Commodity prices reflect the acceleration in inflation. Not a direct 1:1 correspondence.
Think second derivative from calculus.
Or, for those remedial math types, the change in slope of the curve.
For example, if inflation goes from 2% to 6%, commodities might rise by 100% or more over a short period, depending on how fast this change in inflation occurs.
Oil declined 68% from 1980 to 1998.
Did we experience 68% deflation in prices over this period ?
No, we experienced a decline in the rate of inflation.
