Export Statistics Scotland: methodology

Export Statistics Scotland 2021: time series and new data source

Export Statistics Scotland links the data on businesses in one year with previous years. Business level identifiers are present in the microdata, making this possible. Some businesses may have moved industry sector between years, which can impact how changes over time for industry sectors are interpreted. The methodology aims to minimise the impact of this and where possible, takes measures to allocate businesses to SIC codes consistently across years.

When considering exports by business size over time, it should be noted that some businesses will change size, and therefore change size category, between years.

Up until and including ESS 2019, data was available from 2002 to 2019, however the ESS 2021 only provides data from 2019 to 2021 and this data is not comparable to estimates for previous years. This is due to a new data source being included in ESS 2021. 

Several different data sources are used to obtain business turnovers, which are used to estimate the value of exports. Prior to ESS 2021, one of the main sources of turnover was the ONS Inter-Departmental Business Register (IDBR).  

The Office for National Statistics (ONS) maintains the IDBR. This is a database of all registered businesses operating in the UK, i.e. businesses registered for VAT and/or PAYE. It covers 99% of economic activity in the UK. It excludes small sole traders. It also excludes partnerships with no employees and an annual turnover of less than the VAT threshold. On the IDBR, the basis for turnover is VAT returns for a 12 month period. This is the case for the majority of registered businesses. However, for some records, turnover may relate to an earlier period or survey data.  

The COVID-19 pandemic made the impact of any time lags in turnover data in the IDBR more evident, so turnover in ESS was instead sourced from the Scottish Annual Business Statistics (SABS). This was possible since the timetable for ESS 2021 publication had been delayed. The sampling frame used for the SABS is the IDBR but turnover is collected for the survey year in question (meaning data is not from a range of sources or time periods, as it is in the IDBR). Please note the SABS covers about two thirds of the whole economy, it excludes the financial sector and parts of the agriculture and public sector.  

However, changing the primary turnover data source means that the new estimates in ESS 2021 are not comparable with previously published estimates for earlier years, as they do not include the SABS data source.  

Since ESS estimates export value as a proportion of a business’ turnover, using a different turnover value will change the resulting export value. This means that the estimated values for 2019 in the ESS 2021 publication are different from those published in ESS 2019. The direction and size of the differences vary depending on the destination and industry, but overall, the revised estimates for Scotland’s total exports (international and rest of the UK) for the year 2019 were approximately £5 billion lower in the ESS 2021 publication than in ESS 2019. 

The difference in the estimated value for Scotland’s international exports for the year 2019 was similar in the two publications, however, there has been a bigger impact on exports to the rest of the UK.  Including the new data source has resulted in a decrease of 10.3% in the estimate for the year 2019 for Scotland’s exports to the rest of the UK, as the estimate dropped from £52.0 billion to £46.7 billion.  

Table 2. Estimated value of Scotland’s exports for 2019, in £ billion, as shown in ESS 2019 and ESS 2021, because the latter publication includes a different data source for business turnovers 

The drop in the estimated export value to the rest of the UK for the year 2019 between the two publications is driven by the estimate for exports of utilities dropping by half (down £3.7 billion), from £7.3 billion in ESS 2019 to £3.7 billion in ESS 2021. 

Figure 1. The biggest difference in the estimated export values for the year 2019 was for exports to the rest of the UK 

Estimated value of Scotland’s exports for the year 2019, in £ billion, as shown in ESS 2019 and ESS 2021 publications, because the latter publication includes a different data source for business turnovers. 

Figure 2. The biggest percentage difference in estimated value of exports to the rest of the UK for 2019 was for exports of utilities 

Percentage change in the estimated value of Scotland’s exports to the rest of the UK for the ten industry sectors with the largest percentage differences for 2019, between ESS 2019 and ESS 2021, because the latter publication includes a different data source for business turnovers.

Table 3. Estimated value of Scotland’s exports to the rest of the UK for the year 2019 for the industries with the largest percentage change between ESS 2019 and ESS 2021 publications. Values are in £ million and rounded to the nearest £5 million. 

Figure 3. The biggest percentage difference in estimated value of international exports for the year 2019 was for exports of transportation and storage 

Percentage change in the estimated value of Scotland’s international exports for the ten industry sectors with the largest percentage differences for the year 2019, between ESS 2019 and ESS 2021, because the latter publication includes a different data source for business turnovers.   

Table 4. Estimated value of Scotland’s international exports for the year 2019 for the industries with the largest percentage change between ESS 2019 and ESS 2021 publications. Values are in £ million and rounded to the nearest £5 million. 

Among international exports, transportation and storage experienced the largest percentage change, increasing by 79% from £1.3 billion in ESS 2019 to £2.4 billion in ESS 2021. Changes for all other sectors were considerably smaller and were generally decreases which balances out the change in transportation and storage, resulting in a smaller overall change for international exports.