The National Agricultural Statistics Service (NASS) of the
USDA will release the first yield and production forecasts for the 2012 U.S.
corn and soybean crops on August 10. The first forecasts of the season are
always highly anticipated, but none more than this year as widespread drought
conditions have resulted in a wide range of yield and production
expectations.
It might be useful to briefly review the NASS methodology for
making corn and soybean yield and production forecasts. Data for the forecasts
are collected in two separate surveys conducted roughly in the last week of July
and the first week of August for the August report. The Agricultural Yield
Survey (AYS) queries farm operators in 32 states for corn and 29 states for
soybeans asking operators to identify the number of acres to be harvested and to
forecast the final average yield. The sample of operators is based on a
sophisticated sample design to achieve the desired sample size and each state is
expected to achieve a minimum response rate of 80 percent. In 2011,
approximately 27,000 operators were surveyed for all crops for the August
report. Each operator is surveyed in subsequent months to obtain new forecasts
of acreage and yield. Historical relationships indicate that respondents tend to
be conservative in early forecasts of final yields (underestimate yield
potential), particularly in drought years. This tendency is quantified and
factored into official yield forecasts. <Read More>
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