Futures markets inefficient, speculators selling insurance to hedgers at premium.
The theory of normal backwardation suggests that futures prices for agricultural products are usually lower than the actual spot prices. This means that speculators sell insurance to hedgers, who use futures markets to avoid risks. Hedgers pay a premium to speculators for this insurance, as speculators refuse to buy contracts at the expected spot price. Studies by Telser and Cootner have tested this theory.