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Several examples on the preparation
of SUAs commodities
James Geehan,
Statistician, FAO Rome
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
2. Yield is calculated by dividing production by area:
Yield (Kg/Ha)
= Production / Area
= 4,200,000 / 1,645,000 * 1000 = 2,533 Kg/Ha
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
2. Yield is calculated by dividing production by area.
3. Feed has been estimated on the basis of information available from
the Ministry of Agriculture.
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
2. Yield is calculated by dividing production by area.
3. Feed has been estimated on the basis of information available from
the Ministry of Agriculture.
4. The quantity of wheat used for seeding has been calculated by
multiplying the estimated seeding rate with the area harvested in the
subsequent year. The seeding rate is known to be around 150Kg/Ha:
Area harvested in year t+1 = 1,750,000 Ha
Seeding rate = 150 Kg/Ha
Seeding quantity (Mt) = (1,750,000 * 150) / 1000 = 262,500 Mt
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
2. Yield is calculated by dividing production by area.
3. Feed has been estimated on the basis of information available from
the Ministry of Agriculture.
4. The quantity of wheat used for seeding has been calculated by
multiplying the estimated seeding rate with the area harvested in the
subsequent year. The seeding rate is known to be around 150Kg/Ha.
6. Waste has been estimated by industry experts to be around 5%:
Waste = Supply (Production + Imports + Stock change) * 0.05
= (4,200,000 + 50,000) * 0.05 = 212,500 Mt
Example 1 Wheat: steps to completing the SUA account
1. Area, production, imports and exports are official data. There is no
stock change.
2. Yield is calculated by dividing production by area.
3. Feed has been estimated on the basis of information available from
the Ministry of Agriculture.
4. The quantity of wheat used for seeding has been calculated by
multiplying the estimated seeding rate with the area harvested in the
subsequent year. The seeding rate is known to be around 150Kg/Ha.
5. Waste has been estimated by industry experts to be around 5%.
6. There is no information as to the direct food use of wheat or other
use. The SUA is completed by allocating the balance of the account to
processing:
Residual balance (Processing) =
(Production + Imports + Stock Change) –
(Exports + Feed + Seed + Waste + Food + Other use)
Example 2 Flour of wheat: steps to completing the SUA account
1. The quantity of Wheat processed is used as the input for the
production of Flour of Wheat.
Wheat
Flour of Wheat
Example 2 Flour of wheat: steps to completing the SUA account
1. The quantity of Wheat processed is used as the input for the
production of Flour of Wheat.
2. The production is estimated by applying an extraction rate (milling
rate in this case) of 80% as reported by industry agencies.
Flour of Wheat
Example 2 Flour of wheat: steps to completing the SUA account
1. The quantity of Wheat processed is used as the input for the
production of Flour of Wheat.
2. The production is estimated by applying an extraction rate (milling
rate in this case) of 80% as reported by industry agencies.
3. Import and export data are reported officially and entered into the
SUA.
Flour of Wheat
Example 2 Flour of wheat: steps to completing the SUA account
1. The quantity of Wheat processed is used as the input for the
production of Flour of Wheat.
2. The production is estimated by applying an extraction rate (milling
rate in this case) of 80% as reported by industry agencies.
3. Import and export data are reported officially and entered into the
SUA.
4. Waste is estimated at 3% by industry experts.
Flour of Wheat
Example 2 Flour of wheat: steps to completing the SUA account
1. The quantity of Wheat processed is used as the input for the
production of Flour of Wheat.
2. The production is estimated by applying an extraction rate (milling
rate in this case) of 80% as reported by industry agencies.
3. Import and export data are reported officially and entered into the
SUA.
4. Waste is estimated at 3% by industry experts.
5. There is no information on processing, stock change or other use.
Food is left as the residual balancing element.
Flour of Wheat
Example 3 Cow Milk: steps to completing the SUA account
1.
The SUA for Cow Milk has already been completed. We know that there
are two derived products: Cream, and Butter.
Cow Milk
Cream
Butter
Example 3 Cow Milk: steps to completing the SUA account
1.
2.
The SUA for Cow Milk has already been completed. We know that there
are two derived products: Cream, and Butter.
Cream production and extraction rate are known, so the Input can be
calculated. Waste is estimated at 2%. The residual balance is sent to
food.
Cow Milk
Cream
Butter
Example 3 Cow Milk: steps to completing the SUA account
1.
2.
3.
The SUA for Cow Milk has already been completed. We know that there
are two derived products: Cream, and Butter.
Cream production and extraction rate are known, so the Input can be
calculated. Waste is estimated at 2%. The residual balance is sent to
food.
The remaining processing can be assigned as input to Butter. Production
can then be calculated, and waste is the residual balancing element.
Cow Milk
Cream
Butter
Common problems in constructing SUAs
1. Inconsistencies between data sources, particularly between
official and non-official sources.
2. Unrealistic increases / decreases in food and calorie/fat/protein
per caput intake.
3. Statistical discrepancies – (positive or negative) imbalances in
the Supply and Utilization elements. Generally due to either
missing data or inconsistencies in the data input.
4. Lack of data or information to be able to accurately estimate
SUA elements for individual commodities.
Problem 1: Inconsistencies in the data sources
• Yield of Barley is too high, but is derived from area and production.
• Production is taken from official data; area harvested from non-official data.
• The extraction of rate (yield) of Barley is also known at 8,550 hg/Mt.
Possible solution?
• Reject the non-official figure for area harvested. The production is official
and the yield rate is known, so the area harvested can be estimated.
• Barley yield can then be adjusted automatically to more realistic levels.
Recall that:
Yield = Production / Area Harvested
If rate of Yield is known, then :
Area Harvested = Production / Yield
Problem 2: Unrealistic increases/decreases in food
• There appears to be an inconsistency in the official export data for
Tomatoes, and the level of food available for consumption.
• Food is the balancing element in the commodity. Unless the level of
food is reduced, food consumption will be too high and calorie intake
over-estimated for Tomatoes.
Possible solution?
• Modify the official Trade Data – although this is avoided whenever possible.
• Assign the export deficit to ‘Other Uses’ to match the published level of
exports.
• Food will automatically be reduced as it is the balancing element.
Problem 3: Statistical Discrepencies
• There is a statistical discrepancy in trade data of Dry Beet Pulp as a
result of an imbalance between import and export figures.
• There is an imbalance of -8(Mt) and there is no domestic production
to cover the shortfall in exports.
Possible solutions?
• The problem may be related to the data (e.g., imports for re-export may only
be counted in the export field. Or an export quantity may have been
incorrectly assigned to the wrong commodity).
• The export or import figures could be adjusted if we have more information
on the quality of the data, or how they coded in the trade commodity
classification.
• If the discrepancy is not too large, it can be ignored. There will be no effect
on per caput intake as the commodity is not sent to food.
Problem 4:
• Production and Imports cannot cover official levels of food. How
do we meet the level of utilization?
Possible solutions?
• Take from stocks to cover food levels.
• However, note whether there is trend in stocks. Continually
taking from stocks suggests there is a problem with the Supply
elements data.
Thank you for your attention