The author of this paper is Nick Szabo. He is polymath, computer sc...
### TL;DR - Humans evolved in small, largely self-sufficient, an...
If you want to expand on this topic here are other interested resou...
how do i take a printout of this paper?
https://en.wikipedia.org/wiki/John_Maynard_Smith
> ***"money is a formal token of delayed reciprocal altruism" *** -...
### Yap, the island of stone money Another interesting form of m...
Look up this source later.
### Fun fact: **Barter doesn't scale.** Imagine that you could ...
Some examples of valued artifacts/collectibles: ![figure 1](http...
### Velocity of money: The velocity of money corresponds to the ...
Like the fur trade rendezvous
### !Kung - Hxaro Exchange The !Kung are a hunting-gathering socie...
Seashells from the Mediterranean and Atlantic coasts have been foun...
### The Sungir children In 1955 Archaeologists discovered a 34,000...
The creation of marriage as a contract between men and women came i...
e.g. the Biblical story of Jacob (Israel) working for his brides.
Tribute may be the precursor to slavery since if you corral tribute...
### Laffer curve: The Laffer curve was first introduced introduce...
**The first coins in human history were created around 640 BC by Ki...
For a given artifact to have value and be considered as a collectib...
Not discussed here is the importance of ornamentation for signaling...
### First human collectibles Flints were likely the first human ...
#### Fiat currency: Fiat money is currency that has no intrinsic v...
Shelling Out: The Origins of Money
Nick Szabo
Originally published in 2002
The precursors of money, along with language, enabled early modern humans to solve problems
of cooperation that other animals cannot - including problems of reciprocal altruism, kin altruism,
and the mitigation of aggression. These precursors shared with non-fiat currencies very specific
characteristics - they were not merely symbolic or decorative objects.
I. MONEY
From the very start, England’s 17th century colonies in
America had a problem - a shortage of coins [D94][T01]
The British idea was to grow large amounts of tobacco,
cut timber for the ships of their global navy and merchant
marine, and so forth, sending in return the supplies they
felt were needed to keep the Americans working. In ef-
fect, early colonists were supposed to both work for the
company and shop at the company store. The investors
and the Crown much preferred this to paying in coin what
the farmers might ask, letting the farmers themselves buy
the supplies - and, heaven forbid, keep some of the profit
as well.
The colonists’ solution was at hand, but it took a few
years for them to recognize it. The natives had money,
but it was very different from the money Europeans were
used to. American Indians had been using money for mil-
lenia, and quite useful money it turned out to be for the
newly arrived Europeans - despite the prejudice among
some that only metal with the faces of their political
leaders stamped on it constituted real money. Worse,
the New England natives used neither silver nor gold.
Instead, they used the most appropriate money to be
found in their environment - durable skeleton parts of
their prey. Specifically, they used wampum, shells of the
clam venus mercenaria and its relatives, strung onto pen-
dants.
FIG. 1: Necklace of wampum. During trade the beads were
counted, removed, and re-assembled on new necklaces. Native
American shell beads were also sometimes woven into belts or
other mnemonic and ceremonial devices that demonstrated
the wealth and commitment of a tribe to a treaty.
Clams were found only at the ocean, but wampum
traded far inland. Sea-shell money of a variety of
types could be found in tribes across the American con-
tinent. The Iriquois managed to collect the largest
wampum treasure of any tribe, without venturing any-
where near the clam’s habitat.[D94] Only a handful of
tribes, such as the Narragansetts, specialized in manufac-
turing wampum, while hundreds of other tribes, many of
them hunter-gatherers, used it. Wampum pendants came
in a variety of lengths, with the number of beads propor-
tional to the length. Pendants could be cut or joined to
form a pendant of length equal to the price paid.
Once they got over their hangup about what consti-
tutes real money, the colonists went wild trading for and
with wampum. Clams entered the American vernacular
as another way to say "money". The Dutch governor of
New Amsterdram (now New York) took out a large loan
from an English-American bank - in wampum. After a
while the British authorities were forced to go along. So
between 1637 and 1661, wampum became legal tender
in New England. Colonists now had a liquid medium of
exchange, and trade in the colonies flourished.[D94]
The beginning of the end of wampum came when the
British started shipping more coin to the Americas, and
Europeans started applying their mass-manufacturing
techniques. By 1661, British authorities had thrown in
the towel, and decided it would pay in coin of the realm -
which being real gold and silver, and its minting audited
and branded by the Crown, had even better monetary
qualities than shells. In that year wampum ceased to be
legal tender in New England. In 1710 briefly became le-
gal tender in North Carolina. It continued to be used as a
medium of exchange, in some cases into the 20th century
- but its value had been inflated one hundred fold by
Western harvesting and manufacturing techniques, and
it gradually went the route that gold and silver jewelry
had gone in the West after the invention of coinage -
from well crafted money to decoration. The American
language of shell money became a quaint holdover - "a
hundred clams" became "a hundred dollars". "Shelling
out" came to mean paying in coins or bills, and eventu-
ally by check or credit card.[D94] Little did we know that
we had touched the very origins of our species.
2
II. COLLECTIBLES
Native American money took many forms besides
shells. Furs, teeth, and a variety of other objects with
properties we will discuss below were also commonly used
as media of exchange. 12,000 years ago, in what is now
Washington state, the Clovis people developed some mar-
velously long chert blades. The only problem - they break
far too easily. They were useless for cutting. The flints
were being made "for the sheer enjoyment" - or for some
other purpose that had nothing to do with cutting.[G01]
As we shall see, this seeming frivolity was, quite likely,
actually very important to their survival.
Native Americans had not, however, been the first to
make artful but useless blades, nor had they invented
shell money. Nor, for that matter, had Europeans, even
though they, too, in ages past had widely used shells
and teeth for money - not to mention cattle, gold, silver,
weapons, and much else. Asians had used all that and
faux axes issued by governments to boot, but they as
well imported this institution. For archaeologists have
found pendants of shells dating to the early Paleolithic
that could easily have substituted for Native American
money.
FIG. 2: Beads made from shells of the pea-sized snail Nas-
sarius kraussianus, that lived in a nearby estuary. Blombos
Cave, South Africa, 75,000 B.P.[B04]
In the late 1990s archaeologist Stanley Ambrose dis-
covered, in the a rock-shelter in the Rift Valley of Kenya,
a cache of beads made of ostrich eggshell, blanks, and
shell fragments. They are dated using the argon-argon
(40Ar/39Ar) ratio to at least 40,000 years old[A98].
Pierced animal teeth have been found in Spain also dat-
ing to this time.[W95] Perforated shells have also been
recovered from early Paleolithic sites in Lebanon[G95].
Recently regular shells, prepared as strung beads and
dating further back still, to 75,000 BP, have been found
in Blombos Cave in South Africa.[B04]
Our modern subspecies had migrated to Europe and
necklaces of shell and tooth appear there, from 40,000
B.P. onward. Shell and tooth pendants appear in Aus-
tralia from 30,000 B.P. onward[M93]. In all cases, the
work is highly skilled, indicating a practice that probably
FIG. 3: Ostrich-eggshell beads, Kenya Rift Valley, 40,000 B.P.
(Courtesy Stanley Ambrose)
dates much further back in time. The origin of collecting
and decorating is quite likely Africa, the original home-
land of the anatomically modern subspecies. Collecting
and making necklaces must have had an important se-
lection benefit, since it was costly - manufacture of these
shells took a great deal of both skill and time during an
era when humans lived constantly on the brink of star-
vation[C94].
Practically all human cultures, even those that do not
engage in substantial trade or that use more modern
forms of money, make and enjoy jewelry, and value cer-
tain objects more for their artistic or heirloom qualities
than for their utility. We humans collect necklaces of
shells and other kinds of jewelry - for the sheer enjoy-
ment of it. For the evolutionary psychologists an expla-
nation that humans do something for "the sheer enjoy-
ment of it" is not an explanation at all - but the posing
of a problem. Why do so many people find the collection
and wearing of jewelry enjoyable? For the evolutionary
psychologist, this question becomes - what caused this
pleasure to evolve?
FIG. 4: Detail of necklace from a burial at Sungir, Russia,
28,000 BP. Interlocking and interchangeable beads. Each
mammoth ivory bead may have required one to two hours
of labor to manufacture.[W97]
III. EVOLUTION, COOPERATION, AND
COLLECTIBLES
Evolutionary psychology starts with a key mathemat-
ical discovery of John Maynard Smith[D89]. Using mod-
3
els of populations of co-evolving genes, from the well-
developed area of population genetics, Smith posited
genes that can code for strategies, good or bad, used
in simple strategic problems (the "games" of game the-
ory). Smith proved that these genes, competing to be
propagated into future generations, will evolve strategies
that are Nash equilbria to the strategic problems pre-
sented by the competition. These games include the pris-
oner’s dilemma, a prototypical problem of cooperation,
and hawk/dove, a prototypical problem of aggression and
its mitigation.
Critical to Smith’s theory is that these strategic games,
while played out between phenotypes proximately, are in
fact games between genes the ultimate level - the level
of competition to be propagated. The genes - not nec-
essarily the individuals - influence behavior as if they
were boundedly rational (coding for strategies as opti-
mal as possible, within the limits of what phenotypes
can express given the biological raw materials and pre-
vious evolutionary history) and "selfish" (to use Richard
Dawkins’ metaphor). Genetic influences on behavior are
adaptations to the social problems presented by genes
competing through their phenotypes. Smith called these
evolved Nash equilibria evolutionary stable strategies.
The "epicycles" built on top of the earlier individual
selection theory, such as sexual selection and kin selec-
tion, disappear into this more general model which, in a
Copernican manner, puts the genes rather than individu-
als at the center of the theory. Thus Dawkins’ metaphor-
ical and often misunderstood phrase, "selfish gene", to
describe Smith’s theory.
Few other species cooperate on the order of even Pale-
olithic humans. In some cases - brood care, the colonies
of ants, termites, and bees, and so forth, animals co-
operate because they are kin - because they can help
copies of their "selfish genes" found in their kin. In some
highly constrained cases, there is also ongoing coopera-
tion between non-kin, which evolutionary psychologists
call reciprocal altruism. As Dawkins describes it[D89],
unless an exchange of favors is simultaneous (and some-
times even then), one party or the other can cheat. And
they usually do. This is the typical result of a game
theorists call the Prisoner’s Dilemna - if both parties co-
operated, both would be better off, but if one cheats, he
gains at the expense of the sucker. In a population of
cheaters and suckers, the cheaters always win. However,
sometimes animals come to cooperate through repeated
interactions and a strategy called Tit-for-Tat: start coop-
erating and keep cooperating until the other party cheats
- then defect yourself. This threat of retalation motivates
continued cooperation.
The situations where such cooperation in fact occurs
in the animal world are highly constrained. The main
constraint is that such cooperation is restricted to rela-
tionships where at least one of the participants is more or
less forced to be in the proximity of the other. The most
common case is when parasites, and hosts whose bodies
they share, evolve into symbiotes. If the interests of the
parasite and the host coincide, so that both working to-
gether would be more fit than either on their own, (i.e.
the parasite is also providing some benefit to the host),
then, if they can play a successful game of Tit-for-Tat,
they will evolve into symbiosis - a state where their in-
terests, and especially the exit mechanism of genes from
one generation to the next, coincides. They become as a
single organism. However, there is much more than coop-
eration going on here - there is also exploitation. They
occur simultaneously. The situation is ananalogous to
an institution humans would develop - tribute - which
we will analyze below.
Some very special instances occur that do not involve
parasite and host sharing the same body and evolving
into symbiotes. Rather, they involve non-kin animals
and highly constrained territory. A prominent example
Dawkins describes are cleaner fish. These fish swim in
and out of the mouths of their hosts, eating the bacteria
there, benefiting the host fish. The host fish could cheat
- it could wait for the cleaner to finish its job, then eat
it. But they don’t. Since they are both mobile, they are
both potentially free to leave the relationship. However,
the cleaner fish have evolved a very strong sense of in-
dividual territoriality, and have stripes and dances that
are difficult to spoof - much like a difficult to forge brand
logo. So the host fish know where to go to get cleaned -
and they know that if they cheat, they will have to start
over again with a new distrustful cleaner fish. The en-
trance costs, and thus the exit costs, of the relationship
are high, so that it works out without cheating. Besides,
the cleaner fish are tiny, so the benefit of eating them is
not large compared to the benefit of a small number of,
or even one, cleaning.
One of the most pertinent examples.is the vampire bat.
As their name suggests, they suck the blood of prey mam-
mals. The interesting thing is that, on a good night, they
bring back a surplus; on a bad night, nothing. Their dark
business is highly unpredictable. As a result, the lucky
(or skilled) bats often share blood with the less lucky (or
skilled) bats in their cave. They vomit up the blood and
the grateful recipient eats it.
The vast majority of these recipients are kin. Out
of 110 such regurgitations witnessed by the strong-
stomached biologist G.S. Wilkinson, 77 were cases of
mothers feeding their children, and most of the other
cases also involved genetic kin. There were, however,
a small number that could not be explained by kin al-
truism. To demonstrate these were cases of reciprocal al-
4
truism, Wilkinson combined the populations of bats from
two different groups. Bats, with very rare exception, only
fed old friends from their original group.[D89] Such coop-
eration requires building a long-term relationship, where
partners interact often, recognize each other, and keep
track of each other’s behavior. The bat cave helps con-
strain the bats into long-term relationships where such
bonds can form.
We will see that some humans, too, chose highly risky
and discontinuous prey items, and shared the resulting
surpluses with non-kin. Indeed, they accomplished this
to a far greater extent than the vampire bat. How they
did so is the main subject of our essay. Dawkins suggests,
"money is a formal token of delayed reciprocal altruism",
but then pursues this fascinating idea no further. We will.
Among small human groups, public reputation can su-
percede retaliation by a single individual to motivate
cooperation in delayed reciprocation. However, reputa-
tional beliefs can suffer from two major kinds of errors
- errors of about which person did what, and errors in
appraising the value or damages caused by that act.
The need to remember faces and favors is a major cog-
nitive hurdle, but one that most humans find relatively
easy to overcome. Recognizing faces is easy, but remem-
bering that a favor took place when such memory needs
to be recalled can be harder. Remembering the specifics
about a favor that gave it a certain value to the favored
is harder still. Avoiding disputes and misunderstandings
can be improbable or prohibitively difficult.
The appraisal or value measurement problem is very
broad. For humans it comes into play in any system of
exchange - reciprocation of favors, barter, money, credit,
employment, or purchase in a market. It is important
in extortion, taxation, tribute, and the setting of judi-
cial penalties. It is even important in reciprocal altruism
in animals. Consider monkeys exchanging favors - say
pieces of fruit for back scratches. Mutual grooming can
remove ticks and fleas that an individual can’t see or
reach. But just how much grooming versus how many
pieces of fruit constitutes a reciprocation that both sides
will consider to be "fair", or in other words not a de-
fection? Is twenty minutes of backscratching worth one
piece of fruit or two? And how big a piece?
Even the simple case of trading blood for blood is more
complicated then it seems. Just how do the bats estimate
the value of blood they have received? Do they estimate
the value of a favor by weight, by bulk, by taste, by
its ability to satiate hunger, or other variables? Just
the same, measurement complications arise even in the
simple monkey exchange of "you scratch my back and I’ll
scratch yours".
For the vast majority of potential exchanges, the mea-
surement problem is intractible for animals. Even more
than the easier problem of remembering faces and match-
ing them to favors, the ability of both parties to agree
with sufficient accuracy on an estimate of the value of a
favor in the first place is probably the main barrier to
reciprocal altruism among animals.
Just the stone tool-kit of even early Paleolithic man
that has survived for us to find was in some ways too
complicated for brains of our size. Keeping track of favors
involving them - who manufactured what quality of tool
for whom, and therefore who owed whom what, and so
on - would have been too difficult outside the boundaries
of the clan. Add onto that, quite likely, a large variety of
organic objects, ephemeral services (such as grooming),
and so on that have not survived. After even a small
fraction of these goods had been transferred and services
performed our brains, as inflated as they are, could not
possibly keep track of who owed what to whom. Today
we often write these things down - but Paleolithic man
had no writing. If cooperation occured between clans
and even tribes, as the archaeological record indicates
in fact occured, the problem gets far worse still, since
hunter-gatherer tribes were usually highly antagonistic
and mutually distrustful.
If clams can be money, furs can be money, gold can be
money, and so on - if money is not just coins or notes is-
sued by a government under legal tender laws, but rather
can be wide variety of objects - then just what is money
anyway? And why did humans, often living on the brink
of starvation, spend so much time making and enjoying
those necklaces when they could have been dong more
hunting and gathering? Nineteenth century economist
Carl Menger[M1892] first described how money evolves
naturally and inevitably from a sufficient volume of com-
modity barter. In modern economic terms the story is
similar to Menger’s.
Barter requires a coincidence of interests. Alice grows
some pecans and wants some apples; Bob grows apples
and want some pecans. They just happen to have their
orchards near each other, and Alice just happens to trust
Bob enough to wait between pecan harvest time and ap-
ple harvest time. Assuming all these conditions are met,
barter works pretty well. But if Alice was growing or-
anges, even if Bob wanted oranges as well as pecans,
they’d be out of luck - oranges and apples don ’t both
grow well in the same climate. If Alice and Bob didn’t
trust each other, and couldn’t find a third party to be a
middleman[L94] or enforce a contract, they’d also be out
of luck.
Further complications could arise. Alice and Bob can’t
fully articulate a promise to sell pecans or apples in the
future, because, among other possibilities, Alice could
keep the best pecans to herself (and Bob the best ap-
ples), giving the other the dregs. Comparing the qual-
5
ities as well as the quantities of two different kinds of
goods is all the more difficult when the state of one of
the goods is only a memory. Furthermore, neither can
anticipate events such as a bad harvest. These compli-
cations greatly add to the problem of Alice and Bob de-
ciding whether separated reciprocal altruism has truly
been reciprocal. These kinds of complications increase
the greater the time interval and uncertainty between
the original transaction and the reciprocation.
A related problem is that, as engineers would say,
barter "doesn’t scale". Barter works well at small vol-
umes but becomes increasingly costly at large volumes,
until it becomes too costly to be worth the effort. If there
are n goods and services to be traded, a barter market
requires n
2
prices. Five products would require twenty-
five prices, which is not too bad, but 500 products would
require 250,000 prices, which is far beyond what is prac-
tical for one person to keep track of. With money, there
are only n prices - 500 products, 500 prices. Money for
this purpose can work either as a medium of exchange or
simply as a standard of value - as long as the number of
money prices themselves do not grow too large to memo-
rize or change too often. (The latter problem, along with
an implicit insurance "contract", along with the lack of
a competitive market may explain why prices were often
set by long-evolved custom rather than proximate nego-
tiation).
Barter requires, in other words, coincidences of supply
or skills, preferences, time, and low transaction costs. Its
cost increases far faster than the growth in the number of
goods traded. Barter certainly works much better than
no trade at all, and has been widely practiced. But it is
quite limited compared to trade with money.
Primitive money existed long before large scale trade
networks. Money had an even earlier and more impor-
tant use. Money greatly improved the workings of even
small barter networks by greatly reducing the need for
credit. Simultaneous coincidence of preference was far
rarer than coincidences across long spans of time. With
money Alice could gather for Bob during the ripening of
the blueberries this month, and Bob hunt for Alice during
the migration of the mammoth herds six months later,
without either having to keep track of who owed who, or
trust the other’s memory or honesty. A mother’s much
greater investment in child rearing could be secured by
gifts of unforgeable valuables. Money converts the divi-
sion of labor problem from a prisoner’s dilemma into a
simple swap.
The proto-money used by many hunter-gatherer tribes
looks very different from modern money, now serves a
different role in our modern culture, and had a function
probably limited to small trade networks and other lo-
cal institutions discussed below. I will thus call such
money collectibles instead of money proper. The terms
used in the anthropological literature for such objects
are usually either "money", defined more broadly than
just government printed notes and coins but more nar-
rowly than we will use "collectible" in this essay, or the
vague "valuable", which sometimes refers to items that
are not collectibles in the sense of this essay. Reasons for
choosing the term collectible over other possible names
for proto-money will become apparent. Collectibles had
very specific attributes. They were not merely sym-
bolic. While the concrete objects and attributes val-
ued as collectible could vary between cultures, they were
far from arbitrary. The primary and ultimate evolution-
ary function of collectibles was as a medium for storing
and transfering wealth. Some kinds of collectibles, such
as wampum, could be quite functional as money as we
moderns know it, where the economic and social condi-
tions encouraged trade. I will occasionally use the terms
"proto-money" and "primitive money" interchangeably
with "collectible" when discussing pre-coinage media of
wealth transfer.
IV. GAINS FROM WEALTH TRANSFERS
People, clans or tribes trade voluntarily because both
sides believe they gain something. Their beliefs about
the value may change after the trade, for example as they
gain experience with the good or service. Their beliefs at
the time of the trade, although to some degree inaccurate
as to the value, are still usually correct as to the existence
of gain. Especially in early intertribal trade, restricted
to high value items, there was strong incentive for each
party to get their beliefs right. Thus trade almost always
did benefit both parties. Trade created value as much as
the physical act of making something.
Because individuals, clans, and tribes all vary in their
preferences, vary in their ability to satisfy these pref-
erences, and vary in the beliefs they have about these
skills and preferences and the objects that are consequent
of them, there are always gains to be made from trade.
Whether the costs of making these trades - transaction
costs - are low enough to make the trades worthwhile
is another matter. In our civilization, far more trades
are possible than were through most of human history.
Nevertheless, as we shall see some kinds of trades were
worth more than the transaction costs, for some cultures,
probably back to the beginning of homo sapiens sapiens.
Voluntary spot trades are not the only kinds of trans-
actions that benefit from lower transaction costs. This
is the key to understanding the origin and evolution of
money. Family heirlooms could be used as collateral to
remove the credit risk from delayed exchanges. The abil-
6
ity of a victorious tribe to extract tribute from the van-
quished was of great benefit to the victor . The victor’s
ability to collect tribute benefited from some of the same
kinds of transaction cost techniques as did trade. So did
the plaintiff in assessment of damages for offenses against
custom or law, and kin groups arranging a marriage. Kin
also benefited from timely and peaceful gifts of wealth by
inheritance. The major human life events that modern
cultures segregate from the world of trade benefited no
less than trade, and sometimes more so, from techniques
that lowered transaction costs. None of these techniques
was more effective, important, or early than primitive
money - collectibles.
When H. sapiens sapiens displaced H. sapiens nean-
derthalis, population explosions followed. Evidence from
the takeover in Europe, c. 40,000 to 35,000 B.P, indicates
that H. sapiens sapiens increased the carrying capacity
of its environment by a factor of ten over H. sapiens ne-
anderthalis - i.e., the population density increased ten-
fold[C94]. Not only that, the newcomers had spare time
to create the world’s first art - such as the wonderful cave
paintings, a wide variety of well crafted figurines - and of
course the wonderful pendants and necklaces of seashells,
teeth, and eggshell.
These objects were not useless decorations. Newly ef-
fective wealth transfers, made possible by collectibles as
well as other probable advance of the era, language, cre-
ated new cultural institutions that quite likely played the
leading role in the increase of carrying capacity.
The newcomers, H. sapiens sapiens, had the same size
brain, weaker bones, and smaller muscles than the Ne-
anderthals. Their hunting tools were more sophisticated,
but in 35,000 B.P. they were basically the same tools
- they were probably not even twice as effective, much
less ten times more effective. The biggest difference may
have been wealth transfers made more effective or even
possible by collectibles. H. sapiens sapiens took pleasure
from collecting shells, making jewelry out of them, show-
ing them off, and trading them. H. sapiens neanderthalis
did not. The same dynamic would have been at work,
tens of thousands of years earlier, on the Serengeti, when
H. sapiens sapiens first appeared in that dynamic mael-
strom of human evolution, Africa.
We shall describe how collectibles lowered transaction
costs in each kind of wealth transfer - in the voluntary free
gift of inheritance, in voluntary mutual trade or marriage,
and in the involuntary transfers of legal judgments and
tribute.
All these kinds of value transfer occured in many cul-
tures of human prehistory, probably from the beginning
of Homo sapiens sapiens. The gains to be made, by one
or both parties, from these major life event transfers of
wealth, were so great that they occurred despite high
transaction costs. Compared to modern money, primi-
tive money had a very low velocity - it might be trans-
ferred only a handful of times in an average individual’s
lifetime. Nevertheless, a durable collectible, what today
we would call an heirloom, could persist for many gen-
erations and added substantial value at each transfer -
often making the transfer even possible at all. Tribes
therefore often spent large amounts of time on the seem-
ingly frivolous tasks of manufacturing and exploring for
the raw materials of jewelry and other collectibles.
V. THE KULA RING
FIG. 5: The Kula trading network of pre-colonial Melane-
sia. The kula valuables doubled as "high power" money
and mnemonic for stories and gossip. Many of the goods
traded, mostly agricultural products, were available in dif-
ferent seasons, and so could not be traded in kind. Kula
collectibles solved this double-coincidence problem as an un-
forgeabaly costly, wearable (for security), and circulated (lit-
erally!) money. Necklaces circulated clockwise, and armshells
counter-clockwise, in a very regular pattern. By solving the
double-coincidence problem an armshell or necklace would
prove more valuable than its cost after only a few trades, but
could circulate for decades. Gossip and stories that about
prior owners of the collectibles further provided information
about upstream credit and liquidity. In other Neolithic cul-
tures collectibles, usually shells, circulated in a less regular
pattern but had similar purposes and attributes.[L94]