Normal Backwardation
This theory is associated with the
famous British economists John
Maynard Keynes and John Hicks.
They argued that for most com-
modities there are natural hedgers
who wish to shed risk. For exam-
ple, wheat farmers desire to shed
the risk of uncertain wheat prices.
These farmers will take short posi-
tions to deliver wheat at a guaran-
teed price; they will short hedge.
To induce speculators to take the
corresponding long positions, the
farmers need to offer them an
expectation of profit. They will
enter the long side of the contract
only if the futures price is below the
expected spot price of wheat, for
an expected profit of E ( P
T
) 2 F
0
.
The speculators’ expected profit
is the farmers’ expected loss, but
farmers are willing to bear this
expected loss to avoid the risk of uncertain wheat prices. The theory of normal backward-
ation thus suggests that the futures price will be bid down to a level below the expected spot
price and will rise over the life of the contract until the maturity date, at which point F
T
5 P
T
.
Although this theory recognizes the important role of risk premiums in futures markets,
it is based on total variability rather than on systematic risk. (This is not surprising, as
Keynes wrote almost 40 years before the development of modern portfolio theory.) The
modern view refines the measure of risk used to determine appropriate risk premiums.
Contango
The polar hypothesis to backwardation holds that the natural hedgers are the purchasers of
a commodity, rather than the suppliers. In the case of wheat, for example, we would view
grain processors as willing to pay a premium to lock in the price that they must pay for
wheat. These processors hedge by taking a long position in the futures market; therefore,
they are called long hedgers, whereas farmers are short hedgers. Because long hedgers
will agree to pay high futures prices to shed risk, and because speculators must be paid a
premium to enter the short position, the contango theory holds that F
0
must exceed E ( P
T
).
It is clear that any commodity will have both natural long hedgers and short hedgers.
The compromise traditional view, called the “net hedging hypothesis,” is that F
0
will be
less than E ( P
T
) when short hedgers outnumber long hedgers and vice versa. The strong
side of the market will be the side (short or long) that has more natural hedgers. The strong
side must pay a premium to induce speculators to enter into enough contracts to balance
the “natural” supply of long and short hedgers.
Do'stlaringiz bilan baham: |