Introduction
The Office for National Statistics (ONS) publishes annual estimates of Gross Domestic Product (GDP) for local and regional geographies. These are usually available about 16 months after the end of the calendar year that they cover.
GDP is allocated to the area in which the related economic activity takes place. Because areas vary in the size of their population, a rate based on the number of residents is used to compare their GDPs. This rate should not be used as a proxy for productivity, which uses a denominator based on the workplace population such as the number of workers or hours worked. Variances in employment rates and in hours worked also make GDP per head inappropriate as a productivity measure.
Headline GDP totals and rates in the ONS release are current price measures. However, for rates of change, ONS produce a time series of chained volume measures that removes the effects of inflation. This is described in the release as a time series of real GDP. This is especially useful to reveal patterns of GDP change in periods where inflation has been high or volatile, including recent years.
In some releases, Gross Value Added (GVA) is used instead of GDP. This is true for the annual breakdown by industry and for earlier releases of the sub-national data charted in this report. The relationship between GDP and GVA is:
GDP = GVA + VAT + other taxes on products - subsidies on products