Nyborg, Karine
Working Paper
Humans in the perfectly competitive market
Memorandum, No. 02/2019
Provided in Cooperation with:
Department of Economics, University of Oslo
Suggested Citation: Nyborg, Karine (2019) : Humans in the perfectly competitive market,
Memorandum, No. 02/2019, University of Oslo, Department of Economics, Oslo
This Version is available at:
https://hdl.handle.net/10419/202631
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MEMORANDUM
No 02/2019
February 2019
Karine Nyborg
ISSN: 0809-8786
Department of Economics
University of Oslo
Humans in the perfectly competitive market
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1
Humans in the perfectly competitive market
Report from a fictional field study
Karine Nyborg
1
Abstract
The perfectly competitive market – a hypothetical situation free of market failure – serves
as a benchmark for economic theory, providing the basis for the two fundamental welfare
theorems. The radical abstractions of this idea makes it hard to grasp its full implications,
however. In this essay, I explore the perfectly competitive market using literary fiction.
Part I discusses fiction as a tool for economic theory. Part II is a science fiction story about
two economists travelling to the perfectly competitive market for their honeymoon. Part
III develops main theoretical insights emerging from the story. First, to preclude market
failure, complete social isolation must prevail. Second, the requirements of symmetric
information and no external effects are extremely hard to reconcile, leading to an
impossibility result: if trade is permitted anytime, and deliberate, welfare-relevant
learning is feasible, no perfectly competitive market can exist.
Keywords: Welfare theorems; narratives; social interaction; symmetric information; complete
contracts.
JEL codes: A11, A12, B49, D5, D60, D62, D82.
Acknowledgements: The fiction short story comprising Part II of this essay was previously published
in Norwegian (Nyborg 2016a, b), and translated to English by Rosie Hedger. I am grateful to Rosie for
her excellent translation work, and to Oslo Literary Agency for sponsoring and permitting me to
publish the translated version. The illustrations in the story are my own. Thanks to those who helped
discuss the economics of the story, its professional relevance, readability and other aspects during
and after the writing process, among them Ken Arrow, Geir Asheim, Scott Barrett, Kjell Arne Brekke,
John Broome, Carol Dasgupta, Avinash Dixit, Paul Ehrlich, Tore Ellingsen, Anke Gerber, Bård Harstad,
Aanund Hylland, Andreas Lange, Jo Thori Lind, Kai Leitemo, Espen Moen, Paul Seabright, Thomas
Sterner, Jan-Erik Støstad, Morten Støstad, Achim Voss, Brian Walker, Jim Wilen; participants in
research seminars at LAMETA Montpellier, University of Umeå, University of Gothenburg, University
of Oslo, Bank of Norway, University of Hamburg, the 39
th
Conference of the Norwegian Economists’
Association; my fiction editor Benedicte Treider, and fellow fiction writers including Jan Grue, Ola
Jørgensen, Jan Solberg, Bår Stenvik and Julianne Villanger.
1
Department of Economics, University of Oslo, P.O.Box 1095 Blindern, N-0317 Oslo. Email:
[email protected]o.
2
The word “model” sounds more scientific than “fable” or “fairytale” although I do not see
much difference between them. The author of a fable draws a parallel to a situation in real
life. He has some moral he wishes to impart to the reader. [...] Any fable can be dismissed
as being unrealistic or simplistic, but this is also the fable’s advantage.
Rubinstein (2006, p.881).
When it comes to human lives, characterized as they are by contingency and
narrativeness, stories are an indispensable way of knowing. That is why the quantitative
rigor, policy focus, and logic of economics must be supplemented with the empathy,
judgment, and wisdom that defines the humanities at their best.
Morson and Schapiro (2017, p.2).
Part I: Fiction and economic theory
Despite differences in style and content matter, economic theory has a lot in common with fiction:
since its assumptions are often chosen for reasons other than realism, economic theory is a sort of
fiction. Exploring the implications of a specific set of premises can be highly interesting in spite of – or
even because of – these premises being purely hypothetical, corresponding remotely or not at all to
the real world. The Arrow-Debreu model (Arrow and Debreu 1954) provides a prominent example of
this: no decent economist would claim that its assumptions describe the world as we know it; yet it
has become a centerpiece of economic theory.
Like the fiction writer, the economic theorist decides what rules, realistic or not, will govern the
situation being envisioned, then exploring their implications: what can and cannot happen in this
hypothetical world, given that one keeps strictly to the rules one has imposed? The language of
mathematics can be extremely useful in this endeavor. Logical errors and qualifications escaping
intuitive reasoning can be revealed by explicitly restricting the variables and mechanisms allowed to
enter into an argument, thus preventing confusion caused by excessive complexity. For the very
same reason, however, mathematical language may be less helpful in retrieving relevant implicit
knowledge – that is, intuitive but possibly unarticulated insights.
2
Below I explore, by means of literary fiction, the idea of a perfectly competitive market: a situation
completely free of market failure, satisfying the requirements of the first fundamental welfare
theorem. While the method is obviously unusual, the process of doing so turned out to reveal rather
surprising – to me, at least – economic insights.
Using verbal analysis only, abstaining from mathematics as well as professional jargon, I made no
attempt to translate the Arrow-Debreu assumptions (e.g., convex preferences) directly into the
language of fiction. Instead, I rely on a narrative often presented to beginner economics students, in
which the perfectly competitive market is defined by specific market failures being absent: no
missing markets; no market power; no asymmetric information; no external effects; no public
goods.
3
2
“Thus, presenting the problem formally, as we do in economics, seems to obscure the real-life complexity of
the situation for most students (including math students)” (Rubinstein 2006, p.879).
3
Somewhat differently specified conditions might have preserved the main intention of ensuring efficient
markets. In particular, ‘no public goods’ may be superfluous and would probably have been sufficiently covered
by ‘no external effects’ and ‘no missing markets’.
3
Exploring the implications of these requirements using the tools of storytelling revealed a surprising
impossibility result:
If i) trade is permitted at any time, ii) deliberate learning is feasible, and iii) new information may
matter for welfare, no perfectly competitive market can exist.
The present essay should not be interpreted as an attack on economic theory as such. On the
contrary, I consider the story below to be – although the form is unconventional – economic theory.
Nor do I intend to argue that economists should use the tools of literary fiction regularly in their
research. Such an exercise would not always be meaningful; moreover, being a fiction writer as well
as an economics professor, I am presumably more drawn to such attempts than most.
4
I do think, however, that economists should care about narratives – that is, the stories we tell
ourselves and others to understand the world, imposing structures on our knowledge. The story
presented below may help clarify, possibly modify, economists’ own narratives about markets,
perfect competition, and the fundamental welfare theorems.
Akerlof and Snower (2016) emphasize that narratives influence human decision-making by, e.g.,
focusing attention, shaping predictions, and establishing roles, power relations and social norms. In
games of multiple equilibria, narratives can influence equilibrium selection by shaping beliefs and
expectations. Shiller (2017) explores how contagious narratives may have set off several of the most
dramatic macroeconomic fluctuations in the past. Benabou et al. (2018) and Foerster and van der
Weele (2018a) discuss narratives as rationales for actions relating to moral or social implications;
Hillenbrand and Verrina (2018) and Foerster and van der Weele (2018b) explore this in the lab,
confirming that narratives influence generosity. Morson and Schapiro (2017a, p.1) argue that a
dialogue between economics and the humanities would enrich economics, and that novels are “not
just a literary form, but also a distinct way of understanding the social world”.
The works cited above are mostly concerned with narratives as determinants of economic behavior
in general. Shiller (2017), however, pays considerable attention to the role of the narratives of
economists in particular. The present text scrutinizes one such economist narrative by viewing it
from a very unusual angle. Economists (including myself) tend to think of the perfectly competitive
market as an intuitively simple, generally applicable, if unrealistic benchmark model, which at least
approximates certain main features of real world markets. The narrative emerging from the fiction
story below is quite different: a perfectly competitive market would have to be an astonishingly
strange and complex place.
The story proceeds in the usual way for an economic theory piece: after a brief introduction, I (or
rather, one of my characters) present the basic assumptions constituting my definition of the
perfectly competitive market for the present purpose. I then explore the hypothetical world thus
defined. To avoid complicating the story even more, I mostly ignore distributional issues. After the
story itself, Part III of my essay explores the economics insights emerging from the story in more
detail, including the impossibility result mentioned above.
Ok, off we go.
4
Fiction publications, reviews etc. are listed at karinenyborg.com.
4
Part II: Adam in the perfectly competitive market
5
I’m afraid that I’ll be disappointed, Adam thinks, that’s all.
The spacesuit is close-fitting and as rigid as a tin can, it’s too late to wipe the
sweat from his brow at this point.
In the all-encompassing suit, Susanne is hardly recognisable. Only her eyes are
visible through the open visor, as impassive as always. Adam winks at her, and with
delight he registers her winking back at him; there’s no doubting the fact that she
really has changed.
‘Are you both ready?’
The guide’s voice is loud and clear in their headset. Looking through the
protective screen, Adam meets his gaze.
‘Ready,’ he replies.
The guide turns to Susanne.
‘Ready,’ she says.
‘As mentioned previously,’ the guide says, ‘I’ll be speaking to you through your
headsets, but connection may be lost upon arrival. Return transportation departs on
schedule. Don’t be late.’
Adam waits impatiently for the visor to be sealed. He didn’t request a guide; it
was only at the insistence of the travel agency that they’d accepted one. Not that he
can blame them, he hadn’t mentioned the fact that he and Susanne are both
specialists in the field of microeconomic analysis, that they fell for one another at a
lecture on advanced consumer theory.
‘Right,’ the guide says, ‘everything should be just fine. Have a good trip!’
He turns the large lever to the right with a click. A dark shadow glides into
view, descending from above with a faint hum. Adam catches a glimpse of Susanne,
her eyes wide open, as if she feels regret, then the shadow consumes his field of vision
and everything turns black.
Susanne is never plagued by nerves.
The humming stops. The darkness is all-consuming. There isn’t a sound to be
heard.
Seemingly out of nowhere the drag begins, it tugs at him, a centrifuge, he feels
dizzy, he’s lost all sense of weight, up and down, instinctively grasping for Susanne’s
hand, where is it, where is she, how could they have chosen a honeymoon with
separate transfers?
‘Well, yes,’ the customer service agent at the central branch had confirmed,
‘you’re right, it is mentioned on our website.’
She was small with dark hair, wearing a skirt and a red blouse bearing the
firm’s logo.
5
Translated from the Norwegian by Rosie Hedger.
5
‘But to be perfectly honest,’ she continued, ‘that’s largely for promotional
purposes. To illustrate the breadth of our services, if you catch my drift. It’s rare that
we ever send anyone there.’
He looked at her. She cleared her throat.
‘We’ve never sent anyone there,’ she clarified.
She turned to Susanne and flashed her a wide smile.
‘But,’ she continued, ‘we do have lots of other very exciting options. Hogwarts
and Duckburg are our most popular destinations for the time being, particularly for
families. Couples often choose the Garden of Eden, if they’re looking for something
rural, or Valhalla, if they’re keen to visit somewhere with a little more entertainment
and party spirit. But if I really had to recommend somewhere for a honeymoon,’ she
continued, nudging Susanne’s shoulder in a familiar manner, ‘then I’d have to say,
nothing beats Lothlórien.’
Susanne crossed her arms in silence. The customer service agent’s gaze
wavered. Adam felt himself becoming uneasy; although he admired Susanne’s
tendency to ignore social codes, it was an unfortunate fact that this trait did not often
seem to improve her efficiency.
‘If it’s utopias you’re looking for,’ the customer service agent said, ‘we have
plenty of tried and tested options in that genre. What about Plato’s Ideal State? The
dictatorship of the proletariat? The latter is quite incredible.’
‘We didn’t come here to arrange to hear recommendations,’ Susanne pointed
out. ‘We came to arrange our trip.’
The customer service agent pursed her lips and studied Susanne. She turned to
Adam and took a step in his direction, partly obscuring Susanne before fixing her
gaze on him.
‘The destination isn’t properly tested,’ she said. ‘Plus…’
‘Plus what?’ Susanne asked.
‘Well,’ the customer service agent continued, her gaze still firmly set on Adam,
‘it’s really not a destination that’s at all well-suited to a honeymoon.’
I hope you are finding your transportation suitably comfortable.
The guide’s voice breaks through the darkness, more distant now, metallic-
sounding.
Welcome to this trip to the perfectly competitive market. We will now make
our way through some security procedures and kindly request your utmost
attention throughout.
The drag feels just as strong, but it’s steady, and the dizziness has subsided.
Adam’s curiosity is gradually returning. Finally, he’ll personally experience this world
that has fascinated him ever since he first embarked upon his studies, a world so
utopian that someone with his childhood experiences could scarcely believe in it, if
6
not for the fact that its existence was mathematically proven all the way back in 1954:
a society devoid of deception, suppression, coercion and intimidation.
The following is a brief summary of information received during the booking
process, and with which you should already be familiar. Our agency holds no
liability for damages caused as a result of unforeseen events during your stay.
Passengers are responsible for familiarising themselves with established practical
and cultural differences prior to arrival. Be aware that for the destination to which
you are now travelling, the cultural differences are unusually great: we do not
speak of another culture, but of no culture whatsoever.
The perfectly competitive market is among the world’s most influential
utopias. In this fictional setting, the origins of which are often attributed to Adam
Smith and his ‘invisible hand’, self-interest and social interest are one and the same
— the pursuit of one’s own narrowly selfish objectives is automatically also
considered to be in the best interests of society.
Several different versions of this utopia exist, with the following in common:
they are constructed in such a way that free trade can never be detrimental, only
beneficial. This remarkable characteristic has made the fiction a core instrument for
economic analysis. In fact, this is the very yardstick by which economists evaluate
policy: where the real world deviates from the utopia, so-called market failure,
political intervention may be necessary; where the real world aligns with the
utopia, measures are deemed unnecessary, since the perfectly competitive market
does, after all, function perfectly.
You are travelling to version 14b from our catalogue: a variety of the ‘world
without market failure’ that universities around the globe introduce to new students
of economics, and which forms a key part of every standard course in fundamental
microeconomics.
‘Hello,’ Adam calls. ‘Hello! Sorry. Please just skip all of this, we’re familiar with
it.’
Apologies. We are legally obliged to go through these points as part of our
security procedures.
‘Susanne!’ he shouts. ‘Make him stop!’
She can’t hear you.
The guide sounds irritated.
You’re interested in your own safety, I presume. Now, where were we? Oh
yes. Tourist guides are not yet available. As such, we will briefly summarise the
most important points included in the literature on this destination:
Anything of interest may be bought or sold at the market price.
Nobody can influence market prices. Everyone considers prices fixed.
There are no secrets: everyone has access to the same information.
7
External effects – influencing others, unless as part of a trade agreement – do not
exist.
Public goods, which are accessible and may be freely used by all, do not exist.
Adam groans. In spite of the overly-simplified approach to the subject, the
information rattled off by the guide is no more inspirational than the usual
introductions to its features: technical, unpoetic, lacking all perspective. Why doesn’t
he point out the fact that he’s talking about a world devoid of war, for instance?
Adam is almost compelled to rebuke him, but holds his tongue; he’s on
holiday. He knows only one person who fully understands the perfectly competitive
market, and who therefore also understands the symbolic nature of travelling
together to a world of complete and utter openness, independence and freedom, and
that person is Susanne. He thinks about the warmth of her body the previous
evening, together under the duvet, both still catching their breath, when she had said:
‘Adam. What do you think happens in the perfectly competitive market when
tourists arrive?’
‘Hmm?’
‘All of the inconsistencies. What if everything just collapses?’
‘Susanne. There are no inconsistencies. Its existence is mathematically
proven.’
‘But visitors haven’t been factored into that.’
‘Shhh.’
Adam wrapped an arm around her.
‘Does your mind ever stop going over things?’ he asked, chuckling.
Susanne rested her head on his shoulder and pulled the duvet over herself.
‘Well,’ she replied, yawning, ‘I’m sure we’ll be fine. Every world has its own
inexplicable mysteries. Death. The infinite nature of the universe.’
And then she fell asleep, her arm across his chest, her forehead resting against
his neck. But on his way home from work the next day, he had stood on the bus and
reflected on her words and had realised that it appealed to him, this idea that the
perfectly competitive market shared traits with death, with the infinite nature of the
universe. The bus crept along at snail’s pace in the direction of the crossroads, his
fellow passengers huddled tightly all around him with their accompanying sweat and
bad breath, and he realised that he would escape all of this in the perfectly
competitive market, that traffic jams and queues of any kind are classic examples of
external effects, as are sweat and bad breath. And the bus turned towards Skøyen and
his fellow passengers’ heads blocked the view through the window, but between them
he caught a momentary flash of sea, sky, sunshine twinkling on the ripples, a few
gulls soaring in the breeze high above. A trailer obscured the view, then the traffic at a
standstill dissolved; the bus inched towards the toll booth, but the image of the gulls,
so free, independent, it lingered in Adam’s mind, reminding him of their imminent
8
voyage, and of Susanne: the most astute member of the department, wonderful,
remarkable Susanne, the woman to whom he was now married, the woman who had
succumbed when he had promised her this honeymoon; and he recalls her surprise at
his suggestion, the unfamiliar softness in her expression. We’re going there
tomorrow, he thought, Susanne and I.
Much like journeys to the past, journeys to the perfectly competitive market
remain at an experimental stage.
The pull he feels is only vaguely distracting now, as if he had forgotten to eat.
Surface contact between the fiction and our world is unexplored. It is not
known whether tourists are subject to the local laws of nature and are able to adapt
to these. For instance, we do not know whether visitors instantly and automatically
gain insight into the local population’s knowledge, and, if so, if they are able to
handle such vast quantities of data.
Amateur, Adam thinks. Why should anyone know everything others do? It’s
sufficient to know what one needs to know, anything that might prove meaningful for
potential transactions.
You are now in the process of landing. We wish you a pleasant stay. Welcome
to the perfectly competitive market — happy shopping!
The drag has stopped. He feels a momentary tremor, as if from a distant
explosion; then, only intense silence.
Adam tries to turn, to look around, but the suit is too tight, too rigid, and
everything remains entirely black.
He sits in silence and waits for his visor to open; he thinks of the sea and the
gulls, of Susanne, sleeping, her cheek resting on his shoulder.
It’s strange that it should take such a long time.
Patience has never been Adam’s forte; what’s more, his scalp has started to itch, a
prickling sensation, and fairly intense at that. He longs to step out of the suit, to ruffle
his hair, to rub his palms against his cranium. Perhaps it’s much like ordinary flights:
queues to the gate, absent ground crew, baggage delays. Well, it can’t be queues, at
any rate.
‘Hello,’ he says into the microphone. ‘Sorry. Could you open up soon?’
Nobody responds. The prickling sensation doesn’t seem to be dwindling; this is
no ordinary itch, more like a buzz, a hum, like an enormous swarm of bees, creeping,
crawling, around his skull, inside of it. He’s sweating, more than before now, his
forehead, his neck, his armpits, he wants to reach for his visor and force it open, but
his arms grind to a halt as soon as he tries to move: the spacesuit is inflexible, rigid,
tightly-fitted around every last inch of him.
‘Susanne, is your visor open? Can you see anything?’
9
Adam’s mouth is dry. The prickling has spread to his throat, his eyelids, his
ears; he tries to concentrate, to take a deep breath, but it does no good, the air in the
suit is stale, spent.
‘Susanne?’
It can’t have been the intention that they should spend this long inside their
suits.
‘Hello,’ he calls out in a restrained manner. ‘I’m going to need more oxygen
soon. Can someone get me some oxygen?’
Adam recalls something the guide had said before they left, you may need this
on throughout your stay, but he can’t have been talking about the spacesuit, surely,
being sealed inside a human-shaped tin can for the duration of his honeymoon? Ha
ha.
‘Hello!’
His lips are numb. He does his best not to give in to hysteria, he’s not
hysterical, he’s just confined, blind, deaf, alone, under attack from this itch,
suffocating.
‘Let me out!’
His scream is muffled inside the snug helmet. He wants to kick, to thrash with
his arms, what’s happening to him, to Susanne, the swarm of bees rush around him,
outside of him, prickling, stinging, what kind of practical joke is this, who’s rigged
this up, why won’t anything work, why doesn’t he understand anything,
microeconomics is his field of speciality but never has he ever heard of people being
sealed inside spacesuits in the perfectly competitive market.
‘Susanne! Help!’
He’s breathing far too quickly. He needs to pull himself together. He needs to
save oxygen, this is his honeymoon, his honeymoon with Susanne; and there’s a lot to
be said about Susanne, but she’s the one for him, the one he wants to be with, he’s
dying inside this human-shaped tin can without her and the only positive in all of this
is the fact that he and Susanne managed, at least, to become husband and wife before
it was too late.
That is, if marriage entered into within a society with such primitive laws is
considered legally-binding here.
For a brief moment, he forgets to hold the swarm of bees at bay, to shield
himself from them. Terror-stricken, he feels the horde merge with his thoughts,
flooding his consciousness, submerging it; he gasps, feels something slip away, break
free – then fall into place.
An immense clear-sightedness overwhelms him.
He knows everything.
He is in the perfectly competitive market. Everything that one person knows,
he is also privy to – because what kind of information can’t be viewed as bearing
significance, directly or indirectly, for one potential transaction or another?
10
And the marriage contract with Susanne - it’s entirely incomplete! Should they
smile when they wake up? Should she step out of bed with right or left foot first? Who
should take responsibility for opening the carton of milk? How close-shaven should
he be, what compensation will he owe if he forgets to comb his hair or bestows a kiss
without the requisite degree of passion? Hardly a thing at all is specified in their
contract.
A relationship like that would be littered with external effects! All valid
contracts must be fully-specified.
He sees everything, knows everything: green peas grown by the first grade sell
for eighteen kroner per kilo, the yellowhammer’s song costs forty-four kroner per
minute, daylight is priced at fifty-eight kroner per day. Assembly-line workers are
being recruited for sector fifteen with a reimbursement of twelve kroner per hour,
depending on experience, with four kroner extra for those in good spirits, six kroner
extra for long eyelashes. The supply of young men with immaculate skin on the
marriage market is limited, the market clearing price correspondingly sky-high. Fresh
air, with immediate delivery, is available at a cost of four kroner per cubic meter.
He closes his eyes and suppresses a wheezing cough as he struggles for
perspective, to see the whole.
He can see it.
It is logical, beautiful, held together by a glorious sense of simplicity: like the
equations in the articles that he and Susanne publish (separately — she’d never
accept him as co-author, his contributions lack significance).
Of course people are sealed off from their surroundings! How else might
absolutely everything be bought or sold? The sight of frosty grass, for instance, or
misty sky, or wet asphalt, not to mention a glimpse of the sea, of the gulls: how could
such things be bought or sold at market price if passers-by could experience them for
nothing?
No: everything of potential value must be screened off from those who haven’t
paid for it.
Hence, the spacesuit – immovable, rigid, sealed off from all access to air,
sound and light.
How could it be possible that he, a researcher, has overlooked something so
obvious? He’s even requested, in his complete ignorance, to be allowed to ‘get out’, as
if there was anything resembling ‘out’ here, as if all of those things that he thinks of as
‘out’ — shared surroundings, views, light, air — aren’t actually public goods that do
not exist!
The perfectly competitive market is occlusion.
Why has nobody ever pointed this out to him? Why has he never seen it so
much as hinted at in the literature?
The outline of a diagram appears in Adam’s mind, a structure that is
marvellous in its very simplicity:
11
The diagram is schematic and, naturally, understates the number of private
properties, as well as ignoring variations in size, shape and content, ranging from
spacesuits like his own to the playgrounds of the wealthy, with marble pillars and
intricate interior architecture – but none of this is important.
The focus is the hermetic shells, the bubbles, which serve to separate each
individual. Without these, the perfectly competitive market could not exist. These are
what secure the right to property, prevent freeloading, and shield the individual from
the influence and interference of others.
And outside of these, in between them, there is but one thing, indicated by the
lines in the diagram: the flow of trade.
Trade requires transport. Free movement, for example in cars or helicopters, is
naturally quite impossible. People might crash or get in the way of others, therefore
constituting external effects; what’s more, there is no ‘out’ in which to freely move.
Physical movement occurs via conveyer tubes – flexible, hermetically sealed pipes
that can be extended or shortened, much like a telescope. The pipes extend between
properties in which trade agreements are made, against the payment of market rent
to coordinate owners along the line (‘land owners’ would be a misleading term, given
that there is no outdoors and hence no land to own).
The insight feels immense, limitless: like being on top of the world, gazing out
and seeing everything there is to see, understanding everything, like descriptions
Adam has heard of taking heroin, he’s never experienced anything like it, never felt
anything quite like it, he and Susanne will be able to talk about this for weeks, years
to come, to share memories of this vast, boundless clarity, to publish articles on it, to
Adam
12
publish together, anywhere they like, American Economic Review, Quarterly
Journal!
If they get home.
Because now he can no longer suppress his gasps, his chest aches and a high-
pitched whistling rings in his ears, and he realises that he’ll pass out before long; in
his unconscious state he’ll be unable to enter into contracts, without contracts he
won’t be able to get hold of any oxygen, what did it cost again, four kroner per cubic
meter, in the local currency, he doesn’t have any of the local currency, what does he
have to offer, assembly-line work? Himself?
Can people be sent via conveyor tubes?
Can one person make it into another’s bubble?
Yes! That’s the only way everything can be bought and sold, even services that
require a personal presence — hairdressing, sex, marriage! When several people are
together in the same room, they will naturally influence each other: contact, sound,
smell, aesthetic enjoyment or displeasure. And so to ensure that all of these elements
are considered part of trade and do not represent external effects, contracts that allow
access to another’s bubble must specify conduct, behaviour and emotional reaction to
each and every kind of situation, specified in the most minute detail.
But shared surroundings – morning light through the curtains, the scent of
green soap – aren’t these public goods that do not exist?
Well, yes and no. Are they really public goods, if access to them is a fully-
specified traded commodity?
This is a question of definition. As with other questions of definition, one
version of the perfectly competitive market exists for every alternative definition; and
fortunately, thanks to Susanne’s intervention during the booking process, Adam and
Susanne find themselves in version 14b, not 14a.
In version 14a, which happens to be the version most thoroughly explored in
Adam’s own lectures, there are no public goods, irrespective of whether access is
traded. Only now does he realise that trade in services that require personal presence
are, as a result, quite impossible. What’s more, in version 14a, mutual sensory
experiences do not exist at all. Things of that kind would be considered local public
goods, which do not exist. In version 14a, everyone is therefore eternally separated in
their own individual, hermetically-sealed bubbles.
But how, then, is it possible that everything of interest can be bought and sold?
Simply because nobody in version 14a is interested in any kind of personal contact.
In fact, version 14a of the perfectly competitive market is the mental equivalent
of a black hole: everyone possesses the same knowledge. That knowledge is therefore
a public good. But there are no public goods, and there is, therefore, no such thing as
knowledge.
The individual in version 14a of the perfectly competitive market is, therefore,
neither aware of this fact, nor anything else at all, for that matter.
13
But he and Susanne aren’t there. They are in a significantly more flexible
version, namely version 14b! And Adam has a great number of things he can sell; he
can work, he looks good – hey. Wait a minute.
What’s this?
What on earth.
It can’t be.
Is Susanne on the marriage market? Well, perhaps not all that surprising – but
with her own property?
Adam chuckles and then coughs in quick succession. How incredibly ignorant
he’s been: how little he has understood, and what a great deal he has misunderstood!
She had told him once, when he praised one of her analytical arguments, that she
comes from here: Yes, she had said, I was born and raised in the perfectly competitive
market. And he had assumed it was a joke – but has Susanne ever been in the habit of
making jokes?
This is incredible. Brilliant.
Has he misconstrued things? No. Her property has room enough for the two of
them.
Reaching an agreement is an easy matter. Her offer reflects the equilibrium
price: he’s young and he’s never had a pimple. He suggests a number of additions and
minor alterations, then accepts all of her conditions, every last detail, he doesn’t even
try to haggle, why would he haggle with her, this is exactly what he wants, this and
nothing else. He signs the contract — it’s sufficient simply to think it, a physical
signature is redundant here, where everyone possesses the same knowledge: the
entire population are immediately made aware of both the requirements and his
acceptance, should the need for verification arise.
The visor opens.
Air flows into the helmet, cool, stale, like in a cave.
He breathes deeply, quickly drawing in as much air as possible. The suit
loosens, opens.
Adam steps out cautiously. He is in a pipe, dimly-lit, tall enough that he can
stand at full height, wide enough that he can move through it, a conveyor pipe, and
not just any conveyor pipe; this pipe, pursuant to the marriage contract to which he
has just agreed, is his very own conveyor pipe: the lowest standard, with coordinate
rent covered for the first passage.
He takes a deep breath and starts walking; before long he breaks into a run.
Susanne is standing in the doorway. He can see her from a distance. The door closes
behind him once again and he’s there, inside, in her arms, her warmth, her scent,
jasmine, allspice, the fragrances of her perfume contractually stipulated, he had
always believed it to be cinnamon, but who cares, it’s the scent of Susanne.
They clasp one another with an unusual intensity, tearing one another’s
clothes off, running their fingers through one another’s hair, just as specified in their
14
contract. And the feeling of being watched, seen by everyone, can only be compared
to the time that he and Eva, the girl next door, his only childhood friend, were playing
doctors in a tent in the garden at the age of eight, the yellow afternoon sunlight
glowing through the canvas tent, and they opened the tent zip and tumbled out onto
the grass only to discover the circle of girls from their class standing outside,
laughing.
He is awoken by the sound of rain.
Adam pulls the duvet up slightly and moves closer to Susanne, as agreed upon.
She is sleeping. The sound of falling rain is true to nature; her speakers are
outstanding, and the same can be said for the rest of her equipment too, all types of
weather in refreshing combinations; temperature and oxygen levels to suit the
activity underway at any given time; clean, clear colours.
Even here in the darkness beneath the duvet, they’re with him, the thoughts of
the other seven billion inhabitants of the perfectly competitive market – just as his
thoughts are with them. It’s strange, he thinks. At home, we share our external
features but cannot share those inside of us; here things are entirely the reverse.
An incredible combination: in peace and quiet, but never alone.
He reaches out a hand and finds the control panel, lowering the volume of the
rain, turning on the windows. Clouds appear, building in form and depth, setting in
motion. The room grows lighter, and he can see the ceiling, the walls, the chest of
drawers: all these impressions legally bought and paid for.
Susanne is sleeping. She lies on her side in a light nightdress, her shoulders
brown from the sun, her hand beneath her cheek. She likes the nightdress, too; it was
the thing with the hand under her cheek that had been costly.
Fully-specified contracts covering all eventualities are incredible things; at
home he constantly had to wonder what she dreamt about, what kind of mood she
would be in when she woke up, what he should say or do.
But he needs to get up now. This is no holiday: access to Susanne’s domain
required more than simply good skin, his entire working capacity was part and parcel
of their agreement. Today’s job as an assembly-line worker has already been
arranged, with full specification of all characteristics of the workplace and every
influence of sense impressions between himself and other workers.
It’s annoying that he can’t work as an atomic physicist or a lawyer now that he
finally has the knowledge that these roles require. But unfortunately others share this
knowledge, too; moreover, the demand for lawyers is low in a society without secrets.
Adam hesitates for a second or two. He doesn’t want to get up, he wants to lie
there by Susanne’s side for just a little longer. He pulls himself together and pushes
the duvet to one side. As his feet touch the floor he feels a shudder, a subdued unrest,
like distant thunder. He looks up, taken aback; the trembling subsides, and yet
something feels different, as if the quality of the colour all around him has faded.
15
He kisses Susanne’s cheek, as agreed, and gets up. She grunts, half-asleep,
blinks a few times, then curls up in the foetal position, fists clenched beneath her
chin, her elbows poking out, before stretching, yawning.
It’s staggering, Adam thinks, that they even had to specify when and how she
would wake up, and that she really does wake up that way – nothing whatsoever
happens here by chance. The latter point is highly surprising: fieldwork is definitely
undervalued as a research method in the field of microeconomic theory.
Adam has often told his students that uncertainty and random events present
no problems in the perfectly competitive market. It’s simply a case of ensuring that
contracts are conditional, he has explained, as follows: ‘If Susanne wakes up at 07:51
and grunts, Adam should kiss her on the cheek. If she wakes at 07:52 and grunts, he
should not kiss her. If she wakes at 07:52 and does not grunt, he should kiss her
forehead,’ and so on. In such a way, even chance can be incorporated into fully-
specified contracts.
What Adam hasn’t thought about, apparently along with everyone else at
home, for that matter, is the following. Let us assume that Susanne wakes up in an
arbitrary fashion – that she pulls a face, for instance – and that Adam is standing
nearby and registers this fact. In that moment, he will know about her expression.
And, because all information is shared, everyone else will know with immediate
effect, too, this new information forced upon them without them either having asked
for or accepted it, without it having been articulated in any trade agreement: a
startling example of external effects that do not exist.
This, Adam realises, is just one more consequence of the perfectly competitive
market’s inbuilt but sadly unrecognised inconsistency: common knowledge is a public
good. Public goods do not exist.
In version 14a, the mental black hole, events can be as random as they like.
There, new information has no effect whatsoever — every individual person’s head is
entirely empty regardless. But here, in version 14b, in Susanne’s hermetically-sealed
property, every observation of unforeseen events would impose new information on
others, inside other bubbles. All privately observable events are, therefore, pre-
determined; everything there will ever be to know about these, is already known.
6
Imagine how astounded his colleagues at home will be when he points out this
fact!
6
In contrast, in a third version, 14c, the concept of chance exists, and this world is therefore not pre-determined.
All agreements that will ever be entered into are established at the beginning of time, by means of conditional
contracts (much like those Adam explained to his students). After this, no decisions of any kind are ever made.
For the rest of time, the inhabitants’ lives roll on precisely in line with those first, unalterable contracts. New
information is spread to everyone here in the same way, but it doesn’t matter, because such information can have
no influence on any transactions: there are no more transactions. Version 14c is, nevertheless, not particularly
popular as a starting point for economists’ evaluation of policy, since version 14c allows for no decisions to be
made, political or otherwise, unless one finds oneself at the beginnings of time.
16
The weather on the monitors has cleared up. The clouds are white and dainty:
fair weather clouds. In the top corner of the window image, three gulls move across
the sky, distant, lifelike.
Susanne is sitting up in bed. She smiles, running her fingers through her hair.
Adam smiles back at her, eyebrows slightly raised, as specified, Susanne, beloved
Susanne, what a relief it is to be together again, gazing at one another for a few
seconds, as stipulated in their contract, savouring the sight of her brown eyes, just a
millisecond too long.
And in that moment he feels the trembling return, like a distant rumble.
‘Adam,’ Susanne says quickly. ‘We need to talk.’
Her voice is muffled, as if there’s something wrong with the audio.
‘Talk?’ Adam repeats, surprised.
Nobody talks here. There’s no need for talking here.
‘You’re not very well-integrated, Adam,’ she says. ‘There’s a lot you just don’t
understand.’
He’s taken aback. Susanne’s hair is dishevelled, a tuft sticking out just by her
ear. Does the contract specify that?
‘And you need to understand how things work here,’ she says.
He stares at her hair; he suddenly knows precisely what she’s going to say.
‘But, Susanne,’ he stammers. ‘You can’t just throw me out. We’re married!’
‘All of your contracts are annulled.’
Her expression is blurred, unclear. Perhaps he needs spectacles.
‘You’re completely unpredictable,’ she says, a hint of frustration in her tone,
‘entirely incapable of keeping to a contract! You’re reluctant to get up in the morning!
You stare at me for too long! Why? Don’t you see that for every one of your
uncontracted whims, everyone here is shaken, shocked! What’s this?! they think, are
those two influencing each other beyond the terms of their agreement? But isn’t the
perfectly competitive market perfect? You are creating tidal waves of external effects,
over and over again!’
The colours in the room are translucent now, the contours indistinct. Adam
blinks and rubs his eyes.
‘I thought you’d be as well-integrated as I was,’ Susanne continues, ‘that you’d
fit right in, like I did in your world.’
Adam recalls the looks his colleagues had exchanged behind Susanne’s back,
the students’ petrified expressions during her lectures; he says nothing, she looks
dismayed.
‘This whole fiction is in the process of dissolving, Adam, all because of you!’
‘Me?’
Susanne throws her hands out in disdain, where is her infamous lack of
expression now? She really has changed.
17
‘Well, us, then!’ she shouts. ‘I did my bit when we came here — a one-off event!
A calculated risk! We both knew that the combination of their knowledge and ours
was bound to create a myriad of external effects the moment we landed!’
This is a thought that had never struck Adam.
Susanne stares at him, terrified.
‘Didn’t it? Really?’ she says.
Among the well-integrated, all knowledge is shared. However, quite a bit of it
is accessible to the poorly-integrated too; which is why Adam knows that it isn’t his
indifference that scares her, the fact that he had overlooked the knowledge
externalities bound to occur upon landing: his ignorance can be explained very
simply by the fact that his earthly origins have neither trained him in mind-reading,
nor in perfectly competitive market practice.
The scary part, for Susanne, is that she hadn’t registered his ignorance. And for
Susanne, born and raised in the perfectly competitive market, this can really mean
only one thing.
‘Adam, I loved you. That’s how well-integrated I was.’
He can hear the strain in her voice, her attempts to conceal that which cannot
be hidden, just as nothing can be hidden here: the fact that she’s been in exile for too
long, that she’s become integrated in another world, that she no longer fits in here.
He reaches out for her; he feels nothing, as if she’s not really there.
‘And now, for example,’ she continues, unruffled, ‘you’ve got a pimple on your
forehead. How could someone like you enter into a fully-specified contract? Someone
with no control over body or mind?’
‘Don’t you feel that way anymore?’ he whispers. ‘Don’t you love me?’
He tries to catch her eye, but he can’t, everything has become unclear, a film
out of focus.
‘But Adam. What does that mean, to love?’
She speaks slowly, condescendingly, as if to a dim-witted child. He focuses on
his shoes, bending over, trying to tie his lace.
‘To be irreplaceable to one another, perhaps?’ she suggests.
The lace is difficult to grasp; he’s lost all feeling in his fingers.
‘To be there for each other, unconditionally?’
The yellow afternoon sun glows brightly through the canvas tent, illuminating
Eva, eight years old, lighting up her smile, her bright eyes. And the buzzing around
Adam returns, it’s worse than ever, a ringing in his ears, a reverberation throughout
his brain: people young and old, male and female, from every remote corner of the
perfectly competitive market, they laugh uncontrollably, heartily, at him: the man
who believes that love is possible here, in the perfectly competitive market.
18
‘I think you’re mad,’ Susanne says, smiling and drying the corner of her eye.
‘Think for a moment. A good that isn’t for sale? Market power in the sex market?
Her words ring deep, unarticulated, slipping, like a record grinding to a halt.
He reaches out for her, wants to shout that she must come home with him, that she at
least has to lend him money for the coordinate rent, that the return transport won’t
be here for another six days. But no sound escapes his lips. Her image becomes
distorted, everything is hazy. Gravity must be out of order, too, he needs something to
hold onto, staggers towards the door, grasps the door handle, it’s not there; the cold
and smell of earth hit him all the same.
He turns. She’s gone. The door is gone. All trace of Susanne, of Susanne’s
hermetically-sealed shell, gone.
He fumbles blindly for the walls of the pipe. He finds nothing, feels nothing,
nothing beyond gasping for air, nothing beyond the sense of being devoured by an
endless, bottomless hole.
It is perfectly dark, perfectly silent.
Where is he?
What has happened?
Is he still in version 14b of the perfectly competitive market, with nobody
willing to trade with him?
Has he been sent to version 14a – the mental black hole?
Has he destroyed the perfectly competitive market for good? Is this
Armageddon?
He doesn’t know. But neither does it make any difference; for him, the
consequences are exactly the same.
19
And in the wake of this insight, another thought follows, a thought that shakes
him, casts him into existential doubt, forces him to question whether his life and all of
its work might have been based on a misunderstanding, an error.
He recalls the guide’s words: where the real world deviates from the utopia,
so-called market failure, political intervention may be necessary; where the real
world aligns with the utopia, measures are deemed unnecessary, since the perfectly
competitive market does, after all, function perfectly.
It is as if the words were lifted from one of his lectures, completely in line with
his own conviction. Until now. Because now it occurs to him that this fundamental
reasoning has, in one way or another, led him astray; though he can’t pinpoint how,
he feels that this honeymoon perhaps hasn’t been completely perfect, that it might be
nice, now, to see some kind of political intervention.
But he makes it no further than this in his thinking. This is the moment at
which the oxygen levels in Adam’s blood fall below critical levels for normal brain
function. In a flash, just as his consciousness fades, the brain’s dying synapses create
one final, lifelike notion: strangers huddle tightly all around him, he can feel the
warmth of their bodies, the smell of their sweat, their breath, and as the bus moves at
snail’s pace, he catches sight of something between their heads, blue sky, a flash of
light on the sea, a gull. And Adam’s final realisation is also his greatest: he misses the
Skøyen rush-hour traffic.
20
Part III: Discussion and conclusions
While writing the above story, I had to ask myself for every new sentence: does this break at least
one of the conditions? Almost always, the answer was ‘yes’, requiring further rewrite and search for
possible solutions. In the absence of mathematical proofs, I cannot guarantee that I have overlooked
something; nevertheless, the following is a summary of what I found.
7
Isolation
It seems impossible to escape that in a perfectly competitive market, each individual must – at least
until appropriate trade agreements have been made – be completely isolated from others.
This does not necessarily mean that people must be locked into hermetically sealed shells, like in the
story. Depriving people of all sensory abilities would also do the trick, as would being alone in the
world.
The necessity of isolation can be explained in several ways, but is related to at least three of the
listed market failures. First, if two or more individuals are together in one place, any shared
surroundings (a nice view, the color of the ceiling, noise, music, temperature, humidity, smells) – are
(local) public goods.
Second, if shared surroundings are affected in welfare-relevant ways by behaviors not internalized
through contracts with everyone present (e.g., someone has painted the ceiling), this involves
externalities, potentially affecting well-being as well as behaviors. Furthermore, any non-contracted,
welfare-relevant aspects of social interaction itself (a passer-by smiling; a person standing too close;
students looking bored during your lectures) involve externalities.
Third, isolation may be required to prevent missing markets, by ensuring that everything of interest
can be bought and sold at the market price. Isolation not only protects the individual from being
influenced by others in non-contracted ways; it also prevents others from free-riding on the
individual’s assets (e.g., enjoying a person’s beauty without paying him), allowing producers to
collect the market price.
Trade and transaction costs
If individuals were to be isolated from each other, it is not obvious how trade of physical goods, or
services involving personal presence, could take place. First, such trade would presumably require
transportation, which is typically fraught with external effects. Second, bringing suppliers and
demanders together may compromise the need for isolation discussed above.
In the story, transportation happens by means of conveyor tubes, the use of which requires payment
of a time- and location-specific market rent preventing congestion. However, this solution is rather
unsatisfactory, since it involves transaction costs. While the story itself makes no mention of
transaction cost being prohibited, allowing them would be at odds with the spirit of the Arrow-
Debreu model. If transaction costs are to be avoided, I see no other solution than teleportation.
Even with teleportation, there are obstacles: trade in any labor or other service requiring
simultaneous presence of several individuals in the same location – e.g., hairdressing, health care,
7
Readers who have not familiarized themselves with Part II may find some explanations below too brief; if so, I
recommend going back to the story, in which further explanation is provided.
21
construction teamwork – would break individuals’ isolation, thus necessarily involving local public
goods.
Hence, let us assume that public goods are allowed as long as they cannot lead to inefficient trade.
Simultaneous presence of several individuals in the same location may then be feasible, but would
require extremely detailed contracts to prevent external effects: all potentially welfare-relevant
aspects of all interactions and surroundings must be covered by fully specified contracts between
everyone present.
The troublesome inconsistency: symmetric information and no external effects
An important requirement for perfect competition is symmetric information: any information
potentially relevant for trade must be known by everyone potentially involved in that trade.
Can we limit what sort of information is relevant? This turns out to be hard. First, given that all joint
activities must be governed by fully specified contracts, almost anything could be relevant for a trade
agreement between almost anyone. Second, if some knowledge is not shared on the grounds of
being irrelevant, there would be asymmetric knowledge about what is not shared, and whether this
is indeed irrelevant.
Thus, let us proceed on the assumption that ‘no asymmetric information’ requires all knowledge to
be shared. This makes knowledge a pure public good: non-rival, non-exclusive. In the perfectly
competitive market, however, public goods do not exist.
At the outset, this makes the whole construction, as defined by the five requirements of the story,
logically inconsistent.
The fundamental problem is the following. By choosing to learn something new, the individual
creates external effects: her new knowledge is imposed on everyone else, although they may not (at
least not all of them) have agreed to (or paid for) a contract specifying this.
If, in contrast, the new information were not shared with others, the individual’s learning would
cause asymmetric information.
Uncertainty is particularly troublesome in this context. The outcomes of random events cannot be
known in advance. Hence, observing such outcomes involves new knowledge – thus leading to
information externalities.
If one insists on a strict interpretation of ‘no public goods’, this inconsistency can only be overcome if
there is no knowledge. Trying instead to resolve the inconsistency in more reasonable ways, let us
assume that any of the mentioned market failures are allowed under circumstances precluding
inefficiencies in trade. I can then see four possible solutions.
8
Solution 1: All contracts are made at the beginning of the world and cannot be renegotiated.
Learning affects others, since knowledge is a public good, but will not affect trade – since there is no
more trade.
With this solution, random events may occur and be deliberately observed, and can be handled by
means of contingent contracts. This is essentially the solution of the Arrow-Debreu model, in which
contracts are implicitly entered once and for all before the uncertainty is realized.
8
I am grateful to Ken Arrow for outlining Solutions 1 and 2 to me.
22
Solution 2: All knowledge is present at the beginning of the world, and never changes. Knowledge is a
public good, but since no learning occurs, there are no external effects.
With this solution, random events can only occur if they are not observed. Any such observations
would yield new knowledge and thus externalities. The observable world is, consequently,
predetermined.
Solution 3: New information, if it arises, matters to no-one. With this solution, learning is allowed
precisely because it is inconsequential. But if learning occurs only for matters of no concern, Solution
3 is hardly distinguishable from Solution 2. With respect to all observable and welfare-relevant
variables, the world is predetermined.
Solution 4: New information, if it arises, is provided simultaneously to everyone by nature. That is,
learning is possible, but not by individual choice. Any learning is simply a random event, involving no
externalities. Since everyone learns the same information simultaneously, information is kept
symmetric.
Whereas each of the above suggestions solves the logical inconsistency, none of them are, of course,
even slightly realistic. I summarize the above argument as follows:
Proposition 1 (the third theorem of welfare economics):
If i) trade is permitted at any time, ii) deliberate learning is possible, and iii) new information may
matter for welfare, no perfectly competitive market can exist.
In the present context, the proof can obviously be verbal only. Its logic rests on the discussion above:
under the conditions of Proposition 1, symmetric information and absence of external effects cannot
hold simultaneously.
Narratives about market efficiency
I know of no economist who claims that the real world is like the perfectly competitive market. Nor
do economists typically conduct their analyses as if this were the case: studying the implications of
asymmetric information is, for example, central in modern microeconomics.
I have, however, often heard good economists claim that the perfectly competitive market
represents an approximation to the real world, or a simplification of it. Such narratives turn out to be
rather misleading: a world with no free, spontaneous social interaction, no shared outdoors areas or
willful learning, but with free access to every other person’s thoughts, hardly resembles anything one
might experience in real life.
Obviously, my story neither disproves nor disputes previous mathematical results such as those by
Arrow and Debreu (1954), Arrow (1951), and others. The relevant question is rather whether the
assumptions underlying the two fundamental welfare theorems are consistent with the narratives of
trade in human societies economists often seem to have in mind when discussing those theorems.
Proposition 1 above points out that even in theory, a perfectly competitive market may be logically
inconsistent. In practice, it is obviously infeasible under all sorts of circumstances. We share outdoor
as well as indoor environments. Teleportation is not, as yet, possible. Humans are social animals – to
the extent that when alone, trying to think of nothing in particular, our minds are spontaneously
drawn to social relations (Lieberman 2013). Externalities, thus, are everywhere. Humans are not
mind-readers; hence asymmetric information is always present too. We form social bonds, making
23
individuals unique to each other, not easily replaced by others with similar characteristics – meaning
that market power is everywhere as well.
The first fundamental theorem of welfare economics is often presented as saying that the market
equilibrium is Pareto efficient, provided that certain assumptions are fulfilled. Given Proposition 1
above, an alternative and perhaps more helpful statement is the following: the first fundamental
theorem of welfare economics establishes that to guarantee market equilibrium efficiency,
extremely strict assumptions are needed.
Social interaction in markets
Economists’ notion of perfect competition was hardly contrived of to analyze the private family
sphere, with which my fiction story is largely preoccupied. Note, however, that this is not the source
of the story’s absurdity. Had the tale taken place in a market context, such as the factory floor or at
the hairdresser’s, it would presumably have become equally bizarre.
Absurdities arise because external effects, asymmetric information and other market failures are
integral parts of normal human interaction, shaping behavior wherever people meet and relate to
each other – within and outside of markets. The problems discussed above are thus likely to be
present in most markets, but may be of particular importance where human interaction is an
essential part of the transaction – e.g., in labor markets and markets for personal services.
Social interaction is involved in all socially learnt and culture-specific behaviors, of which many affect
markets: leadership styles, teaching styles, clothing styles, dietary customs, and so forth. Examples of
economic implications of social interaction are numerous, including conspicuous consumption
(Veblen 1899); housing market segregation (Schelling 1978); fair wage-setting (Akerlof 1980, Bewley
1998); crowding phenomena like waiting lines in restaurants (Becker 1991); customs, fads and
subcultures (Bernheim 1994); cooperation and revenge (Rabin 1993, Sobel 2005); employee
motivation (Benabou and Tirole 2003, Dur and Delfgaauw 2008, Brekke and Nyborg 2010); social
norms, conventions and coordination equilibria (Bicchieri 2006, Young 2015, Nyborg et al. 2016), to
mention some.
One aspect of social interaction that still seems understudied in economics is the phenomenon of
bonding. Precisely because it is vital to human well-being, social bonding is likely to lead to severe
inflexibility in markets such as labor and housing markets. For example, befriending one’s colleagues
bestows market power on one’s employer; similarly, landlords gain market power if their tenants, or
tenants’ children, befriend the tenants next door.
Final remarks
The fiction story about the perfectly competitive market comprising Part II of this essay proceeds
much like a standard economic theory paper: it specifies its assumptions early on, then exploring the
logical implications of those assumptions. This yields several rather surprising insights, some of which
may have been difficult to see using a more conventional approach. In particular, if trade can occur
at any time, and deliberate, potentially welfare-relevant learning is feasible, no perfectly competitive
market can exist.
Some may object that taking the assumptions of no market failure literally, like I have done here, is
unreasonable. For example, some of the external effects caused by normal social interaction may be
minor, only marginally relevant to markets. Nevertheless, adopting a flexible view of one’s
assumptions is not the usual standard in economic theory. Modifications of assumptions should be
explicit; complications cannot be dismissed by hoping that their importance is limited.
24
While representing a useful benchmark for theory, the perfectly competitive market constitutes
neither a normal nor an attractive situation. Where two or more human beings are present, market
failures will be present too – partly because what we call ‘market failures’ comprise fundamental
building blocks of normal social life. Even after appropriate redistribution, the level of social welfare
in a perfectly competitive market would presumably be extremely low, since everything that is
welfare-enhancing but might mess up market efficiency would be missing: love and friendship; parks,
forests and lakes; philharmonic concerts and soccer matches; outdoor cafes, sunny beaches. In the
perfectly competitive market, nothing is lost in free trade – but there was never all that much to lose.
The first fundamental theorem of welfare economics is often presented as saying that – in the
absence of market failures – the market equilibrium is Pareto efficient. However, if trade is permitted
at any time, deliberate learning is possible, and new information may matter for welfare, one cannot,
even in theory, exclude the presence of market failures. Another interpretation of the first
fundamental welfare theorem is, thus, that it demonstrates why markets are never guaranteed to
work efficiently.
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