Documentation
Data on the value of U.S. agricultural exports by State of
origin are not part of the U.S. export information collected by
U.S. Customs and Border Protection. U.S. agricultural
commodity exports are often produced in inland States and pass
through several marketing or processing points before arriving at a
port. As the commodity passes through other States before
being exported, the State-of-origin often is lost or the product
commingled with similar product from other States. Frequently, the
State from which the commodity last started its export journey, not
necessarily the State in which the commodity was produced, is the
State of origin reported by the exporter.
ERS has historically provided estimates of State agricultural
exports by allocating export values of major agricultural products
to States based on estimated State shares in U.S. production of
those products. ERS is now introducing a new series of State
export estimates in which export values are allocated to States
based on their shares of U.S. agricultural cash receipts for those
products. This new approach preserves the "origin of
production" function of the production-based allocations, but
accounts for differences in product prices and for on-farm use
across States, and uses consistent calendar year data for both U.S.
agricultural exports and U.S. farm cash receipts.
Methodology
Based on Farm Cash Receipts
Tracking export products back to their original source of
production is difficult and complicated, and information on
agricultural exports by State is not part of the data collected by
the U.S. Customs and Border Protection agency. Recording the
State of production of farm products that are exported is not
straightforward because of lack of documentation or specific source
information for processed products or mixed shipments. A large
portion of U.S. agricultural commodities, such as grains and
soybeans, are produced in inland States. Bulk commodities are
typically first sold to a local elevator, which in turn may sell
them to a larger elevator where they are mixed with similar
commodities from other States before transport to a seaport or
border crossing. Tracking the source State is even more complicated
for processed agricultural products. Processors and
manufacturers may use raw materials from a number of States, and
final processed products may undergo multiple processing steps in
different States before reaching the port for foreign shipment.
Instead of tracing commodities or products back to their original
State of production, it is more straightforward and feasible to
allocate exports by production shares, whether based on volume or
value.
Using farm production value-or cash receipts-to compute State
exports shares provides consistency because both the export values
to be estimated and farm receipts data are expressed in value
terms. With this approach, the sales revenue received by U.S.
farmers for their commodities is estimated by ERS using data on
farm cash receipts. These receipts are calculated from
production quantities and prices, or from production values, in
each U.S. State during the calendar year. The production
volume, prices, and value of agricultural commodities in each State
are estimated from farm survey data collected by USDA's National
Agricultural Statistics Service. Farm cash receipts provide
the basic information of the value of agricultural production that
is sold, whether in the domestic market or to the international
market. The national sales amount for each farm commodity
equals the sum of each State's farmgate sales receipts of that
commodity.
In order to estimate the value of a State's sales of
agricultural commodities to the international market, the share of
a commodity's farm receipts by State needs to be
determined. These shares are then applied to the U.S.
agricultural export value of that commodity. That is, a
State's estimated export value of a commodity is determined by that
State's share of the total U.S. farm receipts from sales of the
given commodity. In order to match U.S. agricultural exports
closely with farm receipts, exports are grouped as closely as
possible according to the ERS farm sales commodity groupings. This
matching is important because a State's export estimate for a
commodity, and the products processed from it, depends on the
State's share of total U.S. farm sales for that commodity.
A State's farm receipts for agricultural commodities produced
and harvested within its geographic boundaries are organized by ERS
under one of two sectors: 1) Livestock and products; and 2) Crops
and products. The livestock sector is further subdivided into meat
animals, dairy products, poultry and eggs, and miscellaneous
livestock. The crop sector consists of food grains, feed
crops, cotton, tobacco, oil crops, vegetables, fruits and nuts, and
other crops. Overall, the farm receipts-based estimates are
provided for 28 commodity groups and individual commodities.
The total farm receipts for each commodity group are the sum of the
farm receipts from all 50 States. U.S. agricultural exports,
including processed products, are summed into the same commodity
groups as are farm receipts. Estimates of State export values of a
commodity or commodity group are calculated by multiplying each
State's share of total U.S. farm receipts for that commodity or
group by the U.S. export value corresponding to the same
commodity or group.
For commodity groups that include processed products, value
added from processing can inflate the estimated export value for
that commodity group since corresponding farm receipts do not
account for processing costs. As such, the sum of estimated
exports of commodities in a group may exceed the separately
estimated export value of that commodity group. To ensure
consistency with actual U.S. agricultural export values, each
State's export estimates are calibrated to equal the actual U.S.
export values for each commodity and commodity group.
Methodology
Based on Agricultural Production
Historically, the ERS State export estimates were computed by
fiscal year and were allocated to individual States using
State-level agricultural production data supplied by the National
Agricultural Statistics Service (NASS). The underlying crop
and livestock production and slaughter estimates by State are
publicly available from NASS on their Data and Statistics page. The
State's share of production of the commodity is simply applied to
the U.S. export figure for the commodity to derive export
value. NASS does not provide production statistics for
processed agricultural products such as pasta. For these products,
supplemental data from the 2007 Census of Agriculture and the
Department of Commerce's 2002 Economic Census, Subject Series,
Manufacturing Product Summary have been used to refine State export
estimates.
The production-based estimates are provided for 20 commodity
groups, including "other." "Other" includes the many disparate
products not included elsewhere. "Other" includes wine; essential
oils; sugar and tropical products; nursery and greenhouse products;
beverages except juice; coffee; tea; cocoa; oilseeds (mostly
rapeseed and safflower seed) meals and their oils; vegetable waxes,
protein substances; chocolate; spices; rubber; fibers other than
cotton; and horticultural products, such as starches, soy sauce,
condiments, soups, gelatins, yeast, baking powder, food
preparations, vinegar and hops.
State export estimates are based on the reported State-level
production of commodities. More detailed data than appears in the
online dataset are not available. In many cases, the sum of State
production volumes is less than the reported U.S. total. This
difference is then put in an "Other States" category for each
commodity group.
ERS intends to discontinue updates of the production-based State
agricultural export estimates. Future updates will include only the
new calendar year, U.S. farm receipts-based series.
Advantages and
Weaknesses of the Methodology Based on Cash Receipts
The new agricultural cash receipts-based method for estimating
State export shares has several advantages over the
production-based system it replaces:
- Using farm cash receipts accounts for differences in quality
and price of commodities produced in each State. Information on
price per unit in each State is used in computing cash
receipts.
- Using farm cash receipts also accounts for changing farm and
export prices of farm commodities across years.
- Using farm cash receipts allows use of information on
commodities actually sold by farms rather than retained for on-farm
use. On-farm use, farm-owned stocks, and Commodity Credit
Corporation purchases are not included in farm cash receipts.
- Calendar year export value data are combined with consistent
calendar year farm cash receipts data. Using a production-based
approach requires mixing marketing year production data with Fiscal
Year export data.
The cash receipts-based methodology, however, shares several
weaknesses with a production-based approach for allocating exports
to States.
- Neither approach tracks actual movement of farm products from
States to ports or border crossings. Export estimates based on
either cash receipts or production share may differ substantially
from actual movements from States to export positions.
- Neither approach accounts for the role of States in processing
or other value addition to exported products between the farm and
export positions. The export value of processed foods and
agricultural products is apportioned to States based on where the
raw commodity is produced, not where the products were
processed. Data on value added by commodity are not available
by State. Export values (f.a.s., or "free alongside ship") also
include costs for inland freight, insurance, and other charges
incurred in delivering the commodity to the U.S. port of
exportation not attributable to the farm production of the
commodity.
- Neither approach accounts for the fact that U.S. export values
include re-exports that only pass through U.S. ports; the value of
re-exports is shared between States even though those products were
not produced in the United States.
- Neither methodology can provide information on the countries of
destination for each State's exports.
Comparison of
Production-based and Cash Receipts-based State Export
Estimates
As in exports estimated from production volumes, exports based
on values show similar States in the top rankings. The charts
below show, ranked by export earnings in 2010, the top 8 States are
California, Iowa, Illinois, Texas, Minnesota, Nebraska, Indiana,
and Kansas. These States exported from $14.9 to $4.3 billion
worth of agricultural commodities and processed products in
2010. For animal products, the largest exporters are Iowa,
Texas, California, Nebraska, and North Carolina, with earnings
ranging between $2 and $1.2 billion in 2010. The top producers
of plant products include California, Iowa, Illinois, Texas,
Minnesota, and Nebraska, whose exports range from $12.7 to $5
billion in 2010. Most of these States produce the largest
agricultural exports, including grains, oilseeds, feeds, meats,
fruits, dairy and poultry products. Overall, U.S. exports of
plant (crop) products are about 4 times more than animal products,
which confer an advantage to large grain and oilseed producing
States.
Many of these top producer States' exports exceed what their
share of farm receipts indicate. That is, about 20 States
produce highly exportable commodities resulting in their total
export estimates being larger than the value obtained from
multiplying the corresponding ratio of farm receipts by U.S.
agricultural exports. In part, the reason for this is that
value added from processing is not attributed to States that
processed those exported products, but to the States that
originally produced the primary raw materials of those
exports. Thus, States that produce much of the exported
commodities, measured as shares of farm receipts, are thus credited
with proportionally higher export values. On this point, the
production-based and receipts-based methods are compatible.
Farm cash receipts are calculated by multiplying farm production
by unit price. As such, farm receipts-based exports use the
information from commodity prices that production-based exports do
not (see
table 
). An example of how using farm sales receipts
reflect the effect of commodity prices on export estimates is the
case of rice production in Arkansas and California. Although
Arkansas produces and exports more than twice as much rice as
California according to the production-based column in the table
below, higher unit prices of California rice raise its export value
relative to Arkansas' as seen in the receipts-based column. The
export estimate for California rice based on farm receipts is $695
million in 2010, which is 73 percent of Arkansas' rice export
estimate. Thus, different prices between States for the same
commodity, as illustrated by the price premium of California rice,
will result in different export estimates if based on farm
receipts. When 2 States produce equal quantities of a commodity,
the production-based export estimates will be the same, but will
differ if their farm receipts reflect those price differences.
In the situation when two States have equal farm receipts
ratios, as between Indiana and North Carolina in 2010, their
exports estimates based on those ratios will depend on what highly
exportable commodities they produce (see table ). In this case, even though Indiana
and North Carolina have the same 3.1-percent share of total U.S.
farm cash receipts, Indiana's larger production of grain and
oilseed products relative to North Carolina, results in a larger
difference in exports estimates than what production-based exports
indicate. The results shows that the difference between export
estimates based on farm receipts is almost twice as much as that
based on production volume. That is, exports estimated from
production volume share tend to underestimate export
values. By contrast, exports based on farm receipts are more
favorable toward States from which high-value exports originate, or
toward States whose farm production is disproportionately
represented in U.S. exports.
Comparing Census
Bureau and ERS Production Share or Cash Receipts
Estimates
The U.S. Census Bureau also estimates State-level exports for
products using a method that is based on the last recorded point or
location before transport to the port of exportation. This
"origin of movement" can include either farms, silos, packers,
factories, or warehouses. State export estimates using the
Census Bureau's Origin of Movement (OM) methodology differ from
those generated by the ERS production share (PS) or cash receipts
(CR) methods (see
table ). The key difference is
that OM estimates are developed with business/manufacturing as the
focus, while the PS and CR estimates are developed with
agricultural production as the focus. For agricultural
commodities that are traditionally exported in a less-processed
form, the PS or CR estimates will lead to a larger value for States
where production occurs. For commodities that are traditionally
exported in a more highly-processed form, the OM estimates will
lead to a larger value in those States where manufacturing or
shipping occurs.
The differences are especially large for soybeans and feed
grains. In the OM series, Louisiana and Washington account for 77
percent of soybean export value. Neither of these States is in the
top 10 States in the PS/CR series. For the PS series, the top six
states account for 79 percent of soybean export value; while Iowa,
the leading PS state, and Indiana are not in the top 10 OM States.
For feed grains, Louisiana accounts for 56 percent of the OM export
value while not appearing in the top 10 PS States. Iowa, Illinois,
and Nebraska account for 54 percent of PS feed grain export value.
In the CR rankings for soybeans, the top 7 states sold 66 percent
of total soybean exports, which also exclude Louisiana or
Washington.
However, both the OM and PS/CR series list California,
Washington, and Florida as the top three states for fruit and nut
exports, with these States accounting for the majority of the
estimated values of fruit and nut exports. Together, California,
Washington, and Florida account for 81 percent of the estimated
value of fruit and nut exports using the OM methodology and for 87
percent of the estimated value of fruit and nut exports using the
PS method. These 3 states ship 79 percent of U.S. fruit exports
using cash receipts-based shares. While there is not a lot of
processing for these commodities, they are climatically suited to
these areas and substantial amounts are shipped fresh.
The bias generated by origin of movement as opposed to origin of
production or cash receipts in overestimating exports of port or
border States is addressed as well. Origin of movement has
many limitations as a substitute for origin of production for many
farm commodities and processed products, making it an inaccurate
basis for estimating State exports.
Data Sources
ERS
farm cash receipts by State and commodity are calculated from
NASS production estimates and unit prices of farm commodities in
each State:
U.S. agricultural export values are obtained from the USDA
Foreign Agricultural Service's Global Agricultural Trade System (GATS):
Farm production data by State are published by USDA's National
Agricultural Statistics Service (NASS):