US Corn Yield, 1980-2010

This is a super simple plot of yields from the world's most successful crop: US corn. Yields have been trending up in steady linear fashion for a long time. The last five years are a continuation of that trend. But consider: Prices were at an all time low, in real terms around 2005-2006, trading at less than $2 bushel, and they have been above $4/bushel most of the time since late 2007. That's a solid doubling or more of prices for a sustained period of time. Now, if yields respond a lot to prices, shouldn't we see some kind of acceleration in the trend? After all, prices were pretty much falling through most of the period from 1980 to 2005, and since then have increased substantially. Like I said the other day , I sure don't "see" a big price effect on yields. Do you? There's a lot more data where this came from at www.nass.usda.gov Note that I usually don't believe "statistical significance" that cannot be seen with a compel