Results from the December 2012 Scottish Agricultural Survey

4 Notes

4.1 Background

This publication contains results for the December Agricultural Survey for 2012 and includes trends for the last ten years. Where appropriate, comparisons have been made between results of the December Survey and the June Agricultural Census.

4.2 Uses of the information

The December survey is conducted for a range of purposes. The statistics help the government to form, monitor and evaluate policy, and to assess the economic well-being of the agricultural sector.

Most of the data collected is required by the Statistical Office of the European Communities, specifically Council Regulation No 1165/2008 which sets out requirements for provision of cattle, pig, sheep and goat statistics in both May/June and November/December. It defines the category, age or weight of livestock for which statistics are to be provided and specifies the provision of quarter-year or half-year production forecasts. There is also a separate EC Regulation covering the provision of winter crops. This information is collated by DEFRA for submission at member state (UK) level.

December Survey results are not as widely used as results from the June Census as the survey only covers main holdings, whereas the June Census is representative of all agricultural holdings in Scotland. However, December results supply supplementary information not available through the June census on machinery, winter livestock levels, grass sown as well as detail on hay and silage production.

Some examples detailing how the December Survey data is or has been used are:

• Estimates of Total Income From Farming (TIFF), which is used to estimate the value of agricultural productivity in Scotland. Statistics from the December Survey are used to provide estimates of livestock numbers where the production cycle occurs between each June. For example, although the June Census records the number of lambs present in Summer each year, it does not (on its own) give an indication of the volumes of finished sheep and lambs that are being processed each year. The December Survey allows us to estimate the activity and subsequent worth of sectors such as sheep, pigs and poultry.
• It is also useful to monitor livestock maintained for the next breeding season and winter crops in December so that the farming industry can better understand what to plan for in the coming year.
• The data on machinery that is collected on the December Survey is also used to help estimate some of the input costs incurred within Scottish agriculture (for example, machinery repairs, depreciation, fuel and asset worth).
• The December Survey contributes to the formulation and publication of UK statistics on agriculture. These publications are co-ordinated by DEFRA and more details are available here.
  http://www.defra.gov.uk/evidence/statistics/index.htm

Results from the December survey are available to the public as follows:

This statistical publication is available for download from the Scottish Government website along with previous releases of December Survey results:
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/PubFinalResulsDecCensus

Headline results for TIFF (mentioned above) are published each January and more detailed analysis presented in the Economic Report on Scottish Agriculture (ERSA), which is published in June of each year. Results for TIFF can be accessed as follows:
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/ResultsTIFFFBI

Economic Report on Scottish Agriculture (ERSA) is a compendium publication containing detailed statistics on Scottish agriculture, combining further information from Total Income From Farming (TIFF - see above for more details), Farm Accounts analysis (income and expenditure statistics by different farm types) and additional statistics/analysis from the June census.
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/PubEconomicReport

4.3 Methodology - data collection

The December Survey was sent to around 14,800 main holdings in 2012. These were selected using stratified random sampling where the sampling frame comprised of a list of all the main holdings in Scotland stratified by farm size and region as measured through the 2012 June Census. This spread is intended to ensure a good representation across the country and by farm size. Optimal allocation was used to calculate the sample size required in each strata in order to maximise precision of results. Following this a random sample could be selected from each strata.

The results are based on information returned from approximately 10,400 holdings, providing a response rate of 70 per cent.

4.4 Methodology - non-response

In Scotland there are around 52,600 agricultural holdings registered with the Scottish Government. We use these register details to maintain a full holding-level data set of Scottish agriculture for statistical purposes. This provides us with virtually complete coverage of agricultural activity in Scotland. However, please note that:

• we very rarely conduct a full census of holdings as this would place an unnecessary burden on farmers;
• for the selected holdings that are surveyed, not all farmers return data to us;
• where we have gaps in our holding-level data set, we 'maintain' records by producing estimates.

The December Survey is representative of main holdings (around 24,400 holdings at December 2012), which are generally those holdings over one hectare in size. Estimates are produced for those holdings which were (i) main holdings but not sampled, and (ii) surveyed but did not provide a response.

Two stages of estimation are undertaken to calculate the December results:

• For information items collected both in June Census and December Survey a trending technique is applied to estimate the current year December values. This applies to livestock items and winter crops. The holdings are divided into strata using farm size and region. Where holdings have reported for both surveys, the total change between June and December for holdings within individual stratum are calculated. These rates of change are then applied to June Census results for main holdings who were not sampled or who have not responded in December.
• For information items only collected in December such as machinery, hay/silage production and grass sown, an expansion technique is applied to estimate for the holdings we have no information for. A raising factor is calculated for each strata by counting the number of holdings in the strata and dividing it by the number of holdings a survey form was received for. These raising factors are applied to fill in for those holdings no information has been supplied for.

4.5 Methodology - future developments: Cattle Tracing System

Statistical data on cattle populations are currently collected through the June census and December survey in Scotland. In order to reduce the burden on survey respondents we plan, in future data collections, to obtain this data through the Cattle Tracing System (CTS), an administrative data source held by the British Cattle Movement Service (BCMS) which holds records of cattle numbers and movements across Great Britain. Defra have been using CTS to obtain cattle figures for England and Wales since 2007.

The table below compares cattle data collected via the 2012 December Survey with data from the CTS and shows that, over the last five years, there has been a difference of between 0.9 per cent and 2.5 per cent between the two sources.

As the December Survey only collects information on main holdings, the figures below incorporate estimates for minor holdings in order to provide a comparison of cattle figures for the whole of Scotland.

Table: Comparison of Cattle Data collected from December Survey form and from the CTS, 2008-2012

	December survey	CTS data	Difference	Percentage difference
2008	1,786,376	1,825,565	-39,189	-2.2
2009	1,764,869	1,809,329	-44,460	-2.5
2010	1,776,908	1,805,083	-28,175	-1.6
2011	1,741,035	1,757,551	-16,516	-0.9
2012	1,732,547	1,755,442	-22,895	-1.3

4.6 Data quality

Data undergo several validation processes as follows; (i) checking for any obvious errors on the paper census forms upon receipt, (ii) auto-checking and identifying any internal inconsistencies once loaded onto the initial database, (iii) auto-checking for any sudden changes in comparison with previous annual returns and other holdings, (iv) assessing any trends or switches in item areas or quantities that look unreasonable.

If necessary farmers are contacted to ensure data are correct. Additional quality assurance is provided at the later stages by utilising expert knowledge within the Scottish Government and the agriculture industry.

4.7 Main sources of bias and other error

The December Survey will be subject to measurement bias since we are reliant on farmers completing the form accurately. Ideally livestock counts should be undertaken to ascertain precise numbers of animals but, given time constraints, exact numbers of livestock are likely to be estimated. This bias will impact particularly on sub categories of livestock (e.g. weight categories for pigs or ages of cattle) rather than the total population for a livestock type. Other categories likely to be estimated by farmers include the tonnage of hay and silage produced in the year.

Guidance notes detailing what to include on the form are supplied to avoid farmers misreporting information. With regards to livestock, we require farmers to report those animals located on the holding that are either owned by the farmer or animals that are owned by someone else but are held under formal contract. It has been noted that animals are sometimes double counted in situations where animals are held under contract with both the owner of the livestock and the farmer looking after the livestock reporting the animals. To avoid this double counting we have added specific guidance on the form itself in attempt to avoid this reporting bias.

The survey may also be subject to an element of non-response bias with farmers on certain farm types being more likely to respond to the survey than others. This means that we need use older information to estimate values for farm types less likely to supply us with current information.

A stratified random sample, grouped by farm size and region, is used to select holdings for the December survey. Individual strata are sampled to different extents. However, in estimating the results we weight by strata in order to produce a full dataset and to counteract the effects of some strata being sampled to a greater degree than others. This helps to address any sampling bias that is inherent in the sample design.

4.8 Survey burden

In December 2011, a representative sample of around 110 farmers participated in a telephone survey in order to calculate the burden of participating in the December survey. It was not considered beneficial to repeat this survey this year, and but applying an RPI inflator to last year's estimate give a total compliance cost of £66,586. Please refer to the December 2011 publication for how this figure was calculated and the range of times reported^[4].

4.9 Other publications

The next large agricultural survey is the June census of agricultural holdings. This is a larger exercise which surveys around 35,000 holdings with results being published in September 2013. Results for the 2012 December survey will be released in Spring 2013.

Results from all Scottish Government agricultural surveys can be accessed here:
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/Publications

Results from previous June Censuses can be accessed here:
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/PubFinalResultsJuneCensus

Publications relating to cereal and oilseed rape production can be accessed here:
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/PubCerealHarvest

Agricultural Facts and Figures pocketbook. This provides a useful summary of the key statistics in the Scottish agriculture and food sector in a convenient pocketbook format.
http://www.scotland.gov.uk/Topics/Statistics/Browse/Agriculture-Fisheries/PubFactsFigures