Technical Notes on the Survey on Overseas Filipinos (SOF)

Release Date: 

Tuesday, December 12, 2017
The Survey on Overseas Filipinos (SOF) is a nationwide survey that seeks to gather information on Filipino citizens who left for abroad during the last five years.  It is a rider survey to the October round of the Labor Force Survey every year.
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 (LFS) 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.  In 1992, the section of international migration was included in the SOW questionnaire.  And in 1993, the SOW was renamed to SOF.
The SOF aims to provide data on overseas Filipinos particularly the OCWs and their contribution to the economy.  Specifically, the survey has the following objectives:
  • To obtain national estimates on the number of overseas Filipinos including overseas workers and their socio-economic characteristics; and 
  • To provide estimates on the amount of cash and in kind transfer received by the families and mode of remittances.
For purposes of the survey, only those family members who traveled outside of the Philippines within the last five-year reference period (e.g., if with reference to the 2016 SOF - from October 2011 to September 2016) for any reasons are included.
The authority and mandate of the Philippine Statistics Authority (PSA) to the Survey on Overseas Filipinos  emanates from Republic Act (RA) No. 10625.
As provided in Article 5, Rule 4 of the Implementing Rules and Regulations (IRR) of RA 10625, otherwise known as the Philippine Statistical Act of 2013, the PSA is primarily responsible for all national censuses and surveys, sectoral statistics, consolidation of selected administrative recording systems and compilation of national accounts.
Under Article 6, Rule 5, the PSA is mandated to prepare and conduct statistical sample surveys on all aspects of socioeconomic life including agriculture, industry, trade, finance, prices and marketing information, income and expenditure, education, health, culture and social situations for the use of the government and the public. 
Section 26 of RA No. 10625, stipulates that individual data furnished by a respondent to statistical inquiries, surveys, and censuses of the PSA shall be considered privileged information and such shall be inadmissible as evidence in any proceeding.  The PSA releases data gathered in the form of summaries or statistical tables, in which no reference to an individual, corporation, association, partnership, institution or business enterprise shall appear.
Likewise, Section 27 of RA No. 10625 states that a person, including parties within the PSA Board and the PSA, who breach the confidentiality of information, whether  by carelessness, improper behavior, behavior with malicious intent, and use of confidential information for profit shall be liable to a fine of five thousand pesos (P5,000.00) to not more than ten thousand pesos (P10,000.00) and or imprisonment of three months but not to exceed one year, subject to the degree of breach of information.
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 reporting unit is the household, which means the statistics emanating from this survey refer to OFWs who are members of private households.  Institutional population is not within the scope of the survey.  
Two forms were used in this survey, namely: (1) SOF Form 1 which gathers the socio-economic characteristics of overseas Filipinos and, (2) SOF Form 2 which is a control form.
Starting with the October 2016 round, the SOF, as a rider survey to the LFS, used the sampling design of the 2013 Master Sample (MS) for household-based surveys.  The 2013 MS was used starting April 2016. This section describes the sampling domains in the 2013 MS, the primary sampling units used, the 2x2x2 implicit stratification and sample allocation scheme, and the sample size used for the October 2016 round of the LFS and SOF.
F1.  Sampling Domain
To provide sub-national or provincial level statistics with precise estimates the 2013 MS has 117 major domains as follows: 81 provinces (including the newly created province Davao Occidental); 33 highly urbanized cities (including 16 cities in the National Capital Region); and 3 other areas (Pateros, Isabela City, and Cotabato City).
F2.  Primary Sampling Units  
In the 2013 Master Sample Design each sampling domain (i.e. province/HUC) is divided into exhaustive and non-overlapping area segments known as Primary Sampling Units (PSUs) with about 100 to 400 households. Thus, a PSU can be a barangay/Enumeration Area (EA) or a portion of a large barangay or two or more adjacent small barangays/EAs. 
F3.  2x2x2 Implicit Stratification 
The PSUs are then ordered according to the following: (1) North-South/West-East Geographic Location; (2) Decreasing Proportion of HHs with Overseas Worker; and (3) Decreasing Wealth Index.
F4.  Sample Allocation Scheme 
For each domain, a total of 4 sample replicates will be allotted for each survey round.  However, the total number of sample SSUs will be allotted proportionately to the measure of size of the PSU.  Thus, a PSU with only 100 HHs would have less number of sample HHs than PSUs with 400 HHs but on the average there will be 12 sample HHs allotted for each PSUs in Highly Urbanized Cities (HUCs) and an average of 16 sample HHs for every PSUs in province domains. 
A total national sample of 42,768 sample HHs (rounds with Batanes sample) or 42,576 sample HHs (rounds without Batanes sample) will be allotted per survey round. 
F5.  Sample Size
The SOF involved the interview of a national sample of about 45,000 households deemed sufficient to provide reliable information on the number of OFWs and their characteristics at the national and regional level.   
G1.   Who are the Overseas Filipinos?
For purposes of this survey, the following are considered as overseas Filipinos as long as their departure occurred within the given five-year period:
1. Filipino OCWs 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 either be landbased or seabased.
a. Landbased workers – these are OCWs 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.
b. Seabased workers – these are OCWs 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.
2. Other Filipino workers abroad with a valid working visa or work permit.  Included also are crew members of airplanes such as pilots, stewards, stewardesses and others whose employers are foreign nationals.
3. Filipino workers other than those who work on contractual basis.  These include Filipinos who went out of the country through backdoor means and worked there during the reference period.
4. Filipinos whose place of employment is outside the Philippines but whose employer is the Philippine government.
5. Filipinos who are sent abroad by the Philippine government or by private institutions for training, scholarship or any other similar purpose, even if they are known to be working abroad.
6. Filipinos working in other countries who are hired as consultants/ advisors of international organizations such as the United Nations, International Monetary Fund and others.
7. Filipino immigrants and residents in other countries.
8. Filipinos abroad who are holders of other types of non-immigrant visa such as visa for tourist/visitor, student, medical treatment and others.
G2.    Who are the Overseas Filipino Workers?
OFWs include OCWs who were presently and temporarily out of the country during the reference period to fulfill an overseas contract for a specific length of time, or who were presently at home on vacation during the reference period but still had an existing contract to work abroad.  Also included were other Filipino workers abroad with valid working visas or work permits. Those who had no working visa or work permit (tourists, visitors, students, those seeking medical treatment, and other types of non-immigrants) but were presently employed and working full time in other countries were also classified as OFWs.
The SOF has the following limitations:
  1. Ideally, information about overseas Filipinos should be obtained directly from them.  However, since this is not always possible, the information has to come from their relatives or any member of the household who knows the person who left for abroad.  The OFWs included in this report are those whose families still reside in the country as of the time of survey visit.
  2. The OFWs covered in this report were those working abroad during the period April 1 to September 30.  The workers who were at home on vacation from their jobs abroad who left earlier than April 1 of the reference year were also included in this report as long as they worked during the specified reference period.
  3. The SOF did not ask for the total salary received by the OFWs. Hence, the remittances presented in the results may just be a part of the total salary received by the OFWs.
  4. Starting  April 2016 round of the Labor Force Survey (LFS), the 2013 Master Sample (MS) design has been adopted.  The number of sample household is around 45,000. The SOF, being a rider to the LFS, has adopted the 2013 MS starting October 2016.  
  5. The 2012 Philippine Standard Occupational Standard (PSOC) was adopted starting October 2016.  The 1992 PSOC had  been used prior to October 2016.