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Statistical bulletin: Index of Services, October 2015 This product is designated as National Statistics

Released: 23 December 2015 Download PDF

Main points

  • The Index of Services is estimated to have increased by 2.1% in October 2015 compared with October 2014. Three of the 4 main components of the services industries increased in the most recent month compared with the same month a year ago, while 1 decreased.
  • The largest contribution to total growth came from: distribution, hotels and restaurants, which contributed 0.9 percentage points; in contrast, government and other services had a slight negative contribution.
  • The latest Index of Services estimates show that output increased by 0.1% between September 2015 and October 2015, following growth of 0.5% between August 2015 and September 2015.
  • The Index of Services increased by 0.6% in Quarter 3 (July to Sept) 2015 compared with Quarter 2 (Apr to June) 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 27 November 2015 and is consistent with the Quarterly National Accounts, published on 23 December 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 2014.

Understanding the Index of Services (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 services 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 communications

  • 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 11.

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 17.

It should be noted that care should be taken when using the month-on-month growth rates, due to their volatility (background note 10).

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.

Main information

Table 1: Index of Services main information, October 2015

UK

Percentage change
  Index number (2012=100) Most recent month on a year earlier Most recent 3 months on a year earlier Most recent month on previous month Most recent 3 months on previous 3 months
Index of services 109.6 2.1 2.3 0.1 0.5

Table source: Office for National Statistics

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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 GDP. Index values are currently 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 2.1% in October 2015 compared with October 2014. In order of their contribution to growth (listed in reference table IOS1):

  1. distribution, hotels and restaurants increased by 5.1%

  2. business services and finance increased by 2.0%

  3. transport, storage and communications increased by 3.4%

In contrast government and other services decreased by 0.1%

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

Figure 1: IoS contributions (1) to the month-on-month a year ago percentage change, October 2015

UK

Figure 1: IoS contributions (1) to the month-on-month a year ago percentage change, October 2015
Source: Office for National Statistics

Notes:

  1. Individual contributions may not sum to the total due to rounding.
  2. Percentage change.
  3. Please click on image to view larger version.

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Between September 2015 and October 2015, as seen in Figure 2, IoS output increased by 0.1%.

Out of the 4 main components of the services industries, 3 increased in the most recent month compared with the previous month. In order of their contribution to growth (listed in reference table IOS1):

  1. distribution, hotels and restaurants increased by 0.5%

  2. business services and finance increased by 0.1%

  3. transport, storage and communications increased by 0.2%

In contrast, government and other services decreased by 0.1%.

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 October 2015 compared with the previous 3 months and compared with the 3 months ending October 2014.

Figure 2: IoS contributions (1) to the month-on-month percentage change, October 2015

UK

Figure 2: IoS contributions (1) to the month-on-month percentage change, October 2015
Source: Office for National Statistics

Notes:

  1. Individual contributions may not sum to the total due to rounding.
  2. Percentage change.
  3. Please click on image to view larger version.

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Economic background

Total services grew by 2.4% between Quarter 3 (July to Sept) 2014 and Quarter 3 (July to Sept) 2015 and by 0.6% between Quarter 2 (Apr to June) 2015 and Quarter 3 (July to Sept) 2015. This was slightly faster than the growth rates of 2.1% and 0.4% respectively for the economy as a whole.

Since 1997, the services industries as a whole have grown at a faster rate than all other headline industries. While GDP has grown at a compound average (further information on compound average growth can be found in background note 11) annual growth rate of 2.0% since 1997, services have grown at a compound average growth rate of 2.8% per year (more information can be found in Quarterly National Accounts – Quarter 3 (July to Sept) 2015). This has led to a continuing re-orientation of the economy towards services, despite productivity in the services industries as a whole rising more slowly than in the production industries (and manufacturing in particular) since 1997 (more information can be found in Labour Productivity, Quarter 3 (July to Sept) 2015). The higher output growth, therefore, reflects the increasing share of the labour force employed in services, which grew from 73% to 79% between 1997 and 2014 (Labour Market Statistics, December 2015, reference table EMP13).

In addition to strong long-run growth, the services industries as a whole were also less affected by the downturn in 2008 than other headline 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 headline industry grouping to have surpassed its pre-downturn peak levels (more information can be found in Quarterly National Accounts – Quarter 3 (July to Sept) 2015).

Even though the services industries as a whole 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 services industries as a whole, both at compound average growth rates of 3.7% per year, while services 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 services industries as a whole (at compound average growth rates of 1.7% and 1.8% per year respectively) between 1997 and 2014.

The economy’s downturn, Quarter 1 (Jan to Mar) 2008 to Quarter 2 (Apr to June) 2009, impacted the 4 sub-components of the 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 services industries as a whole 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 economy’s downturn and in Quarter 3 (July to Sept) 2015, they were 14.2% and 11.0% 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 3 (July to Sept) 2015, output was 9.8% above pre-downturn levels. However, the recovery of the government and other services industries was more modest, and in Quarter 3 (July to Sept) 2015, output was 6.9% above its Quarter 1 (Jan to Mar) 2008 value.

Figure 3: Index of Services and sub-components, Quarter 1 (Jan to Mar) 1997 to Quarter 3 (July to Sept) 2015

UK

Figure 3: Index of Services and sub-components, Quarter 1 (Jan to Mar) 1997 to Quarter 3 (July to Sept) 2015
Source: Office for National Statistics

Notes:

  1. Q1 is Quarter 1 (Jan to Mar); Q2 is Quarter 2 (Apr to June); Q3 is Quarter 3 (July to Sept); and Q4 is Quarter 4 (Oct to Dec).
  2. Please click on image to view larger version.

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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 78% of nominal GVA.

Figure 4: Services as a percentage of nominal GVA in comparable economies (1) to the UK

1997 to 2013

Figure 4: Services as a percentage of nominal GVA in comparable economies (1) to the UK
Source: Office for National Statistics, Organisation for Economic Co-operation and Development

Notes:

  1. OECD data correct at 16 December 2015.
  2. Please click on image to view larger version.

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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 3 (July to Sept) 2015, GDP was estimated to have increased by 0.4% 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.

Figure 5: GDP contribution (1) to the quarter-on-quarter percentage change, Quarter 3 (July to Sept) 2015

UK

Figure 5: GDP contribution (1) to the quarter-on-quarter percentage change, Quarter 3 (July to Sept) 2015
Source: Office for National Statistics

Notes:

  1. Contributions are to output gross value added and therefore may not sum to the percentage change in GDP. More information on the difference between the 2 measures can be found in the Short Guide to National Accounts.
  2. Percentage change to 1 decimal place.
  3. Please click on image to view larger version.

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Monthly estimates are produced for each industrial grouping except agriculture. The October 2015 estimates for production and construction were published on 8 December 2015 and 11 December 2015 respectively. Quarterly National Accounts for Quarter 3 (July to Sept) 2015 was published on 23 December 2015 alongside this bulletin.

Table 2: GDP output component tables, Quarter 3 (July to Sept) 2015, chained volume measure, seasonally adjusted

UK

Percentage change
Publication % of GDP Release date Period of GDP Most recent quarter on a year earlier Most recent quarter on a quarter earlier Most recent month on the same month a year ago Most recent month on the previous month
               
Index of Production 14.9 08 Dec Oct 2015 .. .. 1.7 0.1
      Q3 20151 1.4 0.2 .. ..
      Q2 20152 1.4 0.7 .. ..
 
Construction output 5.9 11 Dec Oct 2015 .. .. 1.0 0.2
      Q3 2015 1.0 -1.9 .. ..
      Q2 2015 5.4 0.3 .. ..
               
Index of Services 78.6 23 Dec Oct 2015 .. .. 2.1 0.1
      Q3 2015 2.4 0.6 .. ..
      Q2 2015 2.5 0.5 .. ..
               
Retail Sales3   19 Nov Oct 2015 .. .. 3.8 -0.6
      Q3 2015 4.9 0.9 .. ..
      Q2 2015 4.3 0.7 .. ..
               
Agriculture 0.7   Q3 2015 -0.1 0.2 .. ..
      Q2 2015 1.7 0.4 .. ..

Table source: Office for National Statistics

Table notes:

  1. Q3 refers to Quarter 3 (July to Sept).
  2. Q2 refers to Quarter 2 (Apr to June).
  3. Data are presented as at 19 November 2015 due to timing of the availability of the data.
  4. Individual weights may not sum to total due to rounding.
  5. No data represented by ..

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Component analysis

Table 3: Growth rates and contributions (1) to the Index of Services, October 2015

UK

Percentage change
Description % of Services Month on a year earlier Volume (SA2) (%) Contribution to services (% points) Month on month growth Volume (SA) (%) Contribution to services (% points)
Total services industries 100 2.1 2.1 0.1 0.1
           
Distribution, hotels and restaurants 17 5.1 0.9 0.5 0.1
           
Transport, storage and communication 13 3.4 0.5 0.2 0.0
           
Business services and finance 40 2.0 0.8 0.1 0.0
           
Government and other services 30 -0.1 0.0 -0.1 0.0
 

Table source: Office for National Statistics

Table notes:

  1. Individual contributions may not sum to the total due to rounding.
  2. SA = seasonally adjusted.

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Distribution, hotels and restaurants

The index of distribution, hotels and restaurants increased by 5.1% in October 2015 compared with October 2014, this follows an increase of 4.7% in September 2015 compared with the same month a year earlier. The largest contribution to the increase was retail trade, except of motor vehicles and motorcycles, which increased by 3.8% and wholesale and repair of motor vehicles and motorcycles, which increased by 10.2%.

Transport, storage and communications

The index of transport, storage and communications increased by 3.4% in October 2015 compared with October 2014; this follows an increase of 4.1% in September 2015 compared with the same month a year earlier. The main contributors to the increase were: publishing, audiovisual and broadcasting activities, which increased by 11.6% and computer programming, consultancy and related activities, which increased by 4.5%.

Business services and finance

The index of business services and finance increased by 2.0% in October 2015 compared with October 2014; this follows an increase of 2.6% in September 2015 compared with the same month a year earlier. The main contributors to the increase were: administrative and support services activities, which increased by 5.0% and real estate activities, which increased by 2.2%.

Government and other services

The index of government and other services decreased by 0.1% in October 2015 compared with October 2014; this follows an increase of 0.1% in September 2015 compared with the same month a year earlier. The main contributors to the decrease were: public administration and defence; compulsory social security, which decreased by 2.8% and other service activities, which decreased by 2.4%.

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 17.

In this release of data, the earliest period open to revision is January 2014. Across the open period there are small revisions to the month-on-month growth rates, the maximum absolute change is 0.1 percentage points. The cumulative effect of these revisions has led to some slightly larger increases to the month-on-year-ago revisions which can be found in the full revisions analysis.

In the most recent months, the month-on-month growth rate revisions are:

  • August 2015 compared with July 2015 has been revised down 0.1 percentage points from the previously published estimate (0.0%)

  • September 2015 compared with August 2015 has been revised up 0.1 percentage points from the previously published estimate (0.4%)

In addition to usual factors, revisions reflect the availability of a number of 2014 annual benchmark series in the current production round.

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

Industry spotlight: Information service activities

According to the UK Standard Industrial Classification 2007 (SIC2007), information service activities (industry 63) includes the activities of web search portals, data processing and hosting activities, as well as other activities that primarily supply information. This industry has 2 divisions: data processing, hosting and related activities; web portals (division 63.1) and other information service activities (division 63.9).

In 2014, information service activities generated £5.1 billion of output gross value added (GVA) in current prices, which represented 5.1% of the GVA in the information and communication section (section J). The share of total output attributed to this industry increased between 1997 and 2014 from 0.2% to 0.3%, suggesting that the industry grew faster than the rest of the economy (Quarterly National Accounts – Quarter 3 (July to Sept) 2015).

Figure 6 shows that in the period from 1997 to 2015, information service activities performed better than the services industries as a whole. Between Quarter 1 (Jan to Mar) 1997 and Quarter 1 (Jan to Mar) 2008 this industry followed a broadly upward but volatile trend growing at a compound average growth rate of 2.4% per quarter. The industry’s (pre-downturn) upward trend consisted of 2 distinct periods, high and steady growth between Quarter 1 (Jan to Mar) 1997 and Quarter 4 (Oct to Dec) 2000, followed by slower and more volatile growth between Quarter 4 (Oct to Dec) 2000 and Quarter 1 (Jan to Mar) 2008. Services experienced slower growth (a compound average growth rate of 0.9% per quarter) over the pre-downturn period (further information on compound average growth can be found in background note 11).

During the economy’s downturn, Quarter 1 (Jan to Mar) 2008 and Quarter 2 (Apr to June) 2009, the output of the services industries as a whole and information service activities contracted at different times and to different extents. Services started to contract in Quarter 2 (Apr to June) 2008, and its output fell by 4.1% between the industries’ peak in Quarter 1 (Jan to Mar) 2008 and its trough in Quarter 2 (Apr to June) 2009. However, the information service activities industry did not begin its decline until Quarter 3 (July to Sept) 2008, and its output decreased by 17.9% between Quarter 2 (Apr to June) 2008 and the industry’s trough in Quarter 3 (July to Sept) 2009.

Information service activities and the services industries as a whole recovered strongly following their respective periods of contraction. Services grew steadily at a compound average growth rate of 0.6% per quarter (between Quarter 2 (Apr to June) 2009 and Quarter 3 (July to Sept) 2015), surpassing its pre-downturn peak in Quarter 1 (Jan to Mar) 2012. Information service activities grew relatively faster despite some volatility, at a compound average growth rate of 1.7% per quarter (between Quarter 3 (July to Sept) 2009 and Quarter 3 (July to Sept) 2015), surpassing its Quarter 2 (Apr to June) 2008 level by Quarter 4 (Oct to Dec) 2012. By Quarter 3 (July to Sept) 2015, the services industries as a whole was 10.8% above its value in Quarter 1 (Jan to Mar) 2008, while information service activities was 22.2% above its value in Quarter 2 (Apr to June) 2008.

Figure 6: Index of Services and information service activities

UK, 1997 to 2015

Figure 6: Index of Services and information service activities
Source: Office for National Statistics

Notes:

  1. Q1 is Quarter 1 (Jan to Mar); Q2 is Quarter 2 (Apr to June); Q3 is Quarter 3 (July to Sept); and Q4 is Quarter 4 (Oct to Dec).
  2. Please click on image to view larger version.

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Information service activity products are used in the production processes (as intermediate consumption) of a range of industries, totalling £7.6 billion in 2013 and representing 0.5% of total intermediate consumption in this year. In 2013, around 14.5% of the intermediate consumption of this industry’s products can be attributed to 5 industries (creative, art and entertainment activities, information service activities, security and investigation activities, advertising and market research, and repair of computers and personal and household goods). Between 1997 and 2013, creative, arts and entertainment activities consistently used the highest amount of information service activities as a share of its total intermediate consumption, even though this share decreased by 6.1 percentage points between 1997 and 2013 (from 21.9% in 1997 to 15.8% in 2013) (Input-Output Supply and Use tables, 2015 edition).

Background notes

  1. Continuous improvement of GDP

    The GDP Output Improvement Report, published on 30 September 2015, provided 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.

    To reflect these improvements along with updated weights the GDP(O) source catalogue, was updated alongside the Blue Book publication on 30 October 2015.

  2. Experimental statistics

    The Index of Services (IoS) achieved National Statistic status in 2007; this was 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 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.

  3. VAT project update

    An article entitled "HMRC VAT project update" was published on 21 December 2015, the third in a series of articles. It outlined plans to use HMRC VAT turnover data as a pilot to replace MBS in summer 2016 for parts of the Index of Services and the Output approach to measuring GDP. 

    The first article titled “Feasibility study into the use of HMRC turnover data within Short-term Output Indicators and National Accounts” was published on 14 August 2015. It explored ways in which HM Revenue & Customs (HMRC) administrative data could be used to quality assure, supplement or replace the current turnover-based ONS surveys.

    A second article, "Exploitation of HMRC VAT data", was published on 7 October 2015. This article explored the international context of the work, described previous attempts to use these data in short-term economic output indicators and National Accounts, and gave a high level overview of the process undertaken to arrive at micro-level data each month.

  4. 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.gsi.gov.uk.

  5. 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.

  6. Understanding the data

    Short guide to the Index of Services

    The Index of Services (IoS) 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 communications (sections H and J), business services and finance (sections K to N), and government and other services (sections O to T).

  7. 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.

  8. 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) .

  9. 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.

  10. 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 Quarterly National Accounts for Quarter 3 (July to Sept) 2015, published on 23 December 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 19 November 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.

  11. 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 October 2015 is given in Table 1 as 109.6. This means that services output was 9.6% 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. Where information on prices is not available, but value and volume data are, an implied deflator (or price) can be derived by dividing the first by the latter. All index numbers presented in this bulletin are volume measures and have had the effect of price changes removed unless otherwise stated.

    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 effects of annual chain-linking on the output measure of GDP (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.

    Compound average growth

    Compound average growth is the rate at which a series would have increased or decreased if it had grown or fallen at a steady rate over a number of periods. This allows the composition of growth in the recent economic recovery to be compared to the long run average.

    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.

  12. Methods

    Index of Services methodology can be found on our website.

  13. 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.

  14. 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.

    Table 4: Survey response rates, October 2015

    UK

    Response rates (%)
    Period July 2015 Aug 2015 Sept 2015 Oct 2015
             
    Monthly Business Survey (Services)        
             
    Turnover 95.9 96.1 95.3 89.3
    Questionnaire 84.7 84.1 82.0 75.3
             
    Retail Sales Inquiry        
             
    Turnover 98.8 98.3 94.3 90.1
    Questionnaire 77.2 77.1 75.6 64.7

    Table source: Office for National Statistics

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

  15. 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.

  16. National accounts revisions policy

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

  17. 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 November 2009 and October 2014 and the estimates published 12 months later.

    Table 5: Revisions between first publication and estimates 12 months later

    UK

    Percentage change
      Value in latest period Average over the last 60 months Average over the last 60 months without regard to sign (average absolute revision)
    Index of Services 3 month on 3 month growth rate 0.5 -0.06 0.17
    Index of Services 1 month on 1 month growth rate 0.1 -0.02 0.17

    Table source: Office for National Statistics

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  18. 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.

  19. 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.

  20. Following ONS

    You can follow us on Twitter and Facebook.

  21. 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.

  22. Next publication: Thursday 28 January 2016

    Issued by: Office for National Statistics, Government Buildings, Cardiff Road, Newport NP10 8XG

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

Statistical contacts

Name Phone Department Email
Robert Smith +44 (0)1633 651618 Office for National Statistics ios.enquiries@ons.gsi.gov.uk
Get all the tables for this publication in the data section of this publication .
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