round enumeration during the January-March period, coinciding with the non-agricultural season and the second round during the July-September period, coinciding with the agricultural season. Commencing with the year 1984, another round of the survey has been conducted each year, the first round being in February, and the second and third rounds in May and August respectively.

Effective from the first round of 1983, certain conceptual and definitional changes have been introduced. Major changes are as follows:

1. Some measurements of the labour utilisation approach adopted in the labor force survey from 1977 to 1982 have been discontinued, namely the studies of underutilisation by income and mismatch. The study of underutilisation by hours worked has however been retained.
2. As regards the unemployed, an additional question on "availability for work" has been added in the questionnaire.
3. Unpaid family workers who work at least one hour during the survey week are treated as employed; otherwise they are treated as unemployed if available for work during the survey week. Prior to 1983, unpaid family workers who worked less than 20 hours during the reference week and did not want to work more were treated as outside the labour force.
4. "Persons waiting for farm season" used to mean "unpaid family workers" who usually worked in farm but did not work during the survey week because of waiting for agricultural season, and were classified as outside the labour force. Since 1983, "unpaid family workers" who did not work even one hour and were not available for work during the survey week because it is not a suitable season, but who usually work, are treated as "seasonally inactive labour force" as distinct from the "current labour force", but are still included in the total labour force.

18. Documentation

For survey results and methodological informations see:

National Statistical Office, Office of the Prime Minister: "Report of the Labor Force Survey" (Whole Kindgom)" (Bangkok). Each survey round is the subject of a publication which is issued about 15 months after the survey reference period. The latest publication available refers to Round 2 of May 1987.

In addition, non-published more detailed information is tabulated and kept in computer print-out forms, which are available on request through the Labour Force Statistics Section, Population Survey Division, National Statistical Office.