Reference metadata describe statistical concepts and methodologies used for the collection and generation of data. They provide information on data quality and, since they are strongly content-oriented, assist users in interpreting the data. Reference metadata, unlike structural metadata, can be decoupled from the data.
Economic Statistics Department, Business Statistics Unit
1.3. Contact name
Confidential because of GDPR
1.4. Contact person function
Confidential because of GDPR
1.5. Contact mail address
Instituto Nacional de Estatística
Avenida António José de Almeida 1000-043 Lisboa Portugal
1.6. Contact email address
Confidential because of GDPR
1.7. Contact phone number
Confidential because of GDPR
1.8. Contact fax number
Confidential because of GDPR
2.1. Metadata last certified
21 November 2025
2.2. Metadata last posted
21 November 2025
2.3. Metadata last update
21 November 2025
3.1. Data description
Global Value Chains (GVC) comprise the full range of cross-border activities required to bring a product or service from conception through the different production and delivery phases to final consumers.To stay competitive, enterprises increasingly organise their production globally in GVC by breaking up their value chains into smaller parts supplied by a growing number of providers located worldwide. GVC statistics can help measure organisational and spatial patterns in domestic, regional and global value chains, and monitor their effect on employment, wages, value-addition, innovation, skills, firm survival and turnover. From an EU policy perspective, such analysis provides crucial data on the movement of EU jobs to extra-EU countries, dependency on foreign parts of the chain, and the EU's integration in global value chains. Moreover, in the post-COVID-19 world, there are reports of a shortening of GVCs and a de-globalisation trend resulting from the COVID-19 pandemic. Therefore, statistics on GVC are necessary to support policies on trade, job sustainability and economic development.
One of the first efforts to measure the GVC phenomenon in Europe came with the international sourcing (IS) survey in 2007, lauched through a common developed questionnaire used by all participating countries. Since 2007, Eurostat has supported and actively contributed to developing and establishing the IS and GVC surveys which were carried out in 2012, 2018, 2021 and the latest one in 2024, already under the EBS Regulation. These efforts culminated with the international sourcing survey (now renamed GVC survey) being included as official statistics in Regulation (EU) 2019/2152 on European Business Statistics ('the EBS Regulation'). Under the EBS Regulation and, as described in the Regulation (EU) 2022/918 (GVC Implementing act) that was adopted on 13 June 2022, the survey's scope has increased to encompass the GVC arrangements and impact on the EU Member States. Targeted topics may change between consecutive surveys to better capture globalisation trends and policy requirements.The 2024 edition of the survey covered the reference period 2021-2023 and was the first mandatory edition following its official integration into the collection of information on European Business Statistics required under the EBS Regulation.
The GVC dataset contains ten variables defined in Implementing Regulation (EU) 2022/918. These cover:
Business functions:
Number of employees and self-employed persons
GVCs:
Number of enterprises purchasing goods from abroad
Number of enterprises supplying goods abroad
Number of enterprises purchasing services from abroad
Number of enterprises supplying services abroad
International sourcing:
Number of enterprises carrying out international sourcing
Number of jobs created in the enterprise as a result of international sourcing
Number of jobs lost or relocated abroad as a result of international sourcing
Number of enterprises that have carried out or considered carrying out international sourcing
Events impacting GVC arrangements:
Number of active enterprises
For variables (2)-(5), the dataset includes only enterprises that report at least EUR 100 000 in goods or services purchased from or supplied abroad in the final year of the reference period.
All data are provided as absolute values and presented by NACE activity, business function, geographical partner area, size class, motivation and barrier types, and other breakdowns required by the regulation.
As already mentioned, most of the data are collected via a common questionnaire sent to enterprises in each EU country by their NSAs. The following data may be collected or obtained from registers or other statistical or administrative data sources:
The main economic activity of the enterprise at the end of the last year of the reference period, year T;
The number of employees and self-employed persons in the last year of the reference period, year T;
Information about participation in an enterprise group.
In summary, the aim of the International Sourcing and Global Value Chains survey is to produce statistical information on enterprises' economic globalisation practices by collecting information on business functions, international sourcing practices, global value chains and the effects of the international economic situation on those practices.
Name of data collection in Portugal for the reference year 2021-2023: Inquérito ao Sourcing e às Cadeias de Valor Globais 2021-2023
3.2. Classification system
Classification systems used in the GVC statistics are as follows:
NACE Rev.2, Statistical Classification of Economic Activities in the European Community (NACE): used to classify economic activities for all variables.
CBF, Statistical Manual on the Classification of Business Functions: used to create Business functions, which, in turn, also follow the harmonised list defined in the GVC implementing act, distinguishing core and support functions as well as specific functional categories such as production of goods, ICT services, marketing, engineering, and R&D.
Geographical classifications follow the breakdowns prescribed in Regulation (EU) 2022/918 of 13 June 2022, including EU Member States, Extra-EU, and specific partner regions (e.g. China, India, USA and Canada, Central and South America, Africa).
Classifications for job skills follow the high-skilled / not-high-skilled distinction set out in the GVC Compilers’ Manual.
The GVC statistics cover market producers classified under NACE Rev.2 Sections B to N. This sector coverage is defined in Implementing Regulation (EU) 2022/918 of 13 June 2022 and applies uniformly to all variables. Only enterprises with 50 or more employees and self-employed persons in the final year of the reference period are included.
3.4. Statistical concepts and definitions
The GVC questionnaire includes the following modules:
Module 1: Business functions - contains questions on the distribution of employees and self employed persons per business function in the enterprise’s structure;
Module 2: GVC arrangements focuses on the purchasing and supply aspects of international trade in goods and services and tries to measure the GVC trade and some of its characteristics;
Module 3: International sourcing contains questions that help measure international sourcing within and outside the enterprise group, business functions being internationally sourced, and locations of international sourcing and jobs that are relocated abroad or created as a result of international sourcing activity per business function;
Module 4: Motivation and barriers for international sourcing focuses on two key questions: 1) why are enterprises motivated to source internationally, and 2) what barriers are stopping them from sourcing or making it more difficult to do so;
Module 5: Impact of recent events on economic globalisation is a new module that tests a GVC’s resilience to recent global events. All modules could have optional questions or response options.
The statistical unit used for the GVC statistics is the enterprise, as defined in Regulation (EU) 2019/2152 of 27 November 2019 on European business statistics and the Business Register Regulation (EC) No 177/2008 of 20 February 2008.
In Portugal, the reporting unit considered in the GVC 2021-2023 was the legal unit and the statistical unit considered was the enterprise (sampling at enterprise level and data collection at legal unit level).
3.6. Statistical population
The target population of GVC statistics for the reference period 2021-2023 consists of all market-producing enterprises in NACE Rev.2 sections B to N, with 50 or more employees and self-employed persons in the final year of the reference period. For variables (2)-(5), only enterprises reporting at least EUR 100 000 of goods or services purchased from or supplied abroad are included, in line with the Annex of Implementing Regulation (EU) 2022/918 of 13 June 2022.
NACE Rev. 2 sector
Total number of enterprises with 50+ persons employed
B
23
C
2 452
D
20
E
76
F
510
G
1 050
H
355
I
456
J
396
K
6
L
23
M
328
N
408
Total
6 103
NACE Rev. 2 sector
Total number of persons employed in enterprises with 50+ persons employed
B
3 745
C
390 504
D
8 503
E
17 057
F
76 513
G
271 597
H
90 645
I
74 320
J
103 907
K
463
L
2 774
M
69 179
N
220 603
Total
1 329 810
3.7. Reference area
The reference area is the national economic territory of Portugal (Continente, Região Autónoma dos Açores and Região Autónoma da Madeira), as defined in Regulation (EU) 2019/2152 of 27 November 2019 for European business statistics. Units located within the national territory and covered by national statistical legislation are included.
3.8. Coverage - Time
The GVC statistics refer to the triennial reference period 2021–2023, as defined in Implementing Regulation (EU) 2022/918 of 13 June 2022. All data transmitted relate exclusively to this three-year reference period.
3.9. Base period
Not applicable. No base year or index is used, as the data are compiled as absolute values within the triennial reference period defined by Regulation (EU) 2022/918 of 13 June 2022.
All variables in the GVC dataset are compiled and transmitted in absolute values, in accordance with the measurement unit specified in Implementing Regulation (EU) 2022/918 of 13 June 2022. No percentages, indexes, ratios or other derived units are transmitted to Eurostat. This unit applies uniformly to all variables and all breakdowns required by the regulation.
The reference period for the GVC statistics is 2021-2023, in accordance with Implementing Regulation (EU) 2022/918 of 13 June 2022. Variables cover activities that may have occurred during this three-year period.
Variables (1)-(5) refer specifically to the final year of the period (2023).
Variables (6)-(10) cover actions that took place at any time between 1 January 2021 and 31 December 2023.
6.1. Institutional Mandate - legal acts and other agreements
GVC statistics are produced under the legal framework of European business statistics. The main legal bases are Regulation (EU) 2019/2152 of 27 November 2019 on European business statistics and Implementing Regulation (EU) 2022/918 of 13 June 2022, which defines the variables, population, breakdowns and transmission deadlines for the 2021-2023 reference period. The topic Global Value Chains is listed in Annex I of Regulation (EU) 2019/2152.
Statistics Portugal collects and compiles these data under the national statistical Law no. 22/2008, of 13th May 2008), which defines the general basis of the National Statistical System, provides the legal mandate for data collection, access to administrative sources and the obligation of enterprises to respond. Since its enactment in 2008, Law no. 22/2008 has been subject to various amendments and updates, usually driven by the need to align Portugal’s statistical practices with EU regulations or evolving international standards. One of the notable amendments to Law no. 22/2008 was in 2018, when Portugal made modifications to improve the efficiency of the national statistical system, better integrate emerging technologies (e.g., digital platforms for data collection), and ensure compliance with EU regulations on statistical data management. There is no ‘derogation’ from Law no. 22/2008 on the National Statistical System (SEN), but rather mechanisms for the delegation of powers and complementary legislation. The National Statistics Institute (INE) may delegate the production of official statistics to other public entities, which are subject to SEN rules, European legislation and the European Statistics Code of Practice, as mentioned in Statistics Portugal website.
Regulation (EC) 223/2009 of 11 March 2009 on European statistics provides the general legal framework for professional independence, data quality and statistical confidentiality.
Data are transmitted to Eurostat in accordance with Regulation (EC) 223/2009 of 11 March 2009 and Articles 17 and 18 of Regulation (EU) 2019/2152 of 27 November 2019, which govern data and metadata transmission. Only authorised staff have access to identifiable information at the national level, and no microdata are shared outside the national statistical authority. Data transmitted to Eurostat are handled under strict confidentiality rules and disseminated only in aggregated form. Secure transmission channels are used for all data transfers.
Confidentiality of statistical data is ensured by national statistical legislation, Regulation (EC) No 223/2009 of 11 March 2009 on European statistics and Regulation (EU) 2019/2152 of 27 November 2019. These acts establish the legal obligation to protect confidential information, ensure professional secrecy and restrict the use of data to statistical purposes only. Access to identifiable information is limited to authorised staff, and confidential data cannot be used for administrative, fiscal or legal purposes.
At national level: The Statistical Confidentiality Policy of Statistics Portugal is based on the Constitution of the Portuguese Republic, Law 22/2008 of 13 May, which establishes the principles, rules, and structure of the National Statistical System, and in particular the Principle of Statistical Confidentiality (Article 6), Regulation 223/2009 of 11 March (Article 20 et seq.), as amended by Regulation 2015/759 of 29 April 2015, establishing the legal framework for the development, production, and dissemination of European statistics and Regulation (EU) 557/2013, of 17 June 2013, as regards access to confidential data for scientific purposes. Breaking the statistical confidentiality is punishable both disciplinary and criminally in accordance with item 32 of the referred law. It is also governed by the principles agreed between the EU Member States and inscribed in the European Statistics Code of Conduct (2nd revision/2017), in particular, Principle 5 on Statistical Confidentiality and, more broadly, the Fundamental Principles of Statistics Officials, established by the United Nations Statistical Commission in 1994 and approved by the United Nations General Assembly in January 2014 (Principle 6). Regarding the processing of personal data, the exercise of statistical activity also complies with Regulation (EU) 2016/679 of the European Parliament and of the Council of 27 April 2016, in its current wording, laying down rules for the protection of individuals with regard to the processing of personal data and to the free movement of such data and other applicable legislation in this matter. Please consult the Statistics Portugal's website for more information.
7.2. Confidentiality - data treatment
Confidential enterprise data are processed under strict disclosure control procedures. Primary and secondary suppression are applied in accordance with national confidentiality rules and ESS guidelines to prevent any direct or indirect identification of individual enterprises. Only aggregated data are transmitted to Eurostat, and microdata are not disseminated. Eurostat applies its own confidentiality rules to the aggregated data received, ensuring secure handling and safe dissemination.
According to the EBS specifications, at Statistics Portugal, primary confidentiality is flagged with “A” and secondary with “D”. The rule is that any cell with 1 or 2 enterprises shall be flagged with primary confidentiality (flag A). After that, one or more additional cells are flagged with “D” (secondary confidentiality) in order to protect the first ones set as confidential by primary confidentiality. Statistics Portugal does not follow the dominance rule and P-percent rule. The variable Number of enterprises is always disclosed. At Statistics Portugal confidentiality is applied using the software Tau-Argus, with which, cells with the lowest turnover are the first to be chosen for secondary confidentiality.
8.1. Release calendar
The dissemination of GVC statistics follows the national release calendar published on the Statistics Portugal website. Release dates are announced in advance and updated regularly in accordance with national dissemination policy and the ESS principles of impartiality and equal treatment. GVC results are released through the standard national dissemination channels. For the reference period 2021-2023, a press release on Global Value Chains was disseminated 10 months after the end of the reference period (T+10 months), which was in 31 October 2024.
The national release calendar is publicly available at Statistics Portugal website under the publication schedule section. It is accessible free of charge and updated regularly to reflect planned publication dates for statistical outputs, including GVC-related releases. The calendar ensures transparency and equal access for all users.
8.3. Release policy - user access
In line with the Community legal framework and the European Statistics Code of Practice, at Statistics Portugal all users have equal and simultaneous access to published GVC data at the time of release. No privileged pre-release access is granted. Dissemination follows Statistics Portugal standard user access and embargo rules, which are aligned with the national statistical legislation and ESS guidelines. At Statistics Portugal, the Dissemination policy lays down the fundamental principles governing the dissemination of official statistics, directly or indirectly produced under its responsibility. It should have as main reference the applicable principles of the National Statistical System: technical independence, statistical confidentiality, quality, and accessibility. Metadata and documentation are made available at the time of release.
GVC statistics are collected, compiled and transmitted every three years in accordance with Implementing Regulation (EU) 2022/918 of 13 June 2022.
National dissemination, where applicable, follows the same triennial cycle and usually takes place before the transmission of data and metadata to Eurostat.
10.1. Dissemination format - News release
A press release summarising key results on international sourcing and GVC participation is published at the time of dissemination at Statistics Portugal website in the section 'Press releases'.
10.2. Dissemination format - Publications
Not applicable.
10.3. Dissemination format - online database
A selection of aggregated GVC indicators, such as the number of enterprises sourcing abroad, purchasing or supplying goods and services abroad and the distribution of employment by business function, is published together with the press release, in the form of tables, at Statistics Portugal website in the section 'Press releases'.
10.4. Dissemination format - microdata access
Access to anonymised GVC microdata for scientific research is available under strict conditions defined by national statistical legislation. Researchers may access data through Statistics Portugal secure research environment after formal accreditation and approval. The academic community has special statistical requirements, notably for carrying out research work and preparing Masters and Doctoral theses. In this context, Statistics Portugal has established a Protocol with the Ministry of Education and Science, with a view to making it easier for researchers to access the statistics they need to carry out their activity. For that purpose, the Directorate-General for Education and Science Statistics (DGEEC) gives interested parties prior accreditation, and also provides them with all the necessary information. For each scientific research project, an application for accreditation must be made to DGEEC, which must include the following documents:
Accreditation and Statistical Data Transfer Request Form: pdf
Statement of Agreement: pdf
Privacy Notice and Consent: pdf
Before applying for credentials, researchers must consult the databases accessible under this protocol. The accreditation of researchers is only made for access to the databases available under this project. Free access to statistical micro-databases for research purposes is only possible for accredited researchers, in accordance with the Protocol established with Statistics Portugal.
10.5. Dissemination format - other
GVC results may also be presented in thematic reports, statistical yearbooks or public presentations organised by Statistics Portugal.
At national level, additional methodological notes are included in the disseminated analytical GVC press releases. Additional support information is given to users when needed or required. Also, at Statistics Portugal website is available for consultation the GVC methodological manual.
10.7. Quality management - documentation
Information on quality procedures is available in the national quality guidelines published by Statistics Portugal and follows the principles of the ESS quality framework, including relevance, accuracy, timeliness and coherence. More information about quality in statistics is available at Statistics Portugal website.
11.1. Quality assurance
Quality assurance is carried out in line with the ESS Quality Assurance Framework (QAF) and Statistics Portugal internal quality management system. Automated validation checks ensure completeness, internal consistency and compliance with definitions and breakdowns set out in Implementing Regulation (EU) 2022/918 of 13 June 2022. Additional manual and cross-domain checks compare GVC data with related sources such as SBS, FATS, TEC and STEC. All corrections, follow-up actions and methodological decisions are documented to maintain transparency and traceability.
11.2. Quality management - assessment
Overall data quality is assessed through evaluations of relevance, accuracy, coherence and completeness. Internal coherence between variables and breakdowns is reviewed, and external coherence is checked against other business statistics domains. Common limitations include item non-response in detailed breakdowns and occasional inconsistencies in administrative variables. Planned improvements include enhanced follow-up procedures, expanded use of register-based auxiliary variables and refinements to validation rules to further strengthen accuracy and reduce respondent burden.
At European level, the recommended use of the triennal Eurostat questionnaire template aims at improving comparability of the results among the countries that conduct the survey on GVC. Moreover, the European businesses statistics compilers’ manual for GVC provides guidelines and clarifications for the implementation of the surveys.
At national level:
When applying the GVC survey, Statistics Portugal follows the European businesses statistics compliers’ manual for GVC and the questionnaire template as established by Eurostat.
The GVC data is compared with previous reference periods data and checked for any large changes in the data.
12.1. Relevance - User Needs
Main user groups include national ministries responsible for economic, industrial and labour market policies, research institutes, academic users and Eurostat. These stakeholders use GVC information to analyse sourcing structures, international fragmentation of production and sectoral exposure to global shocks. The statistics also support evidence-based policy development related to supply chain resilience and strategic dependencies.
12.2. Relevance - User Satisfaction
No formal user satisfaction survey has been carried out specifically for the GVC domain. Informal exchanges with key users, including ministries and research organisations, suggest that the dataset meets current analytical needs. Users value the harmonised EU methodology and the detailed breakdowns by business function, activity and geographical area. Some users have expressed interest in more frequent updates, although the triennial cycle is defined in the regulation.
12.3. Completeness
All mandatory variables and breakdowns required by Implementing Regulation (EU) 2022/918 of 13 June 2022 were transmitted for the 2021-2023 reference period. The 1 percent rule was not applied. Data cover all required combinations of NACE sections B-N, size classes, business functions and geographical areas as specified in the regulation.
13.1. Accuracy - overall
Overall accuracy is assessed using checks on coverage, internal coherence and consistency with related business statistics. Most units in the target population provided usable data, and validation procedures reduced the impact of inconsistent responses. Some uncertainty remains for detailed variables, particularly those requiring subjective assessments such as sourcing motivations and barriers.
13.2. Sampling error
Where a sample is used, sampling error may affect the accuracy of estimates. Stratified sampling designs typically ensure adequate representation of size classes and key industries. Although formal sampling error indicators are not produced for this domain, the stratification and weighting procedures are designed to support representativeness across NACE sections B-N and enterprises with 50 or more persons employed.
13.3. Non-sampling error
Non-sampling errors constitute the main potential source of inaccuracy in the GVC dataset. Checking of data was based on built-in checks within the web-questionnaire. A complete set of validation rules, oriented to the functioning of the routing and filter questions, was developed and incorporated into the web-questionnaire. These set of validation rules does not allow for item non-responses and does not allow, in most cases, the registration of data that didn’t verify the defined coherence tests. Follow-up contacts are made to solve inconsistent responses or misinterpretation of business function categories. Coverage errors are limited due to the use of the statistical business register for population and sample construction. Overall, non-sampling errors have a moderate but manageable effect on the final results, and established validation and imputation procedures help to minimise their impact.
Approximately 26% of surveyed enterprises required additional follow-up contacts to clarify or correct responses.
The set of validation rules incorporated into the electronic questionnaire does not allow for item non-responses.
No imputations are made for total non-responses, so the disclosure of information is associated with the response rate obtained.
The survey response rate for the reference period 2021-2023 was 84.2% (every efforts are made to achieve a response rate grater than 80%)
Data is reported to Eurostat grossed up to the enterprise population level.
The number of responding enterprises and unweighted response rates
NACE Rev. 2 sector
Number of enterprises with 50+ persons employed
Unweighted response rates (per cent)
B
15
78,9%
C
423
83,1%
D
19
95,0%
E
25
80,6%
F
75
73,5%
G
441
85,1%
H
105
92,9%
I
39
83,0%
J
113
89,7%
K
6
100,0%
L
11
78,6%
M
80
84,2%
N
99
79,8%
Total
1 451
84,2%
Note: Unweighted response rates give the coverage of responses, measured by the number of responding enterprises, compared to the number of enterprises in the sample.
The number of persons employed in the responding enterprises and weighted response rates
NACE Rev. 2 sector
Number of persons employed in enterprises with 50+ persons employed
Weighted response rates (per cent)
B
3 185
85,0%
C
165 424
42,4%
D
8 423
99,1%
E
5 829
34,2%
F
21 832
28,5%
G
202 141
74,4%
H
63 448
70,0%
I
16 846
22,7%
J
63 550
61,2%
K
463
100,0%
L
1 925
69,4%
M
33 327
48,2%
N
79 755
36,2%
Total
666 148
50,1%
Note: Weighted response rates give the coverage of responses, measured by employment, compared to the total number of persons employed in enterprises with 50+ persons employed.
14.1. Timeliness
Data and metadata were transmitted to Eurostat within the legal deadline of T+21 months. Processing stages, including data collection, validation and preparation for transmission, were completed according to the national timetable. The transmission of data from Portugal took place approximately 3 months before the deadline.
14.2. Punctuality
All internal milestones in the national GVC production process were met in line with the planned schedule. Data collection, editing and validation activities followed the established timetable. The Press release with the main results was published according to Statistics Portugal press releases' calendar. National dissemination occurred on the planned date without delay.
15.1. Comparability - geographical
Geographical comparability is supported by the harmonised definitions, classifications (NACE Rev. 2) and breakdowns specified in the GVC Implementing Act. Methodological guidance from Eurostat ensures a common framework across EU Member States. No national deviations from the European definitions were applied. Minor procedural differences at national level may occur but do not materially affect comparability.
15.2. Comparability - over time
The 2021-2023 cycle is the first official GVC data collection under the European Business Statistics (EBS) Regulation. However, Statistics Portugal has previous experience with voluntary or pilot GVC surveys carried out before the EBS framework. Broad conceptual continuity exists between the earlier exercises and the current official collection, as key definitions, business function categories and geographical breakdowns follow the same methodological foundations. Nevertheless, differences in survey design, sampling approach, questionnaire content or follow-up procedures may limit full comparability with earlier voluntary results. No methodological breaks exist within the 2021-2023 cycle itself.
15.3. Coherence - cross domain
Cross-domain coherence is generally ensured through comparisons with related statistics such as SBS, FATS, TEC and STEC. Differences may arise due to varying reference periods, reporting thresholds (such as the EUR 100 000 criterion) or domain-specific definitions. These discrepancies are limited and do not substantially affect the interpretation of GVC results.
15.4. Coherence - internal
Internal coherence is supported by validation checks that ensure consistency across activity, size class, business function and geographical breakdowns. Logical rules are applied to verify relationships between variables, and follow-up procedures address inconsistencies where necessary. Enterprises reporting international sourcing are expected to appear in the relevant business function or partner breakdowns.
The overall response burden for the GVC data collection is considered manageable. The survey is limited to enterprises with 50 or more persons employed, and several variables can be supported by business register information or pre-filled where available. Burden reduction measures include clear questionnaire design, targeted follow-up and the reuse of administrative data. Internal Statistics Portugal resource use was in line with standard operational requirements for business surveys. The average completion time for the questionnaire was estimated at around 65 minutes.
17.1. Data revision - policy
Statistics Portugal applies a national revision policy that allows for updates to previously transmitted data when significant new or corrected information is identified. Revisions follow the principles set out in national dissemination and quality guidelines and are communicated to Eurostat through established ESS procedures. Because the GVC dataset is collected for a fixed reference period, revision activity is typically limited to the period shortly after the initial transmission.
Further details can be accessed in the revisions policy publication available at Statistics Portugal's website.
17.2. Data revision - practice
In practice, revisions are infrequent and usually concern clarifications or corrections identified during validation or respondent follow-up. These adjustments may relate to detailed classifications such as geographical partner categories or sourcing motivations. All revisions are documented internally and communicated to Eurostat as part of the validation process. A small number of records were revised following additional clarification from respondents. No major changes affecting headline indicators were required.
18.1. Source data
The primary data source is a dedicated survey of enterprises in NACE sections B-N with 50 or more persons employed. The sampling or coverage frame is derived from the national statistical business register, which provides core information on economic activity and size class. Register information may also support validation or reduce respondent burden where appropriate.
To establish the sampling frame, consideration was given to active enterprises common to the universe of the Integrated Business Accounting System (IBAS) (in the first year of the reference period) and the Universe of Structure (in the last year of the reference period), classified in sections B to N of NACE-Rev.2, with 50 or more employees and self-employed persons in the last year of the reference period and which met at least one of the following conditions:
Belonging to multinational enterprise groups;
They are affiliates in Portugal of foreign enterprises (IFATS);
They have engaged in international trade in goods and/or services.
For the purposes of sample size estimation and selection, the sampling frame was stratified by NACE-Rev.2 section and by the following breakdowns of number of employees and self-employed persons:
Breakdown of employees and self-employed persons (EPS)
Number of employees and self-employed persons (NPS)
2
50 ≤ NPS ≤ 99
3
100 ≤ NPS ≤ 249
4
NPS ≥ 250
The sample size was calculated to ensure that the coefficient of variation for the turnover variable did not exceed 15% for each section of NACE-Rev.2.
The distribution of the sample across the strata was carried out in proportion to the square root of the total number employees and self-employed persons. Thus, in stratum h’, the sample size is given by:
being,
nh – Sample size in stratum h
Nh – Universe size in stratum h
NPSh – Total number of persons employed in the universe in stratum h
n – Total sample size
H – Total number of strata (h=1,…, h’ …H)
It was decided that the minimum sample size in each stratum should be 10 enterprises, whenever its size allowed.
For the purposes of sample selection, each enterprise was assigned a random number, generated with a uniform distribution in the range 0 to 1.
Within each stratum, enterprises were ordered in ascending order of that number, and the first nh enterprises were selected, i.e., those corresponding to the smallest nh random numbers.
Sample – the number of enterprises
NACE Rev. 2 sector
Total number of enterprises with 50+ persons employed
B
19
C
5509
D
20
E
31
F
102
G
518
H
113
I
47
J
126
K
6
L
14
M
95
N
124
Total
1 724
Sample – the number of persons employed in the enterprises included in the sample
NACE Rev. 2 sector
Total number of persons employed in enterprises with 50+ persons employed
B
3 483
C
193 705
D
8 503
E
8 831
F
28 964
G
224 919
H
65 489
I
18 790
J
72 186
K
463
L
7 201
M
44 001
N
91 625
Total
763 160
18.2. Frequency of data collection
The GVC data are collected every three years in accordance with Implementing Regulation (EU) 2022/918 of 13 June 2022. No interim or annual data collection is carried out, as the domain is designed to provide structural information for a fixed three-year reference period. The triennial cycle allows sufficient time for preparation, collection, validation and transmission. The most recent data collection covered the reference period 2021-2023 and was carried out once during 2024.
18.3. Data collection
Data collection was carried out through a standalone web survey sent to enterprises in Portugal, with a mandatory response requirement. Follow-up procedures such as automated reminders or targeted contacts are used to improve response rates.
The collection period lasted around three months (Apr-Jul 2024) to allow enterprises sufficient time to complete the questionnaire. Approximately 26% of enterprises required follow-up contacts to clarify or complete their responses.
18.4. Data validation
Validation procedures include automated checks incorporated within the web-questionnaire for completeness, internal consistency, logical coherence and compliance with the definitions and breakdowns specified in the GVC Implementing Act. Manual review is conducted for flagged cases, inconsistencies and outliers. Cross-domain checks compare selected indicators with SBS, FATS, TEC, STEC and business register variables. Validation is performed at both microdata and aggregated levels and incorporates feedback from Eurostat's validation process.
18.5. Data compilation
Data compilation follows Statistics Portugal standard procedures for business surveys.
In grossing-up procedures it is used a weight based on the number of enterprises.
The set of validation rules incorporated into the electronic questionnaire does not allow partial non-responses. No imputation of total non-responses was made, so the disclosure of information was associated with the response rate obtained.
The total estimator for category c of question q in stratum h (t ̂_hqc) is defined by,
where n_(r,h) represents the number of respondents in stratum h (h=1,…,H), y_hqci represents the response of unit i in stratum h to category c of question q (1 if the unit has the characteristic, 0 otherwise) and N_h is the number of units in the population of stratum h.
The estimator of the total for category c of question q (T ̂_qc) is defined by,
The estimator of the total variance is given by:
where s_h^2 is the variance calculated from the sample values for each of the strata.
18.6. Adjustment
No seasonal or trend adjustments are applied, as the GVC dataset refers to structural triennial information. Adjustments are limited to validation-related edits, imputation for missing items and outlier treatment where necessary, following standard procedures for structural business statistics.
No additional comments were identified at this stage. Possible future improvements may include expanded use of administrative sources, increased microdata linking and enhancements to follow-up procedures to reduce item non-response.
Global Value Chains (GVC) comprise the full range of cross-border activities required to bring a product or service from conception through the different production and delivery phases to final consumers.To stay competitive, enterprises increasingly organise their production globally in GVC by breaking up their value chains into smaller parts supplied by a growing number of providers located worldwide. GVC statistics can help measure organisational and spatial patterns in domestic, regional and global value chains, and monitor their effect on employment, wages, value-addition, innovation, skills, firm survival and turnover. From an EU policy perspective, such analysis provides crucial data on the movement of EU jobs to extra-EU countries, dependency on foreign parts of the chain, and the EU's integration in global value chains. Moreover, in the post-COVID-19 world, there are reports of a shortening of GVCs and a de-globalisation trend resulting from the COVID-19 pandemic. Therefore, statistics on GVC are necessary to support policies on trade, job sustainability and economic development.
One of the first efforts to measure the GVC phenomenon in Europe came with the international sourcing (IS) survey in 2007, lauched through a common developed questionnaire used by all participating countries. Since 2007, Eurostat has supported and actively contributed to developing and establishing the IS and GVC surveys which were carried out in 2012, 2018, 2021 and the latest one in 2024, already under the EBS Regulation. These efforts culminated with the international sourcing survey (now renamed GVC survey) being included as official statistics in Regulation (EU) 2019/2152 on European Business Statistics ('the EBS Regulation'). Under the EBS Regulation and, as described in the Regulation (EU) 2022/918 (GVC Implementing act) that was adopted on 13 June 2022, the survey's scope has increased to encompass the GVC arrangements and impact on the EU Member States. Targeted topics may change between consecutive surveys to better capture globalisation trends and policy requirements.The 2024 edition of the survey covered the reference period 2021-2023 and was the first mandatory edition following its official integration into the collection of information on European Business Statistics required under the EBS Regulation.
The GVC dataset contains ten variables defined in Implementing Regulation (EU) 2022/918. These cover:
Business functions:
Number of employees and self-employed persons
GVCs:
Number of enterprises purchasing goods from abroad
Number of enterprises supplying goods abroad
Number of enterprises purchasing services from abroad
Number of enterprises supplying services abroad
International sourcing:
Number of enterprises carrying out international sourcing
Number of jobs created in the enterprise as a result of international sourcing
Number of jobs lost or relocated abroad as a result of international sourcing
Number of enterprises that have carried out or considered carrying out international sourcing
Events impacting GVC arrangements:
Number of active enterprises
For variables (2)-(5), the dataset includes only enterprises that report at least EUR 100 000 in goods or services purchased from or supplied abroad in the final year of the reference period.
All data are provided as absolute values and presented by NACE activity, business function, geographical partner area, size class, motivation and barrier types, and other breakdowns required by the regulation.
As already mentioned, most of the data are collected via a common questionnaire sent to enterprises in each EU country by their NSAs. The following data may be collected or obtained from registers or other statistical or administrative data sources:
The main economic activity of the enterprise at the end of the last year of the reference period, year T;
The number of employees and self-employed persons in the last year of the reference period, year T;
Information about participation in an enterprise group.
In summary, the aim of the International Sourcing and Global Value Chains survey is to produce statistical information on enterprises' economic globalisation practices by collecting information on business functions, international sourcing practices, global value chains and the effects of the international economic situation on those practices.
Name of data collection in Portugal for the reference year 2021-2023: Inquérito ao Sourcing e às Cadeias de Valor Globais 2021-2023
21 November 2025
The GVC questionnaire includes the following modules:
Module 1: Business functions - contains questions on the distribution of employees and self employed persons per business function in the enterprise’s structure;
Module 2: GVC arrangements focuses on the purchasing and supply aspects of international trade in goods and services and tries to measure the GVC trade and some of its characteristics;
Module 3: International sourcing contains questions that help measure international sourcing within and outside the enterprise group, business functions being internationally sourced, and locations of international sourcing and jobs that are relocated abroad or created as a result of international sourcing activity per business function;
Module 4: Motivation and barriers for international sourcing focuses on two key questions: 1) why are enterprises motivated to source internationally, and 2) what barriers are stopping them from sourcing or making it more difficult to do so;
Module 5: Impact of recent events on economic globalisation is a new module that tests a GVC’s resilience to recent global events. All modules could have optional questions or response options.
The statistical unit used for the GVC statistics is the enterprise, as defined in Regulation (EU) 2019/2152 of 27 November 2019 on European business statistics and the Business Register Regulation (EC) No 177/2008 of 20 February 2008.
In Portugal, the reporting unit considered in the GVC 2021-2023 was the legal unit and the statistical unit considered was the enterprise (sampling at enterprise level and data collection at legal unit level).
The target population of GVC statistics for the reference period 2021-2023 consists of all market-producing enterprises in NACE Rev.2 sections B to N, with 50 or more employees and self-employed persons in the final year of the reference period. For variables (2)-(5), only enterprises reporting at least EUR 100 000 of goods or services purchased from or supplied abroad are included, in line with the Annex of Implementing Regulation (EU) 2022/918 of 13 June 2022.
NACE Rev. 2 sector
Total number of enterprises with 50+ persons employed
B
23
C
2 452
D
20
E
76
F
510
G
1 050
H
355
I
456
J
396
K
6
L
23
M
328
N
408
Total
6 103
NACE Rev. 2 sector
Total number of persons employed in enterprises with 50+ persons employed
B
3 745
C
390 504
D
8 503
E
17 057
F
76 513
G
271 597
H
90 645
I
74 320
J
103 907
K
463
L
2 774
M
69 179
N
220 603
Total
1 329 810
The reference area is the national economic territory of Portugal (Continente, Região Autónoma dos Açores and Região Autónoma da Madeira), as defined in Regulation (EU) 2019/2152 of 27 November 2019 for European business statistics. Units located within the national territory and covered by national statistical legislation are included.
The reference period for the GVC statistics is 2021-2023, in accordance with Implementing Regulation (EU) 2022/918 of 13 June 2022. Variables cover activities that may have occurred during this three-year period.
Variables (1)-(5) refer specifically to the final year of the period (2023).
Variables (6)-(10) cover actions that took place at any time between 1 January 2021 and 31 December 2023.
Overall accuracy is assessed using checks on coverage, internal coherence and consistency with related business statistics. Most units in the target population provided usable data, and validation procedures reduced the impact of inconsistent responses. Some uncertainty remains for detailed variables, particularly those requiring subjective assessments such as sourcing motivations and barriers.
All variables in the GVC dataset are compiled and transmitted in absolute values, in accordance with the measurement unit specified in Implementing Regulation (EU) 2022/918 of 13 June 2022. No percentages, indexes, ratios or other derived units are transmitted to Eurostat. This unit applies uniformly to all variables and all breakdowns required by the regulation.
Data compilation follows Statistics Portugal standard procedures for business surveys.
In grossing-up procedures it is used a weight based on the number of enterprises.
The set of validation rules incorporated into the electronic questionnaire does not allow partial non-responses. No imputation of total non-responses was made, so the disclosure of information was associated with the response rate obtained.
The total estimator for category c of question q in stratum h (t ̂_hqc) is defined by,
where n_(r,h) represents the number of respondents in stratum h (h=1,…,H), y_hqci represents the response of unit i in stratum h to category c of question q (1 if the unit has the characteristic, 0 otherwise) and N_h is the number of units in the population of stratum h.
The estimator of the total for category c of question q (T ̂_qc) is defined by,
The estimator of the total variance is given by:
where s_h^2 is the variance calculated from the sample values for each of the strata.
The primary data source is a dedicated survey of enterprises in NACE sections B-N with 50 or more persons employed. The sampling or coverage frame is derived from the national statistical business register, which provides core information on economic activity and size class. Register information may also support validation or reduce respondent burden where appropriate.
To establish the sampling frame, consideration was given to active enterprises common to the universe of the Integrated Business Accounting System (IBAS) (in the first year of the reference period) and the Universe of Structure (in the last year of the reference period), classified in sections B to N of NACE-Rev.2, with 50 or more employees and self-employed persons in the last year of the reference period and which met at least one of the following conditions:
Belonging to multinational enterprise groups;
They are affiliates in Portugal of foreign enterprises (IFATS);
They have engaged in international trade in goods and/or services.
For the purposes of sample size estimation and selection, the sampling frame was stratified by NACE-Rev.2 section and by the following breakdowns of number of employees and self-employed persons:
Breakdown of employees and self-employed persons (EPS)
Number of employees and self-employed persons (NPS)
2
50 ≤ NPS ≤ 99
3
100 ≤ NPS ≤ 249
4
NPS ≥ 250
The sample size was calculated to ensure that the coefficient of variation for the turnover variable did not exceed 15% for each section of NACE-Rev.2.
The distribution of the sample across the strata was carried out in proportion to the square root of the total number employees and self-employed persons. Thus, in stratum h’, the sample size is given by:
being,
nh – Sample size in stratum h
Nh – Universe size in stratum h
NPSh – Total number of persons employed in the universe in stratum h
n – Total sample size
H – Total number of strata (h=1,…, h’ …H)
It was decided that the minimum sample size in each stratum should be 10 enterprises, whenever its size allowed.
For the purposes of sample selection, each enterprise was assigned a random number, generated with a uniform distribution in the range 0 to 1.
Within each stratum, enterprises were ordered in ascending order of that number, and the first nh enterprises were selected, i.e., those corresponding to the smallest nh random numbers.
Sample – the number of enterprises
NACE Rev. 2 sector
Total number of enterprises with 50+ persons employed
B
19
C
5509
D
20
E
31
F
102
G
518
H
113
I
47
J
126
K
6
L
14
M
95
N
124
Total
1 724
Sample – the number of persons employed in the enterprises included in the sample
NACE Rev. 2 sector
Total number of persons employed in enterprises with 50+ persons employed
B
3 483
C
193 705
D
8 503
E
8 831
F
28 964
G
224 919
H
65 489
I
18 790
J
72 186
K
463
L
7 201
M
44 001
N
91 625
Total
763 160
GVC statistics are collected, compiled and transmitted every three years in accordance with Implementing Regulation (EU) 2022/918 of 13 June 2022.
National dissemination, where applicable, follows the same triennial cycle and usually takes place before the transmission of data and metadata to Eurostat.
Data and metadata were transmitted to Eurostat within the legal deadline of T+21 months. Processing stages, including data collection, validation and preparation for transmission, were completed according to the national timetable. The transmission of data from Portugal took place approximately 3 months before the deadline.
Geographical comparability is supported by the harmonised definitions, classifications (NACE Rev. 2) and breakdowns specified in the GVC Implementing Act. Methodological guidance from Eurostat ensures a common framework across EU Member States. No national deviations from the European definitions were applied. Minor procedural differences at national level may occur but do not materially affect comparability.
The 2021-2023 cycle is the first official GVC data collection under the European Business Statistics (EBS) Regulation. However, Statistics Portugal has previous experience with voluntary or pilot GVC surveys carried out before the EBS framework. Broad conceptual continuity exists between the earlier exercises and the current official collection, as key definitions, business function categories and geographical breakdowns follow the same methodological foundations. Nevertheless, differences in survey design, sampling approach, questionnaire content or follow-up procedures may limit full comparability with earlier voluntary results. No methodological breaks exist within the 2021-2023 cycle itself.
