Monday, August 9, 2010

Week 19

I'm center of the range for corn, both in yields and in production. I must have a slightly higher harvest rate given my production numbers are slightly higher relative to the trade than my yields. For soybeans, again I'm in the range of trade, but in the top half.  For cotton, I don't have much trade information to compare myself to. I was well above the trade and yet spot on last month, but cotton is always tricky. I should note that in some weeks I don't have updates for New Mexico cotton conditions until after I post this, so I use last weeks conditions carried forward. This is small and doesn't effect the total much, but in case somebody out there is following New Mexico (and if so, you should know the average error for this state is probably not small).

For corn and soybeans I'm well withing the trade range so unless there is a big surprise on Thursday, I hope to be close. and as far as I can tell, I'll be closer than 1/2 the folks in 'the trade'. Note on cotton that my yield is a bit higher than USDA but I have a slightly higher abandonment rate. This abandonment rate is calculated based on condition, but yields and abandonment rates don't always move in opposite directions. If the top end of conditions stay the same but at the bottom end, some of the crop moves from poor to very poor, this may increase the abandonment rate as this area does not get harvested, but the remaining harvest crop is then on average in better condition and yields might actually rise. Given these relationships in cotton I tend to focus on the production number more. Abandonment is not nearly as volatile in corn and soybeans so the same problem does not arise here.

If you read back over the archive, the whole purpose is to construct a parsimonious model to predict yields. Something that doesn't take a lot of time and draws out the value of USDA-NASS statistics. I'll do a graphical update on Wednesday if I get new trade estimates and after the report comes out I'll do a comparison table filling in state by state USDA-NASS estimates and comparing them to my own.

Week 19 spreadsheet

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