A series for the GDP deflator in index form is produced by the Treasury from data provided by the Office for National Statistics (ONS) and the Office for Budget Responsibility (OBR). The GDP deflator set is updated after every ONS Quarterly National Accounts release (at the end of each quarter) and whenever the OBR updates its GDP deflator forecasts (usually twice a year).

Outturn data are the latest Quarterly National Accounts figures from the ONS, 20 December 2013. GDP deflators from 1955-56 to 2012-13 (1955 to 2012) have been taken directly from ONS Quarterly National Accounts implied deflator at market prices series http://www.ons.gov.uk/ons/datasets-and-tables/data-selector.html?cdid=L8GG&dataset=qna&table-id=N" class="govuk-link">L8GG.

Forecast data are consistent with the Autumn Statement, 05 December 2013.

Gross Domestic Product (GDP) deflators: a user’s guide

The detail below aims to provide background information on the GDP deflator series and the concepts and methods underlying it.

GDP deflators can be used by anyone who has an interest in deflating current price nominal data into a “real terms” prices basis. This guide has been written with casual as well as professional users of the data in mind, using language and concepts aimed at as wide an audience as possible.

Overview of GDP deflator series

What is the GDP deflator?

The GDP deflator can be viewed as a measure of general inflation in the domestic economy. Inflation can be described as a measure of price changes over time. The deflator is usually expressed in terms of an index, i.e. a time series of index numbers. Percentage changes on the previous year are also shown. The GDP deflator reflects movements of hundreds of separate deflators for the individual expenditure components of GDP. These components include expenditure on such items as bread, investment in computers, imports of aircraft, and exports of consultancy services.

Uses of the GDP deflator series

The series allows for the effects of changes in price (inflation) to be removed from a time series, i.e. it allows the change in the volume of goods and services to be measured. The resultant series can be used to express a given time series or data set in real terms, i.e. by removing price changes.

Where do the figures come from?

A series for the GDP deflator in index form is produced by the Treasury from data provided by the Office for National Statistics (ONS). Forecasts are produced by the Office for Budgetary Responsibility (OBR) and are usually updated around the time of major policy announcements, namely; the Chancellor’s Autumn Statement, and the Budget.

Rounding Convention

GDP deflators for earlier years (up to and including the most recent year for which full quarterly data have been published) are presented to 3 decimal places. The index for future years has been removed as the forecasts were not as accurate as this detail would suggest. Percentage year-on-year changes are given to two decimal places for earlier years, forecast years are presented to 1 decimal place as published in the Autumn Statement and the Budget.

Updates

• updates to earlier years (up to and including the most recent year for which full quarterly data have been published) shortly after the ONS Quarterly National Accounts release
• when the OBR updates its forecasts, shortly after the Budget and again after the Chancellor’s Autumn statement

Background information on GDP and GDP deflator

What is GDP?

Gross Domestic Product (GDP) is a measure of the total domestic economic activity. It is the sum of all incomes earned by the production of goods and services within the UK economic territory. It is worth noting that where the earner of the income resides is irrelevant, so long as the goods or services themselves are produced within the UK. GDP is equivalent to the value added to the economy by this activity. Value added can be defined as income