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January 2018
first month of harvesting, and thus can dif-
fer by country or region for the same crop.
USDA’s marketing year designation for a
country may differ from the one used lo-
cally – especially where crops such as rice
are harvested year round.
Aggregate world supply and demand esti-
mates represent the summation of numer-
ous local marketing years that stretch across
many months. For a given year, aggregate
world supply and demand estimates repre-
sent a concept and not a world total at one
point in time. For example, the 2017/2018
marketing year (MY) for USA corn begins on
1 September 2017 and ends 31 August 2018.
The WASDE report also includes a forecast
for the 2017/2018 production season’s corn
supply and use for South Africa, where
harvest begins in May 2018 and the mar-
keting year ends in April 2019. Since the
2018/2019 MY South African crop will
compete with the USA 2017/2018 MY crop
in world corn markets, USDA includes the
2018/2019 MY South African corn crop in
the WASDE report under the 2017/2018 MY
world totals.
The forecasting cycle for the new market-
ing year begins with projections in the May
WASDE report. NASS publishes its first
estimate of USA winter wheat production
in May and spring wheat and other small
grains production in July.
Figure 1: USDA crop estimates and forecasts organisational structure.
Figure 2: Summary of the USDA’s economic information system.