I'm a consulting forester in southern Wisconsin. I'm trying to project future walnut prices in order to estimate rates of return for investments in walnut culture, and regarding cut/leave decisions in timber harvests. The basic assumption would be that the long-term future price increases would be similar to price increases over the past few decades. This rate would be combined with growth projections to arrive at a future value estimate.
Wisconsin DNR has some information (MFL program), but the gathering of data has some major problems and isn't very reliable. I had seen something from the Walnut Council many years ago which suggested an average annual increase of 2.6% over inflation, but I don't have a reference to this info any more and the Walnut Council web site didn't have any such information.
Do you have any tracking of walnut prices over the past 25-50 years, or suggestions of where such could be found?