Export Statistics Scotland: methodology

Due to evidence that inflation was exerting an especially strong influence in the economy over recent years, it was decided to reimplement methodology to deflate the current price series. This analysis produces the real terms figures.

The purpose of this analysis is to improve the accuracy of Scotland’s export statistics by attempting to capture inflation effects in the data. This approach is consistent with that used in Scotland’s Quarterly National Accounts. Please note that this methodology is in development and will continue to improve in future years.

The methodology involves matching deflators for the appropriate year, industry and export type to the data. For manufactured goods there are domestic producer price indices for exports to the rest of the UK, and export producer price indices for international exports. For the output of other industries the same price indices are used for both exports to the rest of the UK and exports to the rest of the world.

The detailed volume series are weighted together to produce aggregate volume indices for broad industries and total exports. Growth from one year to the next is estimated by weighting the individual series together using their contribution to the value of trade in the immediately preceding year. For example, growth between 2015-2016 uses weights from 2015; growth between 2014-2015 uses weighs from 2014, etc.. This series of annually re-weighted annual growths is then “chain-linked” to produce a continuous series, or chainlinked volume measure (CVM).

Finally, the series are indexed to the year 2008. This means that changes in real terms are shown relative to the current price value in 2008. The choice of reference year is presentational only, and does not have any effect on growth rates in the results.