Table 1. Mean Absolute Percentage Errors (MAPE) for USDA and Private Market Forecasts of Corn and Soybean Production, 1970-2004
	Corn				Soybeans
	USDA	Private			USDA	Private
	Forecast	Forecast	Difference		Forecast	Forecast	Difference
	---%---				---%---
August
1970-2004	5.2	5.4	-0.2		5.2	4.8	0.4
1970-1984	5.9	7.0	-1.1		4.9	4.8	0.1
1985-2004	4.6	4.1	0.5		5.4	4.8	0.6
September
1970-2004	4.0	4.3	-0.3		4.1	4.0	0.1
1970-1984	3.9	4.2	-0.3		3.2	3.3	-0.1
1985-2004	4.2	4.5	-0.3		4.8	4.5	0.3
October
1970-2004	2.4	3.0	-0.6		2.3	2.8	-0.4
1970-1984	2.4	3.1	-0.7		2.7	2.7	0.0
1985-2004	2.3	2.9	-0.6		2.1	2.8	-0.7
November
1970-2004	1.2	1.5	-0.4		1.4	1.5	-0.1
1970-1984	1.3	1.8	-0.4		1.8	2.1	-0.2
1985-2004	1.0	1.4	-0.4		1.1	1.1	0.0
Note: Difference is calculated as USDA minus private market.  Hence, a negative difference shows that the mean abolute error of the USDA was smaller than the mean absolute error of the private market and vice versa.