1. Main points

The Consumer Prices Index (CPI) rose by 0.5% in the year to March 2016, compared with a 0.3% rise in the year to February.

The rate has increased gradually since October 2015 although is still relatively low in the historical context.

Rises in air fares and clothing prices were the main contributors to the increase in the rate between February and March 2016.

These upward pressures were partially offset by a fall in food prices and a smaller rise in petrol prices than a year ago.

CPIH (not a National Statistic) grew by 0.7% in the year to March 2016, up from 0.6% in February.

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2. A brief description of consumer price inflation

Consumer price inflation is the rate at which the prices of goods and services bought by households rise or fall. It is estimated by using price indices. A way to understand this is to think of a very large shopping basket containing all the goods and services bought by households. Movements in price indices represent the changing cost of this basket. An infographic explains how consumer price inflation is calculated. Consumer price indices are published monthly.

A price index can be used to measure inflation in a number of ways. The most common is to look at how the index has changed over a year. This is calculated by comparing the price index for the latest month with the same month a year ago. This is known as the 12-month inflation rate. This bulletin measures inflation to March 2016, so the 12-month rate measures changes in prices between March 2015 and March 2016.

A range of measures of consumer price and other price inflation are published. A tale of many price indices summarises information on the different measures.

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3. Consumer Prices Index (CPI)

What is the CPI?

The CPI is a measure of consumer price inflation produced to international standards and in line with European regulations. First published in 1997 as the Harmonised Index of Consumer Prices (HICP), the CPI is the inflation measure used in the Government’s target for inflation.

The CPI is also used for purposes such as uprating pensions, wages and benefits and can aid in the understanding of inflation on family budgets. For more information see Users and uses of consumer price inflation statistics (2013).

Latest figure and long-term trend

The CPI 12-month rate (the amount prices change over a year) between March 2015 and March 2016 stood at 0.5%. This means that a basket of goods and services that cost £100.00 in March 2015 would have cost £100.50 in March 2016.

The rate has risen gradually since October 2015 although it remains relatively low in the historical context: the CPI 12-month rate had never been below 0.5% from its introduction in 1997 to the end of 2014. Similar to 2015, the downward pull on inflation continues to come from prices for food and non-alcoholic beverages, transport, and recreational and cultural goods and services. The downward pull from transport has reduced this month however. These downward pressures have been counterbalanced by an upward pull from price movements for other goods and services, most notably restaurant and hotel bills, and education costs such as university tuition fees.

Figure A shows the contributions to the CPI 12-month rate in March 2016 compared with the contributions to the 12-month rate a year earlier.

Figure B shows the CPI 12-month rate for the last 10 years. Table A shows the CPI 1-month rate (the amount prices change between 2 consecutive months), 12-month rate and index values for the last year.

Consumer Prices Index (CPI): What are the main movements?

This section explains which goods and services had the biggest impact on the change to the 12-month rate between February and March 2016 and, where relevant, considers the longer-term inflationary trends for these goods and services.

The change in the CPI 12-month rate can be calculated by comparing the 12-month rates for 2 consecutive months. An alternative, and equally valid, approach is to calculate it by comparing the price change between the latest 2 months and the price change between the same 2 months a year ago. Explaining the contribution to change in the 12-month rate (2013) is a diagram explaining the calculation.

The CPI rose by 0.4% between February and March 2016, compared with a rise of 0.2% between the same 2 months a year earlier. The 1-month movement was therefore 0.2 percentage points higher this year compared with a year ago, leading to a rise in the CPI 12-month rate.

Between February and March 2016, the main upward contributions to the change in the CPI 12-month rate came from the following groups.

Transport: prices, overall, rose by 1.7% between February and March this year compared with a rise of 0.7% between the same 2 months a year ago. By far the largest upward effect came from air transport where the timing of Easter contributed to fares rising by 22.9% between February and March 2016. Fares rose by 2.7% between the same 2 months in 2015. There was also a smaller upward effect from rail passenger transport with fares rising this year but falling a year ago. These upward effects were partially offset by a downward contribution from motor fuels with petrol prices rising by 0.9 pence per litre this year compared with a larger rise of 3.8 pence per litre a year ago.

Clothing and footwear: prices, overall, rose by 1.0% between February and March this year compared with a fall of 0.1% between the same 2 months a year ago. Last year was the first time that prices had fallen between February and March since the CPI started in 1996. Normally they rise as they continue to recover following the January sales period. The upward contribution this year came from price movements across a range of women’s outerwear.

Restaurants and hotels: prices, overall, rose by 0.5% between February and March 2016 compared with a rise of 0.2% between the same 2 months a year ago. The upward effect came principally from restaurant and café prices rising by more than a year ago.

The main downward contribution to the change in the CPI 12-month rate between February and March 2016 came from food and non-alcoholic beverages where prices, overall, fell by 0.6% between February and March this year compared with a fall of 0.2% between the same 2 months a year ago. The overall downward contribution came from a variety of product groups, most notably vegetables.

Figure C shows the contributions to change from each part of the CPI basket of goods and services.

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4. CPIH

CPIH has been re-assessed to evaluate the extent to which it meets the professional standards set out in the Code of Practice for Official Statistics and the assessment report published on 3 March 2016. The report includes a number of requirements that need to be implemented for CPIH to regain its status as a National Statistic. The actions taken to address these requirements will be reported to the UK Statistics Authority by September 2016.

CPIH is a measure of UK consumer price inflation that includes owner occupiers’ housing costs (OOH). These are the costs of housing services associated with owning, maintaining and living in one’s own home. OOH does not include costs such as utility bills, minor repairs and maintenance, which are already included in the index.

CPIH uses an approach called rental equivalence to measure OOH. Rental equivalence uses the rent paid for an equivalent house as a proxy for the costs faced by an owner occupier. In other words this answers the question “how much would I have to pay in rent to live in a home like mine?” for an owner occupier. OOH does not seek to capture increases in house prices. Although this may be inconsistent with some users’ expectations of measures of OOH, the inclusion of an asset price and therefore capital gains would make the index less suitable for a measure of consumption. OOH currently accounts for 16.5% of the expenditure weight of CPIH. This compares with a weight of 19.5% in 2005.

Currently, the method of calculation, the population coverage and the basket of goods and services are the same as the Consumer Prices Index (CPI), with the exception of OOH. The method of deriving the weights for CPIH and the data used for these are also the same as for CPI, with the exception of OOH. This can result in some differences from the CPI.

In March 2016, the 12-month rate (the rate at which prices increased between March 2015 and March 2016) for CPIH stood at 0.7%, up from 0.6% in February 2016. The difference between the CPI and CPIH annual rates in March 2016 was 0.2 percentage points, down from 0.3 percentage points in February. The smaller rise in the CPIH 12-month rate compared with the CPI 12-month rate was principally due to rounding plus a smaller upward contribution from air fares, resulting from the lower weight of this group in CPIH.

Owner occupiers’ housing costs increased by 0.2% between February and March 2016, compared with 0.1% between these months a year earlier. This meant they had a small upward impact on the change in the CPIH 12-month rate between the 2 months.

Figure D shows the CPIH and OOH component 12-month rates for the last 10 years. The CPI 12-month rate has been included for comparative purposes. Table B shows the CPIH and OOH component 1-month and 12-month rates and index values for the last year.

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5. Retail Prices Index (RPI) and RPIJ

In accordance with the Statistics and Registration Service Act 2007, the Retail Prices Index and its derivatives have been assessed against the Code of Practice for Official Statistics and found not to meet the required standard for designation as National Statistics. The full assessment report can be found on the UK Statistics Authority website.

The RPI is a long-standing measure of UK inflation that has historically been used for a wide range of purposes such as the indexation of pensions, rents and index-linked gilts. For further information see Users and uses of consumer price inflation statistics (2013).

RPIJ is an improved variant of the Retail Prices Index, which is calculated using formulae that meet international standards. The rationale for creating RPIJ was to give users a better alternative to the RPI if their needs were for a measure of inflation based on the same population, classifications, weights, etc as the RPI. Currently, RPIJ also acts as an analytical series in that it allows users to see the impact of using the Jevons (which meets international standards) in place of the Carli formula (which does not meet international standards) in the RPI. The use of the different formulae at the elementary aggregate level is currently the only difference between the 2 indices. Detailed goods and services indices are not produced for RPIJ.

In March 2016, the 12-month rate for RPIJ stood at 0.8%, up from 0.6% in the year to February.

The RPI 12-month rate for March 2016 stood at 1.6%, meaning that it was 0.8 percentage points higher than it would have been had it used formulae that meet international standards.

Figure E shows the RPI and RPIJ 12-month rates for the last 10 years. Over this period the RPIJ 12-month rate has been, on average, 0.5 percentage points lower than the RPI but the difference has increased to an average of 0.6 percentage points over the last 3 years.

Table C shows the RPI and RPIJ 1-month and 12-month rates and index values for the last year.

For users who want to understand the causes of the difference between the CPI and RPI, please see Table 5 in the Consumer Price Inflation dataset.

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6. Guide to data

Table D outlines where data for all consumer price inflation statistics can be found.

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7.Background notes

  1. News

    Future of Consumer Inflation Statistics

    On 9 March 2016 the UK Statistics Authority published a letter from the National Statistician to the Chair of the Authority about the future of consumer inflation statistics. This gave an update on his current thinking of this future. Also published was the advice from the new consumer price panels which helped to shape his view.

    Re-assessment of CPIH

    CPIH has been re-assessed to evaluate the extent to which it meets the professional standards set out in the Code of Practice for Official Statistics and the assessment report published on 3 March 2016. The report includes a number of requirements that need to be implemented for CPIH to regain its status as a National Statistic. The actions taken to address these requirements will be reported to the UK Statistics Authority by September 2016.

    Estimated Effect of the Budget on Consumer Price Inflation

    Budgetary measures that come into force in 2016 to 2017 will add an estimated 0.05 percentage points to the CPI 1-month rate. Further details are available in Estimated Effect of the Budget on CPI and RPI: Spring 2016 which was published on 24 March 2016.

  2. Understanding and accessing the data

    A full description of how consumer price indices are compiled is given in the Consumer Price Indices Technical Manual. This is supplemented by infographics and further information available from the guidance and methodology section of our archived website.

    A more detailed quality report for this statistical bulletin is available. The report assesses consumer price inflation statistics against standard dimensions of quality such as relevance, accuracy and accessibility. The report was last updated in October 2013.

    The mini Triennial Review of the CPI and RPI Central Collection of Prices is available.

    All consumer price inflation data including Excel dataset, time series data and explorable datasets can be found on the dataset page.

    To help users further, very detailed data are available including the individual price quotes (for locally collected items only) and item indices that underpin the CPI. Please note, the data that are published are at a level which means that no individual retailer or service provider will be able to be identified. The data published cover January 1996 to December 2015. These data are updated once a quarter with around a 2-month lag with the latest CPI publication. For example, the data will next be updated when the May CPI is published on 14 June 2016, at which point the detailed data published will be extended to March 2016.

    Internationally, the CPI is known as the Harmonised Index of Consumer Prices (HICP). HICPs are calculated in each member state of the European Union according to rules specified in a series of European regulations developed by the European Commission (Eurostat) in conjunction with the EU member states. Eurostat releases figures for the Harmonised Index of Consumer Prices (HICP) for the month of March 2016 for EU member states, together with an EU average, on 14 April 2016. A summary of the latest European data is available from Eurostat’s database tables. Further information on HICP for the European Union, Euro area and other EU member states is available from Eurostat's HICP web page.

  3. Methods - CPI and other measures of inflation

    The CPI, CPIH, RPIJ and RPI are compiled using the same underlying price data, based on a large and representative selection of around 700 individual goods and services for which price movements are measured in around 140 randomly selected areas throughout the UK. Around 180,000 separate price quotations are used every month to compile the indices. The outlets in which the prices are collected are selected randomly. Expenditure weights are held constant for 1 year at a time.

    The selection of goods and services that are priced to compile these indices is reviewed annually. The contents of the 2016 basket are described in an article Consumer Price Inflation: The 2016 Basket of Goods and Services. The expenditure weights used to compile the indices are also updated each year. Additional details of the updated weights for 2016 are available in an article published on 22 March 2016 entitled Consumer Price Inflation: 2016 Weights.

    Rates of change for the CPI and CPIH are calculated from unrounded index levels, rather than from the published indices which are rounded to 1 decimal place. The use of unrounded indices increases the accuracy of the calculation. The unrounded index levels for the CPI and CPIH are available from Tables 63 and 64 of the Consumer Price Inflation dataset. By contrast, rates of change for the RPI and RPIJ are calculated from the published rounded indices.

    Further information on the methods used to construct the CPI, CPIH, RPI and RPIJ, including differences in the methods used for each index can be found in the Consumer Price Indices Technical Manual. Users and uses of consumer price inflation statistics (2013) provides further details of how consumer price statistics are used more generally.

  4. Revisions policy

    On 15 October 2013, a revisions policy was published for the suite of consumer price inflation statistics. The policy reaffirms the existing practices for CPI and RPI and sets out the policies for the new CPIH and RPIJ measures.

    In summary, CPI, CPIH and RPIJ are revisable in theory though revisions only occur under exceptional circumstances. The RPI is never revised once published.

  5. Publication policy

    This bulletin includes the March 2016 data, collected on and around 15 March 2016. Future publication dates for this statistical bulletin are available to January 2018 (the publication of the December 2017 inflation figures). Publication dates from February 2017 onwards are provisional.

    Consumer price inflation for April 2015 to April 2016 will be published on 17 May 2016.

  6. Other contact details

    Consumer Price Inflation recorded message (available after 9.45am on release day):
    Tel: + 44 (0) 800 0113703

    Consumer Price Inflation Enquiries:
    Tel: + 44 (0) 1633 456900

  7. Code of Practice

    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 and released according to the arrangements approved by the UK Statistics Authority.

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