coverage issues in agricultural surveys in the...
TRANSCRIPT
COVERAGE ISSUES IN AGRICULTURAL SURVEYS IN THE
REPUBLIC OF SERBIA
Karašićević Marija
Statistical Office of the Republic of Serbia
Introduction
• Statistical Farm Register (SFR)
• Sampling frames for agricultural surveys are built using the SFR
• Initial SFR was based on the Agricultural Census 2012
• Since 2014, SFR is updated using administrative data and survey data
• Issues concerning updating SFR
SFR in Statistical Office of the Republic of SerbiaSFR contains about 630 000 agricultural holdings. The register unit is
agricultural holding if it:
• cultivates (uses) 50 or more acres of agricultural land or
• less than 50 acres of agricultural land, intended for the market or
• raises no less then:• 2 heads of cattle or• 1 head of cattle and 2 heads of small animals ( pig, goat, sheep - in total) or • 5 heads of sheep or 5 heads of goat, or• 3 heads of pig, or• 4 heads of small animals or• 50 heads of poultry, or • 20 colonies of bees.
SFR in Statistical Office of the Republic of Serbia
• Administrative variables: Unique identification number (PIG), Legal status , Status (active/inactive), Address data, Unique identification number (BPG) from the Register of Agricultural Holdings of the Ministry of Agriculture , Origin of Unique identification numbers (case of merging and splitting holdings) , etc.
• Statistical variables: Cereals-total , Pulse-total , Industrial crops-total, Utilized agricultural land-total , Bovine animals-total, Pigs-total , Sheep-total, etc.
The Register of the Agricultural Holdings of the Ministry of Agriculture and Environmental Protection
• The Register of agricultural holdings of the Ministry of Agriculture and Environmental Protection contains about 450 000 registered farms and approximately 300 000 of them are active
• An important incentive for agricultural holdings to register is the fact that only registered holdings are eligible to benefit from direct state aids.
• Differences between SFR and the Register of the Ministry
Updating SFR with the Register of Agricultural HoldingsSFR is updated with data from the Register of the Ministry in February , after
conducting all agricultural surveys in previous year
• Data from the two registers are matched according to the following criteria:• Legal status
• Unique identification number (BPG) of the holding
• Unique identification number from Business Register for legal entity
• Personal identification number of holder for family holding.
• If the agricultural holding responded in sample surveys conducted in previous year and the holding is in the Register of the Ministry , survey data is used for updating SFR
Updating SFR with the Register of Agricultural Holdings
• Following administrative data and statistical variables in SFR are updated : Legal status, Status (active/inactive), address data, areas under different crops-total, bovine animals-total
• Coverage issues:
• establishing consistency of the variable definitions between relevant sources
• question what to do with the agricultural holdings in the Register of the Ministry which was not possible to link with SFR
• as merging and splitting of the agricultural holdings
Updating SFR with the Bovine Register from the Ministry of Agriculture
• Bovine Register contains:
• Data about keeper• Holding ID• Birth data of animal, Animal sex, Breed, Colure, Mother ID• Passport ID and State of birth
• Personal ID number of the holder/keeper is the only key for• matching data from the Bovine Register and SFR
• Administrative data and the number of bovine animals has been • updated in SFR
• Coverage issues
Updating SFR with the Statistical Business Register and survey data
• Unique identification number from the Business Register and main activity code are the main keys for matching data from the Register and SFR
• Once per year administrative data for agricultural holdings in SFR are updated with data from SBR
• Enterprises that are in the process of liquidation are kept in SFR
Sample based agricultural surveys in SORS
• SORS annually conducts four agricultural sample based surveys:‐Survey on Areas and Plantations at the end of Spring Sowing (May)
‐Survey on Number of Pigs (May)
‐Survey on Expected Yield of Main Late Crops, Fruits and Grapes and Total Production of Early Crops and Fruits (September)
‐Survey on Agricultural Production – Crop Production and Animal Production (December)
• In May administrative data and some statistical variables concerning land areas are updated. Number of pigs is not updated.
• In September only administrative data are updated
• In December for all sampled units administrative data and statistical variables are updated in SFR
Coverage issues and some ideas for solving them• Last three years, new holdings were added to SFR only in case existing holdings split.
One way to deal with this problem is to select a separate sample from the list of households with agricultural production which did not fulfill conditions in 2012 and to collect data on their areas and livestock during the existing agricultural surveys.
• Undercoverage problems appear in the phase of defining target population and preliminary sample frame
• Overcoverage issues: only inactive holdings with reason of inactivity “Holding ceased to exist” are excluded
Conclusion
• SFR should be a high-quality sampling frame for statistical surveys conducted inagriculture (random samples, weighting structure of the samples).
• Ensuring complete coverage is one of the main issues. It needs constant datavalidation, data quality checks on micro and macro level.
• Mismatches require careful manual examination
• Sometimes it is needed to introduce additional sample to an existing survey orintroduce a survey
