Estimating Wheat Trade
The monthly estimates of U.S. wheat exports and imports are the sum of estimated exports and imports of wheat grain, wheat flour, and selected wheat products. The flour and wheat products include both food and animal feed items. Before the flour and products can be aggregated with wheat grain, these items are converted to grain-equivalent bushels--that is, the quantity of wheat grain that would have to be milled to produce that quantity of flour or wheat product.
ERS estimates export and import data for five classes of U.S. wheat: hard red winter (HRW), hard red spring (HRS), soft red winter (SRW), white, and durum. These estimates are then vetted by the various agencies in USDA's wheat Interagency Commodity Estimates Committee.
Flour and Selected Products Used in Developing the Wheat Trade Estimates
All flours, but only selected wheat products are used in estimating wheat trade quantities for total wheat and durum wheat. The selected products included in the estimates are based on relative volumes traded.
Wheat flour and selected products
HRS, durum, white winter, semolina, flour not elsewhere specified, and meal and groats Wheat flour and semolina, and meal and groats
Pasta made with eggs, pasta made without eggs, couscous, bulgur, and pellets Pasta made with eggs, pasta made without eggs, couscous, bulgur, and pellets
Durum flour and selected products
Durum flour and semolina Semolina
Pasta made without eggs and couscous
Couscous and pasta made without eggs (80 percent of this volume of this pasta is assumed to be made from durum)
The Census Bureau publishes monthly data on imports and exports of flour and wheat products. The data are categorized by the Harmonized Tariff Schedule (HTS) of the United States. For more information on HTS codes and Agricultural trade data, see Foreign Agricultural Trade of the United States (FATUS): Questions and Answers.
Converting Census Data to Grain-Equivalent Bushels
The Census Bureau trade data for grain, flour, and selected products are in metric tons (grain exports) or kilograms (flour and products). The flour and selected products are converted to grain-equivalent kilograms--i.e., the quantity of wheat grain that would have to be milled to produce one kilogram of that flour or wheat product. Then, the grain and grain-equivalent data are converted to bushels. The factors for the conversion are 2.204622 pounds per kilogram and 60 pounds per bushel.
An example calculation converting 1.0 million kilograms of flour to grain-equivalent bushels is as follows:
Step 1. Converting kilograms of flour to grain-equivalent kilograms:
1,000,000 kilograms * 1.36986 = 1,369,860 kilograms
Step 2. Converting grain-equivalent kilograms to grain-equivalent pounds:
1,369,860 kilograms * 2.204622 pounds/kilogram = 3,020,023.493 pounds
Step 3. Converting grain-equivalent pounds to grain-equivalent bushels:
3,020,023.493 pounds * 1 bushel/60 pounds = 50,334 bushels
Once all the data for flour and products are in grain-equivalent bushels, these export and import totals are then added to the data on the exports and imports of wheat grain to obtain total wheat trade estimates.
Wheat grain imported (in bushels)
+ Estimate of wheat flour imported (in grain-equivalent bushels)
+ Estimate of wheat products imported (in grain-equivalent bushels)
= Wheat import estimate
Wheat grain exported (in bushels)
+ Estimate of wheat flour exported (in grain-equivalent bushels)
+ Estimate of wheat products exported (in grain-equivalent bushels)
= Wheat export estimate
Details on the HTS codes and the conversion factors used to estimate exports and imports are provided in Excel Excel icon (16x16) spreadsheets:
Allocating Imports and Exports Across the Five Classes of Wheat
ERS allocates total imports and exports of grain and grain-equivalent bushels for flour and products across five classes of wheat to provide the data needed for supply/use analysis. The allocation methodology is different for imports and exports.
Imports. Wheat and wheat-product imports are allocated by Census category (HTS code) across the five classes using a fixed set of proportions. These proportions, by Census category, were developed in consultation with industry representatives and are shown in the Wheat class allocations rules. Excel icon (16x16)
Example: the allocation of imports of bulgur (HTS code 1904300000) is made after converting the import data to grain-equivalent bushels. Then, 25 percent of these bushels are allocated to the HRW wheat class and 75 percent to the HRS wheat class.
Exports. The durum and durum-product export allocation is taken directly from the converted Census data. Using data from USDA's Foreign Agricultural Service on export sales and donations, the remaining wheat and wheat-product exports are allocated across the other four wheat classes (HRW, HRS, SRW, and white).
An example of the methodology used to allocate non-durum exports by quarter across the other four wheat classes is as follows:
Step 1. Sum all the Census non-durum grain and converted non-durum flour and products (in grain-equivalent bushels).
242 million bushels of non-durum grain
+ 6 million grain-equivalent bushels of non-durum flour
+ 2 million grain-equivalent bushels of non-durum products
= 250 million bushels
Step 2. Sum export sales and donations for the four non-durum classes and then calculate the proportion each class composes of this total.
Export sales and donations
Share of 234 million bushels
120 million bushels
56 million bushels
30 million bushels
28 million bushels
234 million bushels
Step 3. Multiply the sum from Step 1 by the proportions calculated in Step 2 to estimate the bushels exported for each of the four classes of wheat.
HRW: 250 * .51 = 128 million bushels
HRS: 250 * .24 = 60 million bushels
SRW: 250 * .13 = 32 million bushels
White: 250 * .13 = 32 million bushels