This is a rough draft, but something to consider.

Number 1) Theoretical Maximum National Trend Yield - 171.9

Number 2) Likely Yield Range - 163.2 to 167.9

You can check out the spreadsheet table and mess around with it if you like. Do not touch the upper left hand box with the border. The other models link to it. The only adjustable variable is the progress column, don't mess with any formulas. The second page contains the scratch work for the date:yield ratio. This is just for corn, I haven't found my information for soybeans yet and I am quitting for now. There are five boxes that contain a high end run, low end run, Conan's wild guess, and theoretical maximum, which is actually impossible because it would mean we got 100% of remaining intended acres planted this week. The final box is the 2018 progress as a second model backtest. I didn't adjust for it because it was close. I based the average progress numbers off of this years reports in bold and last years average progress on the reports yet to be released. The adjustment factor of 1.06 comes from running the average progress against the trend yield. When that was performed, the predicted yield was 166.2, which is off of our trend of 176.0. So there is a raw yield and an adjusted yield. The backtest on the 2018 run showed a predicted yield of 175.2 vs the USDA yield of 176.4; so this model may skew to the low side. The adjustment should be between 5.9% and 6.5%.

Interesting thing to note: the model accounts for late planted corn decreasing yield. So inversely, if you leave more prevent plant, then the yield will rise. The model does not need to end in 100% planted, you leave the amount of intentions that you believe will be prevented. An example: if you say we plant no more corn at all and remain at the 49% and enter that number through the balance of a table. The yield will come to show 178.4; higher than trend because at that point, a greater percentage of the corn which was planted would be early, so everything is relative.

S&D Table Using Conan's Wild Guess which is 8% prevent plant

So rationing will occur under that scenario.

I will revisit this. Yield model based off the University of Illinois Data ZenFarm posted below.

2019 Corn Yield Model.xlsx (19KB - 90 downloads)