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"The theories which I have expressed there, and which appear to you to
be so chimerical, are really extremely practical -- so practical that I depend
upon them for my bread and cheese." -- Sherlock Holmes, A Study in Scarlet
(1888)
The mysterious case of the commodity conundrum is sure to elicit passionate
debate on either side of the equation -- is the commodity boom due to speculation
or fundamentals? By the time you read this, a battle in this dispute will have
taken place on April 22, 2008 with the CFTC roundtable on agricultural markets.
Academic Mountebanks
Modern finance, or "market fundamentalism" as George Soros calls it, is based
on a little known assumption called "rational expectations equilibrium," from
which financial models are derived.
Admittedly, models are only an abstraction from reality. Expecting such models
to be exactly right is unreasonable, and it is generally understood that neoclassical
economic models have inherent limitations. Such systems are based on perfect
competition, assume that the economy is stable, and that markets naturally
return to equilibrium after a disturbance.
Hence, such models maximize utility and/or profits in a world of constraints
based on the choices of "rational" economic agents. By definition then, these
models relegate speculators to the role of that very agent which maintains
equilibrium. Hence, markets are "informationally efficient."
Paradoxically, if historical market data is assumed to represent equilibrium
and "the future is merely the statistical reflection of the past," then one
could inversely argue that perfect competition minimizes these models' usefulness
as a mechanism from which to make speculative decisions.
In other words, rational expectations compel such models to simply validate that
market price data is equated to equilibrium; unless the opposite is true --
that markets are in fact imperfect and rational expectations is untenable,
which in turn undermines the veracity of these models.
This is where post-Keynesian ideas, including the theory of reflexivity and
behavioral finance, originate. Such view takes the stance that markets are
complex, messy and uncertain, and exhibit behavioral tendencies related to
the "wisdom of crowds" and "madness of crowds." Further, economic fundamentals
and market prices create a perpetual feedback loop, each influencing the other
as well as market behavior.
Philosophically, the "rational expectationalists" believe the economy naturally
reverts to equilibrium, and seek "beta" in the wisdom of crowds; while
the "reflexive behavioralists" believe that the world persists in a state of
fluctuating disequilibrium, and seek "alpha" opportunities in the madness
of crowds.
This may be an oversimplification, but it sets the framework for the discussion
that follows...
As noted in a June 2006 U.S. Senate Staff Report by the Permanent Subcommittee
on Investigations titled, The Role of Market Speculation in Rising Oil and
Gas Prices: A Need to Put the Cop Back on the Beat, "[r]ecent academic
research indicating that commodity futures have performed as well as stocks
and better than bonds, with less risk, also has boosted expenditures on energy
commodity futures."
However, despite the proliferation of such academic studies, the buried truth
is that the academic legacy of empirical tests using a variety of asset pricing
models, including the CAPM, hedging-pressure hypothesis, or arbitrage pricing
theory, have produced inconsistent conclusions as to whether there is, in fact,
positive expected returns from speculating in the futures market. This legacy
goes back to Keynes.
So what changed in the thinking of academics, or at least mainstream perception?
The current mantra is that there are three, sometimes four, sources of return
that come from "investment" in commodities.
First, there is the "collateral yield" which references the fixed income yield
that emanates from the de minimis good faith deposit required to trade
derivatives. Second, is the "spot return," which relates to the change in pricing
of the underlying commodity -- a straight forward concept. Third, is something
called the "roll yield or return" which according to hardassetsinvestor.com
is "a bit more complicated to understand, but it is absolutely critical
to your returns." And occasionally there is reference to a fourth source,
a "strategy return," related to "how one weights and rebalances the components
of a commodity index."
Our working paper takes issue
with the concept of the roll yield/return. To begin with, the roll yield is
derived from a water-down definition of backwardation and contango, which is
based on, what Hilary Till in her book "Intelligent Commodity Investing" describes
as, the "term structure of the futures price curve." We are not alone; Erb
and Harvey (2006) also debated this notion.
This current convention then became fodder for the fantasies of various papers
including a much cited Yale University paper on commodity futures by Gorton
and Rouwenhorst (2004), proponents of the roll yield. And because this paper
is briefly mentioned by Jim Rogers in his book "Hot Commodities," a perpetuated
myth evolved around this deficient theory into the investor mindset.
Now, if one takes a close look at the studies which underlie Gorton and Rouwenhorst's
conclusion, it becomes obvious that the model they use supports a fictional
trade that cannot be duplicated in real life. Rather than rolling the futures
contract forward, they roll the futures contract backward to "prove" their
thesis. This is facilitated with the idea that the expected future spot price
is a pre-determined static constant, when in fact the "expected future spot
price," which is the lynchpin to Keynes' theory of normal backwardation, is
an unknown, to be discovered, in the future, at the time that the futures contract
converges with the spot price.
Futures contracts unlike securities are instruments with a finite life, and
terminate on pre-specified dates when the futures contract converges with the
spot price. At that point delivery of the underlying cash commodity is made
between commercial participants. A wheat futures contract, for example, has
delivery contracts for March, May, July, September and December. For this reason,
and as a matter of practice, most speculators do not allow their positions
to enter the delivery period, and a perpetual long futures position will require
a trader to "roll the contract" from one contract month to the next.
As a real world example, let's assume that a trader goes long a March futures
contract at $100, then subsequently rolls that contract 60 days later by liquidating
this contract at $120, while at the same time reentering the long position
via a July futures contract at $121. Sixty days later the trader exits the
position altogether and liquidates the July contract at $111.
The long March futures contract trade results in a $20 realized gain and the
long July futures contract trade results in a $10 realized loss. Very simply,
the net gain of $10 is then divided into the original investment amount of
$100 for a 10% return. This is straightforward and logical.
On the other hand, the model for calculating the roll yield or roll return
is not possible in the real world, but seeks to prove something on the basis
of a fictional trade.
Again, let's say that a trader goes long a March futures contract at $100,
and 60 days later liquidates the March contract at $120. The academics referred
to this as the "spot return" and the net gain of $20 is then divided into the
original investment of $100 for a 20% return.
At the same time the trader purchased the March futures contract, let us assume
that the July futures contract was trading at $90. The roll return model then
subtracts this $90 July futures contract price in the past from the
current $120 March contract liquidation price (this is not possible to facilitate
in the real world). The academics call this the "excess return" and the net
gain of $30 is then divided into the $90 July contract price (why not the $100
denominator?) for a 33% return.
As a result, the "arithmetic" roll return is equal to 33% minus 20%, which
equals 13%... Huh?
It is clear that the model aims to statistically identify an approximation
of excess returns from historical price data, but even Till (2007) states "the
convention of separating out futures-only return into spot return and roll
return is solely for performance-attribution purposes." Till additionally states
that roll returns "related to the term structure of each futures contract [is]
meaningfully so only at long investment horizons."
Present-day proponents of the roll yield also conveniently forget to mention
that Keynes et al. pointed out difficulties in empirically testing the theory
of backwardation. "Since the expected future spot price is not observable,
the signature of normal backwardation will be the tendency of the forward price
to rise (more than the opportunity costs of holding the commodity would suggest)
as the delivery date approaches."
Hypothetically, the roll return model ("simplified arbitrage theory"), which
is based on the term structure of the futures price curve and conventionally
used by present-day researchers, may indicate the possibility of backwardation
and contango conditions. However, "classical arbitrage theory," as proposed
by Keynes and his generation of researchers, related these concepts to the
relationship between a specific futures contract price and that specific
contract's "expected spot futures price," thereby invalidating the roll
return model.
Furthermore, if one is familiar with the Black-Scholes option pricing model,
roll yield/return proponents are in essence using a similar paradigm, but without
acknowledging that that the expected future spot price is not a static
constant (i.e., strike price), but rather an unknown, to be discovered, in
the future, at the time that the futures contract converges with the spot price.
Accordingly, while the term structure of the futures price curve may indicate
a potential roll return benefit or detriment, classical and simplified theory
combined results in a complex series of "roll yield permutations."
There is, in fact, an inherent flaw in the roll return model. Accordingly,
and as a direct challenge to other researchers who posit the existence
of the roll return purported from empirical tests, we argue that such structural
source of returns truly reflect leveraged returns as a function of the
model itself!
So how does classical commodity pricing theory explain concepts of backwardation
and contango? Some may dismiss the veracity of research performed by those
from the early half of the 20th century, but we suggest that the researchers
from this time, including Keynes (1930), Kaldor (1939), Hicks (1939, 1946),
Working (1948) and Brennan (1958) were more in sync with commodity fundamentals
given its relative importance in the economy at the time. Now the service industry
economy predominates.
Expanding on Kaldor's (1939) ideas about "supply-of-storage," Working (1948)
observed that since storage costs are normally higher the longer a commodity
is stored, the futures price at increasingly distant delivery dates will ordinarily
be higher than at earlier dates, and that the difference will be the cost of
storage. As a consequence, the natural slope of the term structure of the futures
price curve indicates contango, such that the spot price is below subsequent
futures prices.
This raises the question of why Keynes (1930) idea of "normal backwardation" is
assumed to be the so-called prevalent constitution of the commodity futures
market? Classical theory propositions that backwardation, which occurs when
the futures contract is priced lower than the spot price, is a result of both "congenital
weakness," the difficulty to short cash commodities, and of "convenience yield," an
indicator of scarcity.
In combination, storage cost (which includes costs such financing, insurance,
transportation, etc.) and convenience yield is expressed as the cost-of-carry,
which is derived from Kaldor's (1939) equation: futures price minus spot price
equals storage costs minus convenience yield [Ft - S0 = o - y].
Conversely, convenience yield equals spot price minus futures price plus storage
costs [y = S0 - Ft + o].
As a result, the expected spot futures price should theoretically equal the
current spot price plus the cost-of-carry [E(St) = S0 + o - y].
The funny thing is that these formulas create a problem of circular logic.
The conundrum is called "causal relativity." In order to calculate the model,
one needs a constant as a reference, but the proposed constants -- the futures
price and the spot price -- are actually variables, continually changing as
a function of the price discovery process within the commodity markets.
In fact, there is no such thing as a singular spot price at settlement. There
is a "band of spot prices" as a result of the economics (financing, storage
costs, insurance, transportation, etc.) applicable to a specific delivery location
and the grade of commodity delivered, as well as micro-economic constraints
of the commercial players involved in the transaction.
The problem is made complicated for outright speculators because they cannot
on a macro level truly know whether storage costs or convenience yield has
increased or decreased due to a change in fundamentals, or whether an arbitrage
opportunity exists because of anomaly in the cost-of-carry.
In other words, while the arbitrage model does eventually force convergence
of the futures and spot prices upon settlement, the reflexivity of these relationships
before settlement can also skew commodity price direction in one way or another
based on the combined speculative behavior of market participants.
Classical commodity theory provides different variations on the formula used
to calculate the futures, spot and convenience yield relationships. Our working
paper, in order to better frame the circular logic conundrum suggests the use
of an error term such that the formula looks like this:
Ft = S0(o ± y ± ε)t,
where Ft is the futures price, S0 is the
spot price, o is the storage outlay, ± y is the convenience
yield or inconvenience yield (a term we introduced in our working paper), and
where ± ε is a random error term with y determinable
as a separately calculated variable; or
Ft = S0(o - y · ε)t,
where ε is a random error factor from which -y can
be inferred, but is only determinable as a function of whether ε is
either ≥1, or ≤1, or whether ε equals 0, in which case
the cost-of-carry consists of storage outlay only without any convenience yield
attribute (this is a more accurate formula).
A picture is worth a thousand words and so we provide the following diagram
to reveal the reflexive interaction and complexity of these concepts. (Note:
for simplification the graphic below uses the first formula above, adding a
new variable E(St), where E(St)
equals the expected spot future price.)
The diagram illustrates how it is possible to have a positive sloping term
structure of the futures price curve, which is usually referred to as contango
market conditions, resolved to Working's (1948) empirical observations about
the relationship between futures prices and storage costs, while at the same
time also exhibit either backwardated or contango market conditions.

The central problem with forward pricing, as the diagrams reveal, is that
it is difficult for any individual speculator, much less a crowd of speculators,
to authoritatively state that the markets are backwardated or contango (which
explains the reliance on term structure). Specifically, the Sonnenschein-Mantel-Debreu
theorem raises the specter that generalized assumptions about the cost-of-carry
may be inconsistent with the intrinsic operating context and micro-economic
assumptions of an individual bona fide hedger.
In other words and as an example, ExxonMobil, because it is a bona fide hedger, is able
to determine whether the futures market is contango relative to its known storage
costs and customer requirements; likewise, Chevron-Texaco, which may have the
same or different cost-of-carry economics, can at the same time be backwardated
because the convenience yield it provides to its customers may require it to "carry
stocks beyond known immediate needs and take [its] return in general customer
satisfaction."
Hence, we posit that the conditions of backwardation and contango are actually
revealed during the period of convergence when cash commodity arbitrageurs,
such as grain elevators, take or make actual delivery against the futures contract.
This activity occurs after, partly as a function of, investors "rolling
the contract."
This technical discussion of what is driving commodity prices is of more than
academic interest. The current viability of the futures markets, whose primary
role historically has been to provide a reliable way for producers and consumers
of commodities to manage future cash flows, is now in question.
A fundamental misunderstanding of commodity market functionality by long-only "investors" has
pitted this new class of participants against "traditional" futures speculators
and commercial hedgers.
We note that in addition to fundamental reasons, there are institutional pressures
and profit incentives which lead to the invention and usage of benchmarks and
passive indices, and that modeling provides justification for creating and
bringing to market many innovative but untested "beta replication" products.
Securitized investment products based on traditional investments for the most
part are justifiable since their underlying investments are capital assets.
In addition, equity and fixed income proxies can serve a valuable purpose in
measuring traditional portfolio risk and return on a relative basis. More importantly,
why should an investor pay exorbitant fees for so-called "alpha" when that
investor can obtain the same or similar asset exposure through an inexpensive "beta" vehicle?
Innovation should not be discouraged, and in response to research and market
demand, financial institutions will continue with their efforts to securitize
all identifiable combinations of assets and replicable strategies into "exotic
beta" products, commodities included. But do these investments, often modeled
on hypothetical regression analysis and employing a predefined passive methodology,
always serve investors' best interest with respect to constructing well-diversified
portfolios? And what about broader economic policy concerns?
We contend that securitized products based on long-only exposure to commodities
will prove over time to not be the reliable and consistent source of
positive expected returns as is proposed, much less a means to properly gauge
the relative performance of speculative commodity trading. Ownership of hard
assets does not generate a yield, but a cost-of-carry, as well as commissions
to do so via forward contracts.
Commodities generally rise and fall in ranges, and the mere act of trying
to isolate a persistent source of return vis-à-vis continual ownership
but non-usage of the asset will eventually result in any previously identified source
of return slipping away. This thesis is already proving itself in the form
of generalized commodity inflation, hoarding, and declining margins/productivity
by many of the smaller commercials.
The ironic twist is that the Wall Street paradigm of multiple betas has
ported the alpha decision to the investors. If there is a persistent
source of return at this stage in the commodity bull, it is likely now being
paid by consumers (society) in the form of inflation. For this, the U.S. Treasury
is not without blame.
And what if it is a zero-sum game? How do you know if/when you are not the
greater fool? Wall Street has a bad habit of taking retail for the sucker.
Come to think of it, these ideas are not mutually exclusive.
Our research indicates that commodity pricing models have inherent shortcomings
in being able to pinpoint a definitive source of structural risk premium within
the complexity of the real world global macro economy. Further, commodity pricing
is observable materialization of behavioral finance, where risk, return, leverage
and skill operate un-tethered from the anchor of beta, such as that
which may be assumed by investors when "investing" in a commodity-linked ETF.
We hypothesize that the classic "arbitrage pricing theory" contains circular
logic, and as a consequence, its natural state is disequilibrium, not equilibrium.
We extend this hypothesis to suggest that the term structure of the futures
price curve, while indicative of a potential roll return benefit or detriment,
in fact implies a complex series of "roll yield permutations" as described
by our working paper.
Similarly, the "hedging response function" elicits a behavioral risk management
mechanism, and therefore, corroborates social reflexivity. All of these models
are inter-related, and each reflects certain qualities and dynamics within
the overall futures market paradigm.
In the final analysis, perhaps this commodity bull market may simply be a
real world incarnation of the Thomas theorem: "If men define situations as
real, they are real in their consequences."
"Life is infinitely stranger than anything which the mind of man could invent."
End of part two of a three part series.
Continue to part 3
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