7. Quality and methodology

Basic quality information

The International trade in services Quality and Methodology Information report contains important information on:

the strengths and limitations of these data and how they compare with related data

users and uses of these data

how the output was created

the quality of the output including the accuracy of data

Accuracy

Sampling error is the error caused by observing a sample instead of the whole population. While each sample is designed to produce the “best” estimate of the true population value, a number of equal-sized samples covering the population would generally produce varying population estimates. Sampling error is affected by a number of factors including sample size.

Sample surveys are used instead of censuses, because the process would be too lengthy and costly to be viable. Standard errors are an estimate of the sampling error and provide a measure of the precision of the estimate. A low standard error indicates a precise estimate. To aid comparison, the standard error is also expressed as a percentage of the total value. This quantity is called the coefficient of variation and it allows the standard errors to be put into context.

In addition to sampling errors, there is the potential for non-sampling error that cannot be easily quantified. For example, undetected deficiencies may occur in the survey register and errors may be made by the contributors when completing the survey questionnaires.

Table 1: Standard errors, 2017 Exports Imports Industries Estimate

(£ million) Standard

error

(£ million) Relative

Standard

error (%) Estimate

(£ million) Standard

error

(£ million) Relative

Standard

error (%) Total ITIS 162,141 1,873 1 78,731 980 1 Manufacturing 16,299 163 1 11,652 100 1 Wholesale and Retail 16,687 196 1 6,471 237 4 Information and

Communication 42,681 966 2 25,080 565 2 Professional, Scientific

and Technical 44,956 984 2 19,049 605 3 Administrative and

Support Services 9,746 753 8 3,799 317 8 Arts, Entertainment

and Recreation 5,156 26 1 1,845 22 1 Download this table Table 1: Standard errors, 2017 .xls .csv

Non-response bias is a potential issue for all statistical surveys. Non-response bias occurs where the answers of respondents may have differed from the potential answers of non-responders. The risk of non-response bias is minimised by efforts to maximise response rates. Estimation techniques can attempt to correct for any bias that might be present. Despite this, it is not easy, on any survey, to quantify the extent to which non-response bias remains a problem. However, there is no evidence to suggest that non-response bias presents a particular issue for the International Trade in Services (ITIS) survey.

Imputation methods are used to estimate values for all businesses in the sample that did not return data. Estimation methods are used to estimate values for all non-sampled businesses within the population to produce an overall estimate for the population.

The response rate for the 2017 annual survey is shown in Table 2.

Table 2: International trade in services response rates, 2017

UK 2017 Results Sample size 16,452 Forms with response 14,251 Forms non response 2,201 Overall response rate (%) 87 Download this table Table 2: International trade in services response rates, 2017 .xls .csv

Notes to tables

The tables present ITIS estimates through a variety of formats. Some tables compare figures over several years but the majority provide the most recent geographic information by industry or product. The tables provide information in as much detail as possible without disclosing the details of any individual companies. It is important to note that within the geographical tables, amounts are shown against the geographical area from which they were received, irrespective of where they were first earned.

The European Free Trade Association (EFTA) comprises Iceland, Liechtenstein, Norway and Switzerland. The sum of constituent items in tables may not always agree exactly with the totals shown due to rounding. The following symbols have been used throughout:

“..” is used for figures suppressed to avoid disclosure of information relating to individual enterprises

“–” is used for nil or less than half the final digit shown

Values shown are in current prices, which refer to the price at which the services were either bought or sold in the market.

Guidance on interpreting international trade in services statistics

The ITIS survey collects data relating to the amounts spent on both the imports and exports of UK businesses and collects geographical information as to where the services have either been imported from or exported to.

Types of transactions covered

Product

The statistical output from the ITIS survey covers the value of transactions between the UK and residents in other countries in respect of 52 products. The 2013 ITIS questionnaire was revised in accordance with new international regulations. A breakdown showing the services products collected up to 2012 and from 2013 onwards can be found in Table 3.

Table 3: International Trade in Services (ITIS) questionnaire codes, 2012 to 2013 onwards, UK Questionnaire breakdown

up to and including 2012 Questionnaire breakdown 2013 onward 01. Agricultural Services 01. Agricultural, forestry

and fishing services 02. Mining Services 02. Mining and oil gas

extraction services 03. Waste treatment and depollution 03. Waste treatment and

depollution services 04. Other on-site processing services 04. Manufacturing services on

goods owned by others 05. Maintenance and repair services 05. Accountancy, auditing, bookkeeping and

tax consulting services 06. Accountancy, auditing, bookkeeping

and tax consulting services 06. Advertising 07. Advertising, market research and

public opinion polling services 07. Management consulting 08. Business management and management

consulting services 08. Public relations services 09. Public relations services 09. Recruitment and training 10. Recuritment services 10. Other business management

services (see 7) 08. Business management and management

consulting services 11. Legal services 11. Legal services 12. Market research and public opinion

polling (see 6) 07. Advertising, market research and

public opinion polling services 13. Operational leasing services 12. Operating leasing services 14. Procurement 13. Procurement services 15. Property management 14. Property management services 16. Research & Development 16. Provision of R&D services 17. Provision of product development

and testing activities 17. Services between related enterprises 51. Transactions between related

businesses not included elsewhere 18. Other business and professional

services 15. Other business and professional services 19. Postal and courier services 21. Postal and courier services 20. Telecommunication services 22. Telecommunication services 21. Computer services 23. Computer services 22. News agency services 25. News agency services 23. Publishing services 24. Publishing services 24. Other information provision

services 26. Information services 25. Construction in the UK 27. Construction in the UK 26. Construction outside the UK 28. Construction outside the UK 27. Financial services 29. Financial services 28. Auxilliary services 36. Auxilliary services 29. Claims 32. Freight insurance claims 30. Premiums 33. Freight insurance premiums 31. Claims 30. Life insurance claims 32. Premiums 31. Life insurance premiums 33. Claims Removed 34. Premiums Removed 35. Claims 34. Other direct insurance claims 36. Premiums 35. Other direct insurance premiums No equivalent 37. Pension service receipts No equivalent 38. Pension service charges No equivalent 39. Standardised guarantee service claims No equivalent 40. standardised guarantee service premiums 37. Merchanting 41. Merchanting 38. Other trade-related

services 42. Other trade-related services 39. Audio-visual and related

services 43. Audio-visual and related services 40. Health services 44. Health services 41. Training and educational

services 45. Training and educational services 42. Other personal, cultural

and recreational services 46. Heritage and recretional services 43. Use of franchise and similar

rights fees 18b. Charges or payments for the use of the above,

but without transfer of ownership 44. Other royalties and license fees 19b. Charges or payments for the use of the above,

but without transfer of ownership 45. Purchases ans sales of franchises

and similar rights 20b. Charges or payments for the use of the above,

but without transfer of ownership 46. Purchases ans sales of other

royalties and licenses 18a. Outright sales and purchases of the above,

resulting in transfer of ownership 19a. Outright sales and purchases of the above,

resulting in transfer of ownership 20a. Outright sales and purchases of the above,

resulting in transfer of ownership 42. Other personal, cultural

and recreational services 47. Social, domestic and other

personal services 47.Architectural 48. Architectural services 48. Engineering 49. Engineering services 49.Surveying (see 50) 50. Scientific and other technical

services (including surveying) 50. Other technical services (see 49) 51. Other trade in services 52. Other trade in services Download this table Table 3: International Trade in Services (ITIS) questionnaire codes, 2012 to 2013 onwards, UK .xls .csv

Industry

The industry analysis enables estimation for the total international transactions in services by economic classification for well-defined areas of the economy using Standard Industrial Classification (SIC) information. Data from 2009 in this publication have been published in SIC 2007 classification, which is an internationally-recognised classification. This provides a framework for the collection, tabulation, presentation and analysis of data about economic activities. Prior to 2009, SIC 2003 classification was used.

Geographical

Both industry and product information are analysed geographically. The tables within this publication provide geographical breakdowns of countries to which UK services are exported to and from where services are imported to the UK. The definitions of the geographical groupings used in the tables can be found in the International trade in services Quality and Methodology Information report.

Earnings from third country trade, that is, from arranging the sale of goods between two countries other than the UK and where the goods never physically enter the UK are included. This activity is known as merchanting. Earnings from commodity trading are also included. As with merchanting, the service element is the profit or loss.

Types of transactions not covered

The purpose of the ITIS survey is to record international transactions that impact on the UK’s Balance of Payments, hence companies are asked to exclude from their earnings trade expenses such as the cost of services purchased and consumed abroad. Trade in services exports or imports that are invoices for the export or import of goods are excluded as they are already counted in the estimates for trade in goods.

The ITIS survey currently selects for the whole of the economy, with a number of exceptions, such as:

travel

transport

banking and other financial institutions

higher education

charities

most activities within the legal profession

Coverage

The figures for the European Union (EU) relate to the other 27 member states of the EU from 2013 onwards. Trade with EU institutions is also included in the EU totals and excluded from the international organisations totals. Please note that all tables in this publication only include data collected via the ITIS and Annual Business Survey surveys.

The film and television (FTV) industries are included in the published data from 2009 onwards. For 2008, FTV figures were collected via a separate survey and data were published in the International transactions of the UK film and television industries statistical bulletin 2008.

The ITIS survey is just one component of trade in services (TIS) estimates. Data for TIS in this report are consistent with the UK Balance of Payments, which can be found in Pink Book Chapter 3.

By analogy with trade in goods we refer to the type of service traded as a “product analysis” – the products being consistent with the sixth edition of the Balance of Payments Manual. The second type of analysis is referred to as the “industry analysis” – covering well-defined areas of the economy.

Both types of tables, industry and product, have been analysed on a geographical basis by showing the countries to which services are exported and from where they are imported. Both of these types of analyses are preceded by geographical analysis of imports and exports of total international trade in services.

The industry analysis allows us to estimate the total international transactions in services for well-defined areas of the economy. It also tells us the exporting or importing country in relation to the UK.

Discussing business statistics online

There is a Business and Trade Statistics community on the StatsUserNet website. StatsUserNet is the Royal Statistical Society’s interactive site for users of official statistics. The community objectives are to promote dialogue and share information between users and producers of official business and trade statistics about the structure, content and performance of businesses within the UK. Anyone can join the discussions by registering via either of the previous links.