Changes to methodology

Planned changes to methods

No methodology changes are planned for the next release, but we continuously review and improve methodology where possible. Methodology changes are also made in response to changes in data sources and data source availability.

Planned changes made in the 2025 release to methods 2018 onwards

A planned change to incorporate new data on the breakdown of part time workers available from the June Agricultural Census is applied to data from 2018 to 2025. Data presented as ‘second estimate’s in the 2024 release are now final estimates.

Methodology changes

Methodology changes are made in order to improve methodology due to improved data sources, estimations or modelling and also in response to changing availability of data sources. Where such changes are made, back series are calculated where necessary to provide good quality comparisons across the timeseries of results. Changes are also made due to to availability of data sources.

Major methodology changes

Detailed changes to methodology are included in relevant annexes. A list of all major changes from 2010 onwards is included in this section:

• Labour cost estimate methdology from 2018 onwards: A new methodology for producing labour cost estimates is included from 2018 onwards. Previous estimates were based on results from an annual survey of agricultural worker hours and earnings. This survey stopped in 2021. A new method based on results from the Farm Business Survey has replaced the need for this survey. The new method produces a slightly higher labour cost result and has been backdated to 2018 to ensure directly comparable labour results over more recent years in the total income from farming timeseries.
• Data source changes from 2021 onwards to replace the December Agricultural Survey: The December Agricultural Survey stopped in 2020. This effects a large number of different inputs to TIFF methodology, but the impact of this change varies. Livestock estimates which previously relied on December Agricultural Survey results are now more reliant on June Agricultural Census figures and estimation processes, but still provide good quality estimates. Estimates for hay and straw are now made using past trends and trends for other crops. Very limited alternative data is currently available on vehicles and machinery, and estimates are currently based on past trends while a methodology review is undertaken. Rent data has been replaced with estimates based on index data in England and Wales (Knight Frank farmland index). Detailed changes are included in relevant annexes.
• Potato price data from 2020 onwards: Potato price data for Scotland are limited. Seed prices are based on a survey of Scottish seed potato producers. This survey did not run in 2020 and collected limited responses for 2021 and 2022 estimates when the survey resumed in 2024. Seed estimates in these years are less reliable. Ware potato prices were previously based on results from the Weekly Average Price Survey (WAPS), which ceased in July 2021. Prices from 2021 onwards are based on Northern Ireland ware prices released in the Agricultural Market Reports.
• Bank advances 2020 onwards: The survey of bank advances to Scottish agriculture ceased collection of detailed bank advances data in 2019. Updated methods based on UK Finance data provide good quality estimates of total bank advances but cannot provide the level of detail previously released as part of Bank advances to Scottish agriculture statistics.
• Support payment estimates and new payments. Updated methods have resulted changes to some estimates being backdated to 2018 in the 2024 release of TIFF onwards. New support payments are also included as these arise.  
• Changes to methods 2012 onwards. A wide-ranging review of TIFF methodology was carried out during 2012 and 2013. Where changes have been made, back series were calculated where necessary.