Index of Services, UK: July 2015

Monthly movements in output for the services industries: distribution, hotels and restaurants; transport, storage and communication; business services and finance; and government and other services.

This is not the latest release. View latest release

29 November 2016

Following a quality review, a processing error has been identified in the compilation of the estimates for the rail transport industry (49.1-2), which affects the period Quarter 1 1997 to Quarter 2 2016. In line with the National Accounts revision policy, this error will be corrected in the Index of Services and Quarterly National Accounts due for publication on 23rd December 2016 for data from Quarter 1 2015 and in the Blue Book 2017 consistent releases for data prior to this period. The average impact over this period on quarter-on-quarter Index of Services and GDP growth is 0.00%. This processing error does not impact quarter on quarter growth into Quarter 3 2016.

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Contact:
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Release date:
30 September 2015

Next release:
27 October 2015

1. Main points

  • This release of data is consistent with the Quarterly National Accounts released on 30 September 2015 and data used for Blue Book 2015 due for release on 30 October 2015. The last year of chain-linked weights has been updated from 2011 to 2012 and the reference year has also changed from 2011 to 2012. In line with normal practice for this annual update, seasonal models have also been reviewed and amended where necessary

  • The Index of Services is estimated to have increased by 2.8% in July 2015 compared with July 2014. All of the 4 main components of the services industries increased in the most recent month compared with the same month a year ago

  • The largest contributions came from: business services and finance, which contributed 1.2 percentage points to total growth; and distribution, hotels and restaurants, which contributed 0.8 percentage points to total growth

  • The latest Index of Services estimates show that output increased by 0.2% between June 2015 and July 2015, following an increase of 0.6% between May 2015 and June 2015

  • The Index of Services increased by 0.6% in Quarter 2 (Apr to June) 2015 compared with Quarter 1 (Jan to Mar) 2015

  • This figure has been revised down by 0.1 percentage points from that included in the Second Estimate of Gross Domestic Product (GDP), published on 28 August 2015 and is consistent with the Quarterly National Accounts published on 30 September 2015

  • The figures within this release are estimates and are on a seasonally adjusted basis. The earliest period open for revision in this release is January 1997

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2. Understanding the Index of Services (IoS)

About the IoS

The monthly IoS provides a timely indicator of growth in the output of the services industries. The IoS is an important economic indicator and shares exactly the same industry coverage as the corresponding quarterly series within UK gross domestic product (GDP). The primary purpose of the IoS is to produce a short-term measure of the output of the services industries within the UK economy and show the monthly movements in the gross value added (GVA) of the service industries 2007 Standard Industrial Classification (SIC 2007) sections G to T).

The 4 main components of the services industries are:

  • distribution, hotels and restaurants

  • transport, storage and communication

  • business services and finance

  • government and other services

The IoS is the largest contributor to the output approach to the measurement of GDP, accounting for 78.6% of UK GDP in 2012.

All data in this bulletin are seasonally adjusted estimates and have had the effect of price changes removed (in other words, the data are deflated). Further information on some of the main concepts (including seasonal adjustment and deflation) underlying the estimates can be found in background note 12.

The quality of the IoS

The IoS is published around 8 weeks after the end of the reference month. There is no simple way of measuring the accuracy of the IoS, that is, the extent to which the estimate measures the underlying “true” value of the output growth (of the services industries) in the UK for a particular period. All estimates, by definition, are subject to statistical uncertainty and for many well-established statistics the Office for National Statistics (ONS) measures and publishes the sampling error associated with the estimate, using this as an indicator of accuracy. However, as IoS is constructed from a wide variety of data sources, some of which are not based on random samples, we don’t publish a measure of the sampling error associated with the IoS.

Reliability is one dimension of measuring accuracy, using evidence from analyses of revisions to assess the closeness of early estimates to subsequent estimated values. Revisions are an inevitable consequence of the trade-off between timeliness and accuracy. Figures for the most recent months are provisional and subject to revision in light of:

  • late responses to surveys and administrative sources

  • forecasts being replaced by actual data

  • revisions to seasonal adjustment factors, which are re-estimated every month and reviewed annually

Revisions to the IoS are typically small (around 0.1 to 0.2 percentage points), with the frequency of upward and downward revisions broadly equal. More information on the most recent revisions analysis can be found in the component analysis section and in background note 18.

It should be noted that care should be taken when using the month-on-month growth rates, due to their volatility (background note 11).

Further information on the quality of the IoS is available in the Quality of the IoS (29 Kb Pdf) report on the Index of Services Methods page on our website. It should be noted that as part of the IoS industry review process, we are continually working on methodological changes to improve the accuracy of the IoS.

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3. Main information

The Index of Services (IoS) measures the quantity of output from all UK services industries, which account for more than three-quarters of the output approach to the measurement of gross domestic product. Index values are presently referenced to 2012 so that the average for 2012 is equal to 100. Therefore, an index value of 110 would indicate that output is 10% higher than the average for 2012.

As seen in Figure 1, the IoS increased by 2.8% in July 2015 compared with July 2014. In order of their contribution to growth (listed in reference table IOS1):

  1. business services and finance increased by 3.0%

  2. distribution, hotels and restaurants increased by 4.6%

  3. transport, storage and communication increased by 5.6%

  4. government and other services increased by 0.2%

Further detail on these movements can be found in the component analysis section.

Between June 2015 and July 2015, as seen in Figure 2, the IoS increased by 0.2%.

Out of the 4 main components of the services industries, 2 increased in the most recent month compared with the previous month. In order of their contribution to growth (listed in reference table IOS1):

  1. transport, storage and communication increased by 0.8%

  2. business services and finance increased by 0.1%

Both the business services and finance component and the distribution, hotels and restaurants component remained flat with a change of 0.0%.

More detail on individual components can be found in the IOSCOMP tables in the data section of this bulletin. The tables also provide information on the growth for the 3 months ending in July 2015 compared with the previous 3 months and compared with the 3 months ending July 2014.

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4. Economic background

Total services grew by 2.7% between Quarter 2 (Apr to June) 2014 and Quarter 2 (Apr to June) 2015, and by 0.6% between Quarter 1 (Jan to Mar) 2015 and Quarter 2 (Apr to June) 2015. This is compared with growth rates of 2.4% and 0.7% respectively for the economy as a whole.

Since 1997, the services industries have grown at a faster rate than all other headline industries. While GDP has grown at a compound average annual growth rate of 2.0% since 1997, services has grown at a compound average growth rate of 2.8% per year (more information can be found in Quarterly National Accounts, Quarter 2 (Apr to June) 2015). This has led to a continuing re-orientation of the economy towards services, despite productivity in the services industries rising more slowly than in the production industries (and manufacturing in particular) since 1997 (more information can be found in Labour Productivity, Quarter 1 (Jan to Mar) 2015). The higher output growth, therefore, reflects the increasing share of the labour force employed in services, which has grown from 73% to 79% between 1997 and 2014 (Labour Market Statistics, September 2015, reference table EMP13).

In addition to strong long-run growth, the services industries were also less affected by the downturn in 2008 than other industries, such as production and construction, and subsequently recovered more quickly. Relatively strong growth in the services industries has provided the largest contribution to the recovery in the whole economy and has been the only industry grouping to have surpassed its pre-downturn peak levels (more information can be found in Quarterly National Accounts, Quarter 2 (Apr to June) 2015).

Even though the entire services industries have been performing better than all other headline industries, the growth within the services’ sub-components has been quite varied. Figure 3 shows that between 1997 and 2014, transport, storage and communications, and business services and finance grew faster than the entire services industries at compound average growth rates of 3.7% and 3.8% per annum respectively, while the entire services industries grew at a compound average growth rate of 2.8% per year over the same period. However, government and other services, and distribution, hotels and restaurants grew at a slower rate than the entire services industries (1.7% and 1.8% per annum respectively) between 1997 and 2014.

The economic downturn, Quarter 1 (Jan to Mar) 2008 to Quarter 2 (Apr to June) 2009, impacted the 4 sub-components of the entire services industries to a different degree. Distribution, hotels and restaurants, and transport, storage and communications were affected the most, with their output falling by 9.1% and 7.5% respectively, while the output of the entire services industries contracted by 4.1% over the same period. Business services and finance and government and other services were impacted less severely, with their output contracting by 3.5% and 0.1% respectively.

Business services and finance, and transport, storage and communications recovered very strongly following the economic downturn and in Quarter 2 (Apr to June) 2015 they were 13.9% and 10.0% above their respective values in Quarter 1 (Jan to Mar) 2008. The recovery of distribution, hotels and restaurants was also quite strong and in Quarter 2 (Apr to June) 2015 output was 8.9% above pre-downturn levels. However, the recovery of the government and other services industries was more modest, with output currently being 6.5% above Quarter 1 (Jan to Mar) 2008 values.

Figure 4 shows the share of gross value added accounted for by services in the UK and a selection of other major economies (more information on data for France, Germany, Italy, Japan and the USA can be found on the Organisation for Economic Co-operation and Development (OECD) website). In 1997 the share of gross value added (GVA) accounted for by services in the UK was just under 70% of nominal GVA, around the middle of the range relative to the other economies shown. By 2013, the UK had become relatively more reliant on services, as its share rose to almost 80% of nominal GVA.

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5. GDP impact and components

With a weight of 78.6%, the services industries are the largest industrial grouping in the output approach to measuring GDP. The releases for the short-term economic indicators that feed directly into the output approach to measuring GDP include a table detailing growth in the 4 main industrial groupings (Table 2). This will aid understanding of the relationship between the individual short-term releases and GDP output.

In Quarter 2 (Apr to June) 2015, GDP was estimated to have increased by 0.7% compared with the previous quarter. The contribution an industry grouping makes to the GDP quarterly growth is dependent on the quarterly change in that industry grouping and its weight within the output approach to measuring GDP.

Monthly estimates are produced for each industrial grouping except agriculture. The July 2015 estimates for production and construction were published on 9 September 2015 and 11 September 2015 respectively. The Quarterly National Accounts for Quarter 2 (Apr to June) 2015 was published on 30 September 2015 alongside this bulletin.

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6. Component analysis

Distribution, hotels and restaurants

The index of distribution, hotels and restaurants increased by 4.6% in July 2015 compared with July 2014, following an increase of 4.8% in June 2015 compared with the same month a year earlier. The main contributors to the increase were: retail trade, except of motor vehicles and motorcycles, which rose by 3.9%; wholesale and retail trade and repair of motor vehicles and motorcycles, which rose by 9.4%; and accommodation, which rose by 15.0%.

Transport, storage and communication

The index of transport, storage and communication increased by 5.6% in July 2015 compared with July 2014, following an increase of 5.3% in June 2015 compared with the same month a year earlier. The main contributors to the increase were: publishing, audiovisual and broadcasting activities, which rose by 17.8%; computer programming, consultancy and related activities, which rose by 7.6%; and telecommunications, which rose by 2.9%.

Business services and finance

The index of business services and finance increased by 3.0% in July 2015 compared with July 2014, following an increase of 3.4% in June 2015 compared with the same month a year earlier. The main contributors to the increase were: other professional service activities, which rose by 5.4%; administrative and support services activities, which rose by 4.9%; and real estate activities, which rose by 1.7%.

Government and other services

The index of government and other services increased by 0.2% in July 2015 compared with July 2014, following an increase of 0.4% in June 2015 compared with the same month a year earlier. The main contributors to the increase were: human health and social work activities, which rose by 1.7%; other service activities, which rose by 1.4%; and education, which rose by 0.3%.

Revisions

The Index of Services (IoS) follows the National Accounts Revisions policy (41.6 Kb Pdf) . Revisions are caused by a number of factors including, but not limited to:

  • revisions to source data due to late responses

  • actual data replacing forecast data

  • revisions to seasonal factors that are re-estimated every period

More information on IoS revisions is available on the Index of Services Methods page.

We produce revisions triangles of services growth to provide users with one indication of the reliability of this main indicator. Statistical tests are performed on the average revision to test if it is statistically significantly different to 0. Further information can be found in background note 15.

In this release of data, the earliest period open to revision is January 1997 as this dataset contains the annual updates which will be included in the Blue Book 2015, published in October 2015.

There are numerous sources of revision which will affect services in the Blue Book 2015 publication, including but not limited to:

  • updates to the annual gross value added weights

  • updated source data

  • improved statistical methods

  • alignment to GDP annual growths

As is common for the first Index of Services publication following the annual updates, there are more and larger revisions than an ordinary publication.

Further information on improvements to the output approach to measuring GDP and revisions can be found in the GDP Output Improvement Report.

Further detail on the revisions to the IoS components can be found in the RIOS1 tables in the data section of this publication.

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7. Industry spotlight: Activities of head offices; management consultancy activities

According to the UK Standard Industrial Classification 2007 (SIC2007), industry 70 includes the activities of head office and management consultancy activities. This industry covers the provision of advice and assistance to businesses and other organisations on management issues, financial planning and budgeting, marketing objectives and policies, human resource policies, practices and planning, and production scheduling and control planning. Further to this, it also includes the overseeing and managing of other units of the same company or enterprise, that is the activities of head offices.

Industry 70 is divided into 2 divisions: activities of head office (division 70.1) and management consultancy activities (division 70.2) which accounts for the majority of turnover for the industry (91.7%) (Annual Business Survey). In 2013, this industry generated £54.5 billion of turnover, which represented 23.9% of the turnover of the professional, scientific and technical activities section (section M) (Annual Business Survey). Moreover, the share of total output attributed to industry 70 increased from 0.4% in 1997 to 1.2% in 2013, signalling a strong growth rate relative to the rest of the economy (Quarterly National Accounts, Quarter 2 (Apr to June) 2015).

Industry 70 has performed better than the entire services industries since 1997. Between Quarter 1 (Jan to Mar) 1997 and Quarter 1 (Jan to Mar) 2008 this industry experienced relatively strong continuous growth, rising at a compound growth rate of 3.5% per quarter while the services industries grew at a compound growth rate of 0.9% per quarter over the same period. During the economic downturn, Quarter 1 (Jan to Mar) 2008 to Quarter 2 (Apr to June) 2009, the output of the entire services industries and industry 70 contracted at different times and to different extents. Services started to contract in Quarter 2 (Apr to June) 2008, and output fell by 4.1% between the industries peak in Quarter 1 (Jan to Mar) 2008 and the industries trough in Quarter 2 (Apr to June) 2009. However, industry 70 started to contract 3 quarters later (Quarter 1 (Jan to Mar) 2009) and output decreased by 23.9% between the industry’s peak in Quarter 4 (Oct to Dec) 2008 and its trough in Quarter 4 (Oct to Dec) 2009.

Industry 70 and the services industries recovered strongly following their respective periods of contraction. The entire services industries surpassed its pre-downturn peak by Quarter 1 (Jan to Mar) 2012 while industry 70 did not recover to its pre-contraction peak until Quarter 2 (Apr to June) 2013. By Quarter 2 (Apr to June) 2015, industry 70 and the entire services industries were 16.9% and 10.2% above their respective peaks.

Between 2009 and 2014, the total number of employees in industry 70 increased by 45.5%, from 494,200 employees to 719,100 employees (Business register and employment survey (BRES)). This increase reflected rises in the number of both full-time and part-time employees. The growth in the number of employees working part-time and full-time was roughly the same at 45.9% and 45.4%, respectively (Business register and employment survey (BRES)). The broad trend of the number of part-time and full-time employees growing at a similar rate is consistent with the behaviour of the labour market as a whole between 2009 and 2014, where the number of part-time employees grew by 3.9% while the number of full-time employees grew by 3.2% (for more information, please visit Labour Market Statistics, September 2015).

As seen in Figure 7, in 2014 the vast majority (98.0%) of those working in industry 70 were employed by the private sector. Between 2009 and 2014, the number of employees working in the private sector in this industry increased by 226,100, while it decreased by 1,300 in the public sector over the same period. The decrease in the total number of employees working in the public sector in this industry was driven by a fall in full time employees by 1,600 between 2009 and 2014. This was partly offset by a 300 rise in the number of part time employees working in the public sector over the same period (for more information, please visit Business register and employment survey (BRES)).

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8 .Background notes

  1. What’s new

    Blue Book 2015

    The Index of Services (IoS) for July 2015 published on 30 September 2015 includes revisions back to 1997. This will be in line with the open revision period for the 2015 Blue Book publication in October 2015. The estimates will also be consistent with the Quarterly National Accounts published on 30 September 2015.

    These annual changes will include updating the reference year from 2011=100 to 2012=100, along with adding an additional year of chain-linking weights for 2012. As part of the annual GDP balancing process annual adjustments will also be made to the services sector to maintain coherence with the balanced GDP figures. ONS has developed an automatic function for assigning the annual adjustments to gross value added. This is designed to be as faithful as possible to the quarterly paths whilst adjusting the overall annual growth rate.

  2. Continuous improvement of GDP

    The GDP Output Improvement Report, published on 30 September 2015, provides a detailed update of the implementation of improvements for Blue Book 2015, progress on industry reviews and wider cross-cutting improvements, a comprehensive timetable for the industry review project, and progress on experimental statistics.

  3. Experimental statistics

    The Index of Services achieved National Statistic status in 2007 due at least in part to a series of industry reviews which underpinned short-term estimates. However, a number of low-level industries remained experimental statistics when the programme of industry reviews paused in 2008 to focus on the transition to SIC2007, improved deflator methodology, and the implementation of a new IT platform.

    In 2011, IoS moved to SIC2007 and a reappraisal of the experimental industries was made using detailed comments from methodologists who quality assured the progress of IoS towards the National Statistics label. This review was published in August 2012 (249.1 Kb Pdf) and outlined the 17 industries which remained experimental. A review of the 17 industries has taken place by experts in the business area against the Code of Practice for Official Statistics and, in noting the original comments we are clear that the issues and requirements have been addressed where appropriate, further details can be found in the latest GDP Output Improvement Report. Agreement has been given by the Director General for Economic Statistics to officially move these Experimental Statistics to Official Statistics.

  4. VAT project update

    An article titled “Feasibility study into the use of HMRC turnover data within Short-term Output Indicators and National Accounts” has been published (14 August 2015). The project is exploring ways in which HM Revenue & Customs (HMRC) administrative data could be used to quality assure, supplement or replace the current turnover-based ONS surveys. This article is the first of a series of planned articles into this work.

  5. What do you think?

    As a user of our statistics we would welcome your feedback on this publication. If you would like to get in touch please contact us via email: ios.enquiries@ons.gov.uk.

  6. Special events

    We maintain a list of candidate special events in the Special Events Calendar. As explained in our Special Events policy, it is not possible to separate the effects of special events from other changes in the series.

  7. Understanding the data

    Short guide to the Index of Services

    The Index of Services shows the monthly movements in the gross value added (GVA) of the service industries (2007 Standard Industrial Classification (SIC 2007) sections G to T). These industries account for around 79% of gross domestic product (GDP) in 2012. The index is estimated using the same data sources and national accounts methodology as the quarterly estimate of services industries’ gross value added within the output approach to measuring GDP (GDP (O)). These consist of the distribution, hotels and restaurant industries (SIC 2007 sections G and I); transport, storage and communication (sections H and J); business services and finance (sections K to N); and government and other services (sections O to T).

  8. International comparison

    International comparison with the IoS is difficult, as most comparable economies don’t produce equivalent estimates. Eurostat turnover in services estimates are not comparable with the IoS, as they exclude the wholesale and retail trade; furthermore, most of the estimates are only available quarterly. The USA also produces services output estimates, but only on a quarterly basis, with a 4 month lag time. Japan has a direct equivalent of the IoS, but the estimates are not seasonally adjusted. The closest equivalent estimates are from Canada, which produces a monthly output estimate of GDP with a breakdown by industry (including an aggregate for services). There are also comparable quarterly estimates from Sweden and Ireland.

  9. Short guide to national accounts

    The national accounts provide an integrated description of all economic activity within the economic territory of the UK, including activity involving both domestic units (that is, individuals and institutions resident in the UK) and external units (those resident in other countries). In addition to being comprehensive, the accounts are fully integrated and internally consistent. More information can be found in UK national accounts: a short guide (105.5 Kb Pdf) .

  10. How our statistics explain the economy

    The IoS is mentioned in an interactive version of 14 ways ONS statistics help you understand the economy, which was released on our website on 27 June 2014, alongside Quarterly National Accounts for Quarter 1 (Jan to Mar) 2014.

  11. Interpreting the data

    Some monthly data are volatile. When looking at growth rates, the headline IoS figures focus on the percentage change between the most recent month-on-a-year earlier and the most recent 3 months-on-a-year earlier.

    The monthly Index of Services statistical bulletin is usually published on the same days as the Gross Domestic Product Preliminary Estimate statistical bulletin, the Second Estimate of Gross Domestic Product statistical bulletin or the Quarterly National Accounts statistical bulletin.

    The data for the IoS in this statistical bulletin are generally consistent with the Quarterly National Accounts for Quarter 2 (Apr to June) 2015, published on 30 September 2015. However, rounding can sometimes cause differences between the 3-monthly growth rates presented in this release, compared with the quarterly growth rates presented in the Quarterly National Accounts. Data for the retail industry are broadly comparable with the Retail Sales release, published on 20 August 2015, but as the 2 series operate under different revisions policies, there can be timing differences in the updating of the 2 series. Also, adjustments to the data within the IoS release are sometimes made at the time of the Blue Book to improve the coherence of the 3 approaches to measuring GDP. Therefore, inconsistencies between the 2 series are not unusual but tend to be small. There are also conceptual and coverage differences between retail sales and retail output which can lead to apparent inconsistencies.

  12. Definitions and explanations

    Definitions found within the main statistical bulletin are listed:

    Index number

    An index number is a number which indicates the change in magnitude relative to the magnitude at a specified point, the latter usually taken as 100. For example, the level of services for July 2015 is given in Table 1 as 109.3. This means that services output was 9.3% higher than the average in the reference period, which is currently 2012.

    Seasonal adjustment

    The index numbers in this statistical bulletin are all seasonally adjusted. This aids interpretation by removing annually recurring fluctuations, for example, due to holidays or other regular seasonal patterns. Unadjusted data are also available.

    Seasonal adjustment removes regular variation from a time series. Regular variation includes effects due to month lengths, different activity near particular events such as shopping activity before Christmas, and regular holidays such as the May bank holiday.

    Some features of the calendar are not regular each year, but are predictable if we have enough data, for example, the number of certain days of the week in a month may have an effect, or the impact of the timing of Easter. As Easter changes between March and April, we can estimate its effect on time series and allocate it between March and April depending on where Easter falls. Estimates of the effect of the day of the week and Easter are used respectively to make trading day and Easter adjustments prior to seasonal adjustment.

    X-13-ARIMA-SEATS is the current seasonal adjustment software used for the IoS.

    Value (current price)

    Economic transactions involve the production of goods and the sale of goods and services (commodities). The monetary value (or current price) of these transactions is a product of the quantity produced or sold and the unit price. In a particular period, the total (aggregate) value of all transactions taking place in the economy is simply the sum of the individual transaction values in that period. The current price is sometimes referred to as the “nominal” price.

    Volume (constant price)

    When it comes to comparing the difference in aggregate values between 2 time periods, the observed movement is generally a combination of changes in quantity and changes in price. In a lot of cases, the interest of users of economic data lies in understanding the degree to which economic growth is being driven by changes in quantities (that is, physical volumes of production and consumption). It is standard practice to present many economic statistics as volume series (showing changes in the level of the series that have not been affected by changes in price) and such series are referred to as “at constant prices” or “real” prices.

    Deflation

    The process of removing price changes from a value series and converting to a volume series is known as deflation. All index numbers presented in this bulletin are volume measures and have had the effect of price changes removed.

    Chained volume measures

    The indices in this bulletin are presented as “chained volume” measures, meaning that successive volume estimates have been linked (or chained) together. Annual chain-linking was introduced in 2003 and is considered preferable to producing standard volume series, as chained volume measures more accurately reflect volume changes over time. More information on chain-linking can be found in the Tuke and Reed (2001) (92.8 Kb Pdf) article, and a paper on chain-linking weights in the output approach to measuring GDP can be found on the Methods and Sources page.

    Gross domestic product (GDP)

    The total value of production activity in the economic territory. It is the balancing item on the production account for the whole economy. Domestic product can be measured gross or net of consumption of fixed capital (or depreciation). It is presented in the accounts at market (or purchasers’) prices. A further distinction is that it can be at current prices or chained volume measures.

  13. Methods

    Index of Services methodology can be found on our website.

  14. Composition of the data

    The IoS uses a wide variety of different data, from many sources, which are produced on either an annual, quarterly or monthly basis.

    Some of the indicators are derived using current price turnover deflated by a suitable price index. This includes data from the monthly business survey (MBS): an ONS short-term survey on different parts of the economy. It is one of the main data sources used in the compilation of the IoS.

    More information on monthly business survey data can be found within the Economic and Labour Market Review release (2.65 Mb Pdf).

    Other sources use direct volume measures that don’t need to be deflated, such as Civil Aviation Authority data for air transport. Other proxies, such as employment numbers, are also used. This is the case with Public Sector Employment and Workforce Jobs data.

    Where monthly data are not available (for example, when data are delivered quarterly or annually), monthly estimates are derived by forecasting data. This is done using the X-13-ARIMA-SEATS forecasting method and interpolating a monthly path using a cubic spline.

    An X-13-ARIMA-SEATS forecast is also used where actual data at industry level are not available for the latest period (a lower proportion of actual data are available for the latest month). When the forecast is replaced by actual data, this may lead to revisions to the published data.

    The IoS adheres to the Government Statistical Service Disclosure Control Policy (337 Kb Word document). More information can be found in the Quality and Methodology Information (QMI) (207.3 Kb Pdf) report.

  15. Response rates

    Approximately 42% of the IoS estimates are based on data collected via our monthly business survey (MBS). In addition, approximately 7% of the IoS estimates are collected via our retail sales inquiry (RSI). The remainder is based on data received from other ONS sources and external data sources. The MBS and RSI response rates for data included in this publication are presented for the current months and the 3 months prior in Table 4. The response rates for the previous periods are updated to reflect the current level of response, incorporating data from late returns. There are 2 response rates included; the first is a percentage of the sampled turnover returned and the other is a percentage of the amount of questionnaire forms returned.

    Historical MBS response rates for the services industries as at the time of the relevant publication are also available back to 2010.

  16. Basic quality information

    Some general information on the quality of the Index of Services (IoS) can be found in the “Understanding the Index of Services” section in the main part of this statistical bulletin.

    Additionally, a Quality and Methodology Information (QMI) report for the IoS was published on 11 February 2015. The report pulls together qualitative information on the 5 Eurostat criteria of quality: relevance, accuracy, timeliness and punctuality, accessibility and clarity, and comparability and coherence, and provides a summary of the methods used to compile the IoS output, describing the strengths and limitations of the estimates produced.

    Further quality information, including details of the quality adjustments process for IoS, was published on 31 October 2014 and can be found on the Index of Services methods page on our website.

  17. National accounts revisions policy

    Main documentation explaining the national accounts revisions policy (41.6 Kb Pdf) is available.

  18. Revisions triangles

    SIC 2007 revisions triangles are contained in a zip folder. This folder can be found within the data section of this bulletin.

    Revisions to data provide one indication of the reliability of main indicators. A statistical test has been applied to the average revision to find out if it is statistically significantly different from 0. An average revision close to 0 is desirable as it suggests that revisions are not predictable in any one direction. The result of the test is that the average revision is not statistically significantly different from 0.

    Table 5 presents a summary of the differences published between August 2009 and July 2014 and the estimates published 12 months later.

  19. Publication policy

    Details of the policy governing the release of new data are available from our media relations office. There is also a Pre Release Access List of those given pre-publication access to the contents of this release.

  20. Accessing data

    The data presented in the tables of this statistical bulletin are also available to download from the data section of this publication. A complete run of data is available as a time series dataset on our website.

    We provide an analysis of past revisions in the IoS and other statistical bulletins; more information can be found in Revisions information in ONS First Releases.

  21. Following ONS

    You can follow us on Twitter and Facebook.

  22. Code of Practice for Official Statistics

    National Statistics are produced to high professional standards set out in the Code of Practice for Official Statistics. They undergo regular quality assurance reviews to ensure that they meet customer needs. They are produced free from any political interference.

    The UK Statistics Authority has designated these statistics as National Statistics, in accordance with the Statistics and Registration Service Act 2007 and signifying compliance with the Code of Practice for Official Statistics.

    Designation can be broadly interpreted to mean that the statistics:

    • meet identified user needs
    • are well explained and readily accessible
    • are produced according to sound methods
    • are managed impartially and objectively in the public interest

    Once statistics have been designated as National Statistics it is a statutory requirement that the Code of Practice shall continue to be observed.

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  25. Details of the policy governing the release of new data are available by visiting http://www.statisticsauthority.gov.uk/assessment/code-of-practice/index.html or from the Media Relations Office email: media.relations@ons.gov.uk

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9 . Methodology

Contact details for this Statistical bulletin

Robert Doody
ios.enquiries@ons.gov.uk
Telephone: +44 (0)1633 455803