The data collection of the characteristics of overseas workers started in 1982 using a one-page rider questionnaire in the Integrated Survey of Households (ISH) and continued until 1986. In 1987, during the revision of the ISH Form 2 or the Labor Force Survey questionnaire, a column indicator for overseas contract workers (OCWs) was added to get the estimate of the number of OCWs. With the increasing demand for information on overseas workers, the Survey on Overseas Workers (SOW) was resumed in 1991 revising the previous questionnaire to generate more comprehensive data. Data on international migration were gathered in the 1988 National Demographic Survey (NDS). With the expanded coverage of the 1993 NDS on health and immunization, the section on international migration was deleted from the NDS but it was recommended for inclusion in SOW starting 1992. In 1993, the SOW was renamed to Survey on Overseas Filipinos (SOF).
The Survey on Overseas Filipinos (SOF) was conducted as a rider to the October 2008 Labor Force Survey (LFS).
The survey was designed to gather national estimates on the number of overseas workers, their socio economic characteristics and other information pertaining to the overseas workers who worked or have worked abroad from April to September 2008. The remittances of the Overseas Filipino Workers (OFWs) in cash or in kind were also accounted for the specified reference period. The SOF data are useful inputs to government planners, migrant advocates, researchers, academes, concerned citizens, and other data users to the formulation of policies and programs for the welfare of the overseas Filipino.
Kind of Data
Sample survey data [ssd]
Unit of Analysis
v2.0: edited data, for public use.
Data gathered in the survey include the demographic and economic characteristics of OFWs and the remittances they send to their families here in the Philippines. Related information such as the place of destination, length of stay abroad, type of work abroad, date of departure and return were also included.
The geographic coverage consists of the country's 17 administrative regions defined in Executive Order (EO) 36 and 131. The 17 regions are:
National Capital Region (NCR)
Cordillera Administrative Region (CAR)
Region I - Ilocos Region
Region II - Cagayan Valley
Region III - Central Luzon
Region IV-A - CALABARZON
Region IV-B - MIMAROPA
Region V - Bicol Region
Region VI - Western Visayas
Region VII - Central Visayas
Region VIII - Eastern Visayas
Region IX - Zamboanga Peninsula
Region X - Northern Mindanao
Region XI - Davao Region
Region XII - SOCCSKSARGEN
Autonomous Region in Muslim Mindanao (ARMM)
Overseas Filipinos whose departure occured within the last five years and who are working or had worked abroad during the past six months (April to September) of the survey period.
For purposes of this survey, overseas workers are the following:
Filipino overseas contract workers (OCW) who are presently and temporarily out of the country to fulfill an overseas work contract for a specific length of time or who are presently at home on vacation but still has an existing contract to work abroad. They may be landbased or seabased.
Landbased workers ? these are overseas contract workers who are hired either by direct hiring of an employer abroad; or through the assistance of Philippine Overseas Employment Administration (POEA);
or through a private and licensed recruitment agency. They may have returned to the Philippines for a vacation (annual or emergency leave), or have transferred to other employers, or were rehired by their former employer.
Seabased workers ? these are overseas contract workers who worked or are working in any kind of international fishing/passenger/cargo vessels. Included also are OCWs who worked or are working for a shipping company abroad.
Other Filipino workers abroad with a valid working visa or work permits. Included also are crew members of airplanes such as pilots, stewards, stewardesses, etc.
example: Filipinos working in countries such as U.S., Taiwan, Saipan, etc. with a working visa.
Filipinos abroad who are holders of other types of non-immigrant visa such as tourist/visitor, student, medical and others but are presently employed and working full time.
Persons not considered as overseas workers are:
Filipinos whose place of employment is outside the Philippines but whose employer is the Philippine government. Examples are Filipinos who worked or are working in Philippine embassies, missions and consulates abroad.
Filipinos who are sent abroad by the Philippine government or by private institutes for training, scholarship or any other similar purpose, even if they are known to be working abroad. Note that students who are sent abroad by private individual who are working or had worked there are excluded in this category.
Filipinos working in other countries who are hired as consultants/advisers of International organization such as the United Nations International Monetary Fund, etc.
Immigrants to other countries even though they are working abroad.
Producers and sponsors
National Statistics Office
National Statistics Office
The Survey on Overseas Filipinos, as a rider to the Labor Force Survey (LFS), used the sampling design of the 2003 Master Sample (MS) for Household Surveys starting July 2003. The design of the Master Sample is described below:
The 2003 MS considers the country's 17 administrative regions as its sampling domain. A domain is referred to as a subdivision of the country in which estimates with adequate level of precision is generated. It must be noted that while there is demand for data at the provincial level (and to some extent municipal and barangay levels), these were not treated as domain because of its large number (more than 80) and the large resource requirement it would entail.
2. Sampling Frame
As in most household surveys, the 2003 MS made use of an area sample design. For this purpose, the Enumeration Area Reference File (EARF) of the 2000 Census of Population and Housing (CPH) was utilized as sampling frame. The EARF contains the number of households by enumeration area (EA) in each barangay.
This frame was used to form the primary sampling units (PSUs). With consideration of the period for which the 2003 MS will be in use, the PSUs were formed/defined as a barangay or a combination of barangays with at least 500 households.
3. Sample Size
The 2003 MS consists of a sample of 2,835 PSUs of which 330 were certainty PSUs and 2,505 were non-certainty PSUs. The entire MS was divided into four sub-samples or independent replicates, such as a quarter sample contains one fourth of the PSUs found in one replicate; a half sample contains one-half of the PSUs in two replicates. The SOF as a rider to the LFS utilizes the full sample.
The 2003 MS considers the 17 regions of the country as the primary strata. Within each region, further stratification was performed using geographic groupings such as provinces, highly urbanized cities (HUCs), and independent component cities (ICCs). Within each of these substrata formed within regions, the PSUs were further stratified, to the extent possible, using the proportion of strong houses (PSTRONG), indicator of engagement in agriculture of the area (AGRI), and a measure of per capita income as stratification factors (PERCAPITA).
PSTRONG is defined to be the percentage of occupied housing units that are classified as made of strong materials in terms of both the roof and outer walls, based on the data from the 2000 CPH. A roof is considered made of strong material if it is made of either galvanized iron, aluminum, concrete/clay tile, half galvanized-half concrete, or asbestos. The outer wall is considered made of strong material if it is made of concrete, brick, stone, wood, half concrete-half wood, galvanized iron, asbestos or glass.
AGRI was determined in the following way: initially, an indicator variable was computed at the barangay level. That variable has the value 1 if more than 50 percent of the households in the barangay were engaged in agriculture or fisheries and 0 otherwise, based on the 2000 CPH Barangay Schedule. To obtain a measure at the PSU level, a weighted average of the barangay indicator variable was computed for all the barangays within the PSU, weighted by the total number of households in the barangay. Thus, the value of AGRI at the PSU level lies between 0 and 1.
PERCAPITA is defined as the total income of the municipality divided by the total population in that municipality. Note that the PERCAPITA value of the PSUs is the same if the PSUs are in the same municipality. The data on municipal income refer to year 2000 and were taken from the Department of Finance. However, if the 2000 municipal income was not reported to the Bureau of Local Government Finance (BLGF), 2001 income was used. If no 2000 or 2001 municipal income was reported, the income classification from the BLGF for this municipality was obtained. Using the data on income, which are presented in income intervals, the average of the lower and the upper values of the income interval for the municipal class to which this municipality belongs were determined.
5. Sample Selection
The 2003 MS consists of a sample of 2,835 PSUs. The entire MS was divided into four sub-samples or independent replicates, such as a quarter sample contains one fourth of the total PSUs; a half sample contains one-half of the four subsamples or equivalent to all PSUs in two replicates.
The final number of sample PSUs for each domain was determined by first classifying PSUs as either self-representing (SR) or non-self-representing (NSR). In addition, to facilitate the selection of subsamples, the total number of NSR PSUs in each region was adjusted to make it a multiple of 4.
SR PSUs refers to a very large PSU in the region/domain with a selection probability of approximately 1 or higher and is outright included in the MS; it is properly treated as a stratum; also known as certainty PSU. NSR PSUs refers to a regular too small sized PSU in a region/domain; also known as non certainty PSU. The 2003 MS consists of 330 certainty PSUs and 2,505 non-certainty PSUs.
To have some control over the sub-sample size, the PSUs were selected with probability proportional to some estimated measure of size. The size measure refers to the total number of households from the 2000 CPH. Because of the wide variation in PSU sizes, PSUs with selection probabilities greater than 1 were identified and were included in the sample as certainty selections.
At the second stage, enumeration areas (EAs) were selected within sampled PSUs, and at the third stage, housing units were selected within sampled EAs. Generally, all households in sampled housing units were enumerated, except for few cases when the number of households in a housing unit exceeds three. In which case, a sample of three households in a sampled housing unit was selected at random with equal probability.
An EA is defined as an area with discernable boundaries within barangays consisting of about 150 contiguous households. These EAs were identified during the 2000 CPH. A housing unit, on the other hand, is a structurally separate and independent place of abode which, by the way it has been constructed, converted, or arranged, is intended for habitation by a household.
The Survey on Overseas Filipinos is a rider to the October round of the Labor Force Survey every year. Column 11 of the Labor Force Survey questionnaire (ISH Form 2) is used to identify the overseas contract worker and other overseas Filipino worker among the household members.
All of these household members identified as overseas Filipino workers have corresponding completed SOF questionnaires.
Calculation of Basic Weights:
Following a standard approach, the weights to be used in analyzing surveys based on the 2003 MS are developed in three stages.
First, base weights are computed to compensate for the unequal selection probabilities in the sample design.
Second, the base weights are adjusted to compensate for unit non-response.
Third , the non-response adjusted weights are further adjusted to make some weighted sample distributions to conform to some known population totals.
Final Survey Weight
The final survey weight assigned to each responding unit is computed as the product of the base weight, the non-response adjustment, and the population weighting adjustment. The final weights should be used in all analyses to produce valid estimates of population parameters.
Dates of Data Collection
Data Collection Mode
The Regional Directors (RDs), Provincial Statistical Officers (PSOs), Provincial Statisticians and selected District Statistics Officers (DSOs)/ Statistical Coordination Officers (SCOs) strictly supervised the conduct of the survey.
Prior to start of field supervision, all field personnel who are authorized to supervise the survey operation were required to prepare an itinerary of travel to insure effective and close supervision of the enumerators. A copy of the itinerary of travel were required to be available in the field office so that in case some problems or other matters require the attention of a supervisor, then he can be located easily.
It is the responsibility of the supervisors to give prompt action to problems in the field. The RDs, PSOs and their assistants should visit enumerators (ENs) within their jurisdiction to find out for themselves if instructions are being followed.
Central Office Statisticians were assigned to provinces to supervise and monitor the conduct of the survey.
Data Collection Notes
There are three levels of training:
1. The first level involves the training of task force members conducted at the Central Office participated by selected central office personnel, selected regional or provincial staff.
2. The second level training is held at the Regional Offices participated by the Provincial Statistical Officers, Regional Statisticians, and Provincial Statisticians. Regional or provincial staff who attended the Task Force Training will act as trainers during the second level training.
3. The third level training is held at the Provincial Offices participated by the District Statistics Officers, Statistical coordination Officers and hired Statistical Researchers. The provincial staff who attended the second level training will act as trainers in this level of training.
The enumeration period started on the second week up to the end of October including Saturdays. The total mandays given to each enumerator to complete his/her workload depended on the assigned sample areas but not more than 21 days.
The Survey on Overseas Worker Filipinos is a rider to the Labor Force Survey (LFS). All households from the sample barangays/EAs were administered with the LFS questionnaire (ISH Form 2) with an output of six to eight households per day.
A courtesy call to the head of the Barangay were done to inform that there is an on-going survey in their area.
There was no translation of questionnaire into local dialect.
National Statistics Office
SOF Form 2, the household (HH) control form, is the basis for determining households with members who are overseas. Only those sample HHs with members overseas shall be given SOF Form 1, that is, those HHs that responded "YES" to the question, "Is there a family member who left for abroad at anytime during the period October 2003 to September 2008" in column 4 of SOF Form 2.
There may be overseas Filipinos (OF) who were listed as OFs in Column 11 of ISH Form 2 (Labor Force Survey Questionnaire) though their departure may be outside the 5-year reference period since there is no cut-off period for LFS (Labor Force Survey). In this case, the OF is listed in the control form but is not assigned an SOF Form 1. There are also previous OFs who went abroad anytime in October 2003 to September 2008 and are now regular members of the HH (with code "5" in Column 11 of ISH Form 2). They are reported in SOF Form 2 and assigned an SOF Form 1.
SOF Form 1 is a two-page questionnaire designed to gather data on the number and socioeconomic characteristics of overseas Filipinos and their remittances.
Each sample HH of the ISH with family members who left for abroad during the reference period are given one (1) SOF questionnaire. SOF Form 1 allows the recording of answers for only one person in the sample HH. In cases where there is more than one family member who left abroad, additional questionnaire/s are provided, thereby asking the same set of questions for each person who left for abroad.
The entries for the marital status and highest grade completed may not be consistent with the entries in ISH Form 2 since these refer to the status of the person at the time of departure. Note that the entry in the highest grade completed in LFS should be equal or higher than that reported in SOF.
Prior to the submission of questionnaires to the Central Office, it was the responsibility of each interviewer to review each questionnaire when the interview is finished. The review was done before leaving the household to make sure that all answers are clear, legible and complete. Also, skipping instructions were checked if correctly followed.
Manual processing was done at the Central Office. This process included the folioing of the questionnaires, completeness and consistency checking of the responses, editing and coding of responses. This was done prior to machine processing.
Estimates of Sampling Error
Chief, Income and Employment Statistics Division
National Statistics Office
Chief, Databank and Information Systems Division
National Statistics Office
This Survey conforms to the provisions of confidentiality stated under Section 4 of Commonwealth Act No. 591, which says that the "Data furnished to the Bureau of Census and Statistics (BCS) by an individual, corporation, partnership, institution or business enterprise shall not be used as evidence in any court or in any public office either as evidence against the individual, corporation, association, partnership, institution, or business enterprise from whom such data emanates; nor shall such data or information be divulged to any person except authorized employees of the BCS acting in the performance of their duties; nor shall such data be published except in the form of summaries or statistical tables in which no reference to an individual, corporation, association, partnership, institution or business enterprise shall appear."
Authorization to use this data is granted only to the client or data user and persons within its organization, if applicable. Under no circumstances shall the client reproduce, distribute, sell or lend the entire data or parts thereof to any other data user apart from himself or that of authorized employees in his organization. The National Statistics Office shall hold the data user fully responsible for safeguarding the data from any unauthorized access or use.
Any report, paper or similar articles, whether published or not, emanating from the use of this data shall give appropriate acknowledgement as suggested herein, “2008 Survey on Overseas Filipinos, National Statistics Office, Philippines,” as the source of basic data. The data user or client is encouraged to provide the NSO with a copy of such report, paper or article. It is understood that unless expressly allowed by the client, such report, paper or article shall not be used for any purpose other than monitoring.
Income and Emplyment Statistics Division
National Statistics Office
Databank and Information Systems Division
National Statistics Office
Disclaimer and copyrights
The National Statistics Office (NSO) gives no warranty that the data are free from errors. Hence, the NSO shall not be held responsible for any loss or damage as a result of the client's manipulation or tabulation of the data
The data user acknowledges that any available intellectual property rights, including copyright in the data are owned by the Philippines National Statistics Office.
DDI Document ID
Solficar P. Pescuela
Accelerated Data Program
International Household Survey Network
Editing for the IHSN Survey Catalog
Date of Metadata Production
DDI Document version
Version 01: Adopted from "DDI_PHL_2008_SOF_v2_M" DDI that was done by metadata producers mentioned in "Metadata Production" section.