Agent-based market models

[Tom Carter]

About "barter":

  

Like-Kind Exchanges - Real Estate Tax Tips

Generally, if you exchange business or investment property solely for business or investment property of a like-kind, no gain or loss is recognized under Internal Revenue Code Section 1031. If, as part of the exchange, you also receive other (not like-kind) property or money, gain is recognized to the extent of the other property and money received, but a loss is not recognized.

Section 1031 does not apply to exchanges of inventory, stocks, bonds, notes, other securities or evidence of indebtedness, or certain other assets.

(Google is our friend:   'real estate exchage tax' yields this link:

    http://www.irs.gov/businesses/small/industries/article/0,,id=98491,00.html  )

tom

 

On Apr 12, 2009, at 9:27 PM, Russ Abbott wrote:

Nice point about money. I believe that even barter exchanges are construed as income. So there is no escape from the taxation trap except, perhaps, complete self-sufficiency.

-- Russ

On Sun, Apr 12, 2009 at 8:48 PM, Tom Carter <[hidden email]> wrote:

Russ -

  Thanks . . .

  As far as thinking about how economies "really" work . . . what follows is not really a response to your questions, but a source for thinking about transitions from subsistence/barter to a "monetized" system . . .

  A clever scheme:

    1.)  Find a region where there is a subsistence/barter "economy" (with, typically, tribal/communal shared land).

    2.)  With "high minded" fanfare, institute "land reform."  That is, divide the land up into small plots, and assign "ownership" of the plots to individuals.

    3.)  Now, the clever part:  establish a "land tax," but make sure that the "land tax" must be paid in currency.  Note that an "income tax" won't work, because then people could remain in their subsistence/barter mode, avoid having any accountable "income," and thus avoid the "taxation" trap . . .

    4.)  Before long, everyone will have to either switch to "cash crops," or engage in "wage labor" (or, more likely, both) in order to get currency to pay the "land tax."

    5.)  You will then have a "monetized" economy, together with a ready pool of "wage laborers," and "consumers" who purchase goods, since they have moved to "cash crops," away from subsistence farming.

  A quick Google search yields this essay (the Google search was:  colonial land taxation cash crop):

    http://www.cfeps.org/pubs/wp-pdf/WP25-Forstater.pdf

  A quote from the essay:  "The history of direct taxation in colonial capitalism also has some wider

theoretical implications. It shows, for example, “that ‘monetization’ did not spring forth

from barter; nor did it require ‘trust’—as most stories about the origins of money claim”

15 (Wray, 1998, p. 61). In the colonial capitalist context, money was clearly a “creature of

the state” "

  Anyway . . .

tom

On Apr 12, 2009, at 5:07 PM, Russ Abbott wrote:

Hey Tom,

Very nice work. Do you have anything that would help build intuition about how it all works? 

Also, what I'm after is an understanding of how an economy works. Your model says that an economy that satisfies certain conditions will (inevitably) wind up with a certain wealth distribution. But it doesn't tell me what's happening in the economy -- only that some people will become rich and a lot more will become poor. I'd like to develop a feeling for what's actually going on in the economy. 

For example, in my original model in which (a) each agent needs to consume one unit of each of N different resources at each time step (b) there are N agents each of which produces N units of a particular resource i (different from each agent) and (c) agents trade (barter style) units of resource one for one as needed, it seems to me that there will be no wealth accumulation. Everything that is produced is consumed, and as long as agents are able to trade with each other on a one-for-one basis, every agent survives but no agent accumulates any excess.  So that doesn't quite fit the model.

Furthermore, what happens if some agents (as a result of technological advances) are able to produce N units of a resource in less than one time step? Then those agents will have time on their hands and can produce something other than the resource that they contribute to the community. So they start producing resources that no one needs -- but that perhaps some agents want.

The agents with time on their hands then exchange these discretionary resources among each other. Again this might be modeled as a barter system -- although some convenient resource could come to serve as a unit of measure and medium of exchange. If you take this to the limit so that every agent is producing nothing but discretionary resources (i.e., the "needs" are so cheap to produce that there is no point keeping track of them), then what? In this model, every agent creates N units of value every time step. So there will never be any agents with no resources. 

In addition, since every transaction involves the exchange of units of resource of the same value, it seems like there is no room for accumulation of wealth. (This is assuming that one acquires a resource in order to consume, i.e., destroy, it.) So when two agents exchange resources, they are both left poorer since they each consume the received resource. In this model an agent grows wealthy only by not exchanging resources and keeping all the resources it produces. It then has the ability eventually to go on a shopping spree, pig out, and consume lots and lots of resources at one time.  But what else is that wealth good for in this economy?

So all this doesn't quite seem to fit the model you are describing.

-- Russ

On Sun, Apr 12, 2009 at 4:31 PM, Tom Carter <[hidden email]> wrote:

All -

  The real "random walks" link:

  http://csustan.csustan.edu/~tom/SFI-CSSS/2009/LectureNotes/Random%20Walk/

tom

On Apr 12, 2009, at 3:58 PM, Tom Carter wrote:

All -

  Apropos some of this, there are notes from lectures I've given recently on some of these topics here:

  Math Club lecture  (including some discussion of the "wealth model," and some "power laws" discussion)

  Black-Scholes/High Finance

  Random Walks

tom

On Apr 12, 2009, at 11:16 AM, Stephen Guerin wrote:

Russ writes:

there are N agents; N resources are needed for survival. So if the aggregate production is evenly distributed everyone has a subsistence living.

I don't think this is necessarily true.

Your mentioning a gift economy is further a reason to look at a model as simple as the Tom Carter/Victor Yakovenko model I mentioned where agents are giving a dollar to another random agent (ie gifting). This model, with minimal assumptions, generates non-equitable distribution of wealth where very few agents end up holding most of the wealth (Boltzmann distribution) even though the average wealth in the model is unchanged at $50/agent.

The important constraint in the model is that agents can only have positive amounts of cash/goods -- they can't gift a dollar they don't have.

Just as energy distributes itself as a boltzmann distribution as particles can not have less than zero energy after a collision (transaction). Basically we have diffusion against a wall in both models. Of course we can introduce debt and progressive taxes to the economic model to mess with the dynamics, but I think it's important to recognize the non-equity is there from the beginning with very minimal assumptions. Note that the wealthy agents do turnover in this model so the definition of what is equitable is important.

-Steve



On Apr 12, 2009, at 11:40 AM, Russ Abbott wrote:

Thanks for all the responses.  What prompted my question was thinking about the "end state" of the current financial crisis.  The question is: what does a successful stable economy look like? Only secondarily was I asking about markets, wealth distribution across society, etc., which is what many of the existing models focus on.

In attempting to describe the foundations of a stable economy I was making the following assumptions.

• We live off the gift of free energy -- the sun. So in some sense a stable economy requires little more than harvesting that energy.

• As human beings we have the innate (i.e., also free) ability to transform that energy into other forms that we need. For example, most of us on this list are capable of writing code. I'm taking skills like that as more free gifts from nature. Yes, it requires, education, study, practice, etc., but ultimately it grows out of our being alive, a free gift.

• In talking about "free gifts" from nature, I'm not trying to be spiritual, new age-y, etc. It just seems to me to be the way the world works. So I'm willing to build it into the model.

• But, even though we live off these free gifts, we all need energy to survive. If you look at my "Reductionist blind spot" paper, you see that we are what I call dynamic entities. Dynamic entities need to import externally supplied energy to persist -- in our case food, at least. So even though we find ourselves in a world in which there is externally supplied energy available to be imported (from the sun and its stored versions), we are each still required to do something to import it for ourselves. That is, we must each work for a living.

• Presumably a standard economic model says that we live at a subsistence level if the amount of work we do matches our needs. If I spend all my working hours doing nothing more than earning what I need to survive, that's subsistence.

• I want to allow specialization so I suggested that each agent specializes in producing some resource but that the aggregate amount produced exactly satisfies the needs of the producers. That is, each agent produces N units of his specialty resource; there are N agents; N resources are needed for survival. So if the aggregate production is evenly distributed everyone has a subsistence living.

• A society/economy grows "richer" when it can produce enough resources for itself without requiring everyone to work on producing those resources. In that case, the available excess labor can produce discretionary items, like art, pop music, software, soft drinks, philosophy, etc.

• As technology advances a smaller and smaller percentage of the population is needed to produce the necessities. The rest can spend their time producing discretionary items.

• So at this point we are all well fed, and we are all willing to spend our extra money supporting our local NPR stations.

• But what happens when there is shock to the economy and people find that they have less "wealth" than they thought they had? Presumably they will spend less on discretionary items, and the people who create those items will be out of work. Where do we go from there?

So I am looking for a model to explore these kinds of issues.

I must say that I'm surprised at the number of things I had to write down to explain what I am after. I thought it would be simpler. And I want something as simple as possible.

Any thoughts/suggestions?

-- Russ

On Sun, Apr 12, 2009 at 9:14 AM, Victoria Hughes <[hidden email]> wrote:

> Attention and action = the price to consume.

is it possible to have an idea / new information and not in some way, internally or externally, react to it?

Memes spread. Humans by design infect each other on all levels.

The Complex seems like a great example: by definition intends to do this.

Idea / attention / action-reaction / experience / new idea.

And so forth.

Am enjoying the bouncing of ideas and information in this particular string...

Tory

On Apr 12, 2009, at 7:04 AM, Jochen Fromm wrote:

The central property which emerges in markets is

the price. The central law which rules markets is

the law of supply and demand. A basic agent-based

model for markets should explain how both, the

price and the law of supply and demand, emerge

in competitive markets. It should be simple to

extend such a model to explain bubbles and crashes.

As far as I know, there is no basic model of

markets in general, there are only agent based models

of specific markets, for example stock markets,

financial markets and electricity markets. Perhaps

the law of supply and demand is too simple to justify

such a model?

Epstein and Axtell's Sugarscape is a model where

agents begin to accumulate "wealth" in some form,

but it is more about evolution of societies and less

about market mechanisms and economies.

It would be interesting to apply a basic agent-based

market model to the society of mind. If we consider the

crowd within and the battle of ideas which is going on

inside our minds, can we create an agent-based model

to explain the 'market of information' ? We have a

demand for new or highly emotional stuff, are constantly

supplied with information from the outside, and the price

we have to pay to consume it is attention.

-J.

----- Original Message ----- From: Russ Abbott

To: The Friday Morning Applied Complexity Coffee Group

Sent: Sunday, April 12, 2009 9:00 AM

Subject: [FRIAM] Agent-based market models

Does anyone know of good examples of generic agent-based market economies? I'm thinking of something as simple as this.

A population consists of agents each of which has certain continuing needs (such as food, clothing, shelter, Internet access, etc.) to survive. As a starting point, let's assume that each agent needs one unit of each of N resources every time period.  Let's also assume that each agent is specialized and is capable of creating enough of one of the needed resources to satisfy the needs of N agents. (The fact that I used the same N in both places was intentional.) To keep it simple let's assume that these acts of creation occur from scratch, i.e., that the creator doesn't need raw materials, that all that's necessary for an agent to create a needed resource is that the agent be alive. The agents presumably develop a barter economy, trading the resources they create for the resources they need to stay alive. Perhaps markets develop, and perhaps money develops. At this point the economy should be fairly stable. Each agent creates enough stuff so that s/he can trade it for what s/he needs to stay live.

Perhaps some of the agents learn how to be more efficient in creating their resource and begin to accumulate "wealth" in some form.  Perhaps the agents have discretionary desires, which they fill if they have enough resources left over after meeting their basic needs. Perhaps there are communal services that are paid for by taxes or memberships.  This could become increasingly elaborate.

It seems to me that models of this sort must have been developed -- perhaps many times. Does anyone know of any references to this sort of work?

Thanks.

-- Russ Abbott

_____________________________________________

Professor, Computer Science

California State University, Los Angeles

o Check out my blog at http://bluecatblog.wordpress.com/

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Meets Fridays 9a-11:30 at cafe at St. John's College

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Meets Fridays 9a-11:30 at cafe at St. John's College
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Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

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Meets Fridays 9a-11:30 at cafe at St. John's College
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FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

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Meets Fridays 9a-11:30 at cafe at St. John's College
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Meets Fridays 9a-11:30 at cafe at St. John's College
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Meets Fridays 9a-11:30 at cafe at St. John's College
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[Robert Holmes]

If you'd like to get a sense of how the economy works, see if you can get your hands on a MONIAC (or more likely a software emulation of one) - see http://en.wikipedia.org/wiki/MONIAC_Computer . It's a water powered analogue computer that was built in 1949 to get an understanding of money flows in a national economy.

However you should also check Terry Pratchett's Discworld novel "Making Money" in which it was discovered that as these analogue computers get increasingly accurate they start to directly effect the reality that they are modeling. Horrible and perilous feedback loops result...

Robert

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[Ted Carmichael]

I'll have to read that paper soon ... but if there's something in the first paragraph that is blatantly wrong, it's so hard to keep reading.

I think the problem with Marx is he keeps confusing continuous phenomena with binary ones.  Take this sentence: "If they [the working class] could produce their own means of subsistence, they would not be compelled to sell their labor-power to capitalists."  They could - and did - produce their own subsistence back in the day.  But then someone figured out it's not much harder to make two loafs of bread than it is to make one.  So he had one to eat, and one to trade.

Then, since this guy had all this extra bread, another guy figured he could concentrate on fishing all day, then trade some fish for some bread.  Both of them were more efficient, so they had extra food to have some kids.  Or take a nap.  Whichever.

These working class folks don't sell their "labor-power" to capitalists because they are forced to.  They do it because it's more efficient to make money and buy lots of different things than it is to become proficient at making - or growing, or catching - lots of different things for themselves.

Money emerges because it also makes us more efficient.  We can "store" excess production to be used whenever we want; therefore, there is less waste associated with being more productive.  If we save up enough of this excess, we can then trade it for labor and material to build capital-intensive efficiencies ... thereby producing even more excess.  Eventually, the "things we need" become much cheaper relative to the "things we want."

Anyway, it may be true that a "land tax" could force a society to create money.  But money will spring up all on it's own, simply because it's more efficient.  Money is just a way to store excess production.  Any durable good will do the same thing.  But the magic of money is that it is not, inherently, worth anything ... except by mutual agreement of everyone.

Oh, sure ... money used to be worth something.  The earliest banks were a place for the wealthy (or anyone will excess stored production) to keep their stuff safe.  Not just gold - anything.  Tools, rugs, furniture, gems - whatever.  The "bankers" assigned a value in some common, durable resource - such as gold or silver, or coins of the realm - and that was how much "equity" the rich folks had.  Then someone with credit in a bank could write a note saying, "Please pay (insert name here) ten gold coins upon receipt of this note," in order to buy a horse.  The guy who just sold the horse can then take that "check" to the proper bank at his leisure and get his coins.  

OR ... he could trade that check for a keg of beer and a pig.  But it's easier (more efficient) to buy beer and pigs from two different people.  And it's safer to keep the coins in the bank until their needed.  So banking spread, slowly, down to the masses.  And eventually we figured out that we don't really need the gold to back up the money, and therefore we freed our wealth from the constraint of material goods completely.  Then we all got rich.

I guess you could call it "trust."  But we really just developed better and better ways to verify if the check, or bank note, was "good."  We developed systems - account numbers, signatures, identification - that work well enough so that fraud is minimized.  Soon the system was so robust that money - worthless, wonderful money - became nothing more than an idea that everyone agreed on.

Anyway, I guess I have the same problem as Russ, writing more than I meant to.  But I agree - Pratchett is a great source for this sort of thing.  So is Neal Stephenson.  But Pratchett is funnier.

Cheers,

Ted

On Sun, Apr 12, 2009 at 11:48 PM, Tom Carter <[hidden email]> wrote:

Russ -

  Thanks . . .

  As far as thinking about how economies "really" work . . . what follows is not really a response to your questions, but a source for thinking about transitions from subsistence/barter to a "monetized" system . . .

  A clever scheme:

    1.)  Find a region where there is a subsistence/barter "economy" (with, typically, tribal/communal shared land).

    2.)  With "high minded" fanfare, institute "land reform."  That is, divide the land up into small plots, and assign "ownership" of the plots to individuals.

    3.)  Now, the clever part:  establish a "land tax," but make sure that the "land tax" must be paid in currency.  Note that an "income tax" won't work, because then people could remain in their subsistence/barter mode, avoid having any accountable "income," and thus avoid the "taxation" trap . . .

    4.)  Before long, everyone will have to either switch to "cash crops," or engage in "wage labor" (or, more likely, both) in order to get currency to pay the "land tax."

    5.)  You will then have a "monetized" economy, together with a ready pool of "wage laborers," and "consumers" who purchase goods, since they have moved to "cash crops," away from subsistence farming.

  A quick Google search yields this essay (the Google search was:  colonial land taxation cash crop):

    http://www.cfeps.org/pubs/wp-pdf/WP25-Forstater.pdf

  A quote from the essay:  "The history of direct taxation in colonial capitalism also has some wider

theoretical implications. It shows, for example, “that ‘monetization’ did not spring forth

from barter; nor did it require ‘trust’—as most stories about the origins of money claim”

15 (Wray, 1998, p. 61). In the colonial capitalist context, money was clearly a “creature of

the state” "

  Anyway . . .

tom

On Apr 12, 2009, at 5:07 PM, Russ Abbott wrote:

Hey Tom,

Very nice work. Do you have anything that would help build intuition about how it all works? 

Also, what I'm after is an understanding of how an economy works. Your model says that an economy that satisfies certain conditions will (inevitably) wind up with a certain wealth distribution. But it doesn't tell me what's happening in the economy -- only that some people will become rich and a lot more will become poor. I'd like to develop a feeling for what's actually going on in the economy. 

For example, in my original model in which (a) each agent needs to consume one unit of each of N different resources at each time step (b) there are N agents each of which produces N units of a particular resource i (different from each agent) and (c) agents trade (barter style) units of resource one for one as needed, it seems to me that there will be no wealth accumulation. Everything that is produced is consumed, and as long as agents are able to trade with each other on a one-for-one basis, every agent survives but no agent accumulates any excess.  So that doesn't quite fit the model.

Furthermore, what happens if some agents (as a result of technological advances) are able to produce N units of a resource in less than one time step? Then those agents will have time on their hands and can produce something other than the resource that they contribute to the community. So they start producing resources that no one needs -- but that perhaps some agents want.

The agents with time on their hands then exchange these discretionary resources among each other. Again this might be modeled as a barter system -- although some convenient resource could come to serve as a unit of measure and medium of exchange. If you take this to the limit so that every agent is producing nothing but discretionary resources (i.e., the "needs" are so cheap to produce that there is no point keeping track of them), then what? In this model, every agent creates N units of value every time step. So there will never be any agents with no resources. 

In addition, since every transaction involves the exchange of units of resource of the same value, it seems like there is no room for accumulation of wealth. (This is assuming that one acquires a resource in order to consume, i.e., destroy, it.) So when two agents exchange resources, they are both left poorer since they each consume the received resource. In this model an agent grows wealthy only by not exchanging resources and keeping all the resources it produces. It then has the ability eventually to go on a shopping spree, pig out, and consume lots and lots of resources at one time.  But what else is that wealth good for in this economy?

So all this doesn't quite seem to fit the model you are describing.

-- Russ

On Sun, Apr 12, 2009 at 4:31 PM, Tom Carter <[hidden email]> wrote:

All -

  The real "random walks" link:

  http://csustan.csustan.edu/~tom/SFI-CSSS/2009/LectureNotes/Random%20Walk/

tom

On Apr 12, 2009, at 3:58 PM, Tom Carter wrote:

All -

  Apropos some of this, there are notes from lectures I've given recently on some of these topics here:

  Math Club lecture  (including some discussion of the "wealth model," and some "power laws" discussion)

  Black-Scholes/High Finance

  Random Walks

tom

On Apr 12, 2009, at 11:16 AM, Stephen Guerin wrote:

Russ writes:

there are N agents; N resources are needed for survival. So if the aggregate production is evenly distributed everyone has a subsistence living.

I don't think this is necessarily true.

Your mentioning a gift economy is further a reason to look at a model as simple as the Tom Carter/Victor Yakovenko model I mentioned where agents are giving a dollar to another random agent (ie gifting). This model, with minimal assumptions, generates non-equitable distribution of wealth where very few agents end up holding most of the wealth (Boltzmann distribution) even though the average wealth in the model is unchanged at $50/agent.

The important constraint in the model is that agents can only have positive amounts of cash/goods -- they can't gift a dollar they don't have.

Just as energy distributes itself as a boltzmann distribution as particles can not have less than zero energy after a collision (transaction). Basically we have diffusion against a wall in both models. Of course we can introduce debt and progressive taxes to the economic model to mess with the dynamics, but I think it's important to recognize the non-equity is there from the beginning with very minimal assumptions. Note that the wealthy agents do turnover in this model so the definition of what is equitable is important.

-Steve



On Apr 12, 2009, at 11:40 AM, Russ Abbott wrote:

Thanks for all the responses.  What prompted my question was thinking about the "end state" of the current financial crisis.  The question is: what does a successful stable economy look like? Only secondarily was I asking about markets, wealth distribution across society, etc., which is what many of the existing models focus on.

In attempting to describe the foundations of a stable economy I was making the following assumptions.

• We live off the gift of free energy -- the sun. So in some sense a stable economy requires little more than harvesting that energy.

• As human beings we have the innate (i.e., also free) ability to transform that energy into other forms that we need. For example, most of us on this list are capable of writing code. I'm taking skills like that as more free gifts from nature. Yes, it requires, education, study, practice, etc., but ultimately it grows out of our being alive, a free gift.

• In talking about "free gifts" from nature, I'm not trying to be spiritual, new age-y, etc. It just seems to me to be the way the world works. So I'm willing to build it into the model.

• But, even though we live off these free gifts, we all need energy to survive. If you look at my "Reductionist blind spot" paper, you see that we are what I call dynamic entities. Dynamic entities need to import externally supplied energy to persist -- in our case food, at least. So even though we find ourselves in a world in which there is externally supplied energy available to be imported (from the sun and its stored versions), we are each still required to do something to import it for ourselves. That is, we must each work for a living.

• Presumably a standard economic model says that we live at a subsistence level if the amount of work we do matches our needs. If I spend all my working hours doing nothing more than earning what I need to survive, that's subsistence.

• I want to allow specialization so I suggested that each agent specializes in producing some resource but that the aggregate amount produced exactly satisfies the needs of the producers. That is, each agent produces N units of his specialty resource; there are N agents; N resources are needed for survival. So if the aggregate production is evenly distributed everyone has a subsistence living.

• A society/economy grows "richer" when it can produce enough resources for itself without requiring everyone to work on producing those resources. In that case, the available excess labor can produce discretionary items, like art, pop music, software, soft drinks, philosophy, etc.

• As technology advances a smaller and smaller percentage of the population is needed to produce the necessities. The rest can spend their time producing discretionary items.

• So at this point we are all well fed, and we are all willing to spend our extra money supporting our local NPR stations.

• But what happens when there is shock to the economy and people find that they have less "wealth" than they thought they had? Presumably they will spend less on discretionary items, and the people who create those items will be out of work. Where do we go from there?

So I am looking for a model to explore these kinds of issues.

I must say that I'm surprised at the number of things I had to write down to explain what I am after. I thought it would be simpler. And I want something as simple as possible.

Any thoughts/suggestions?

-- Russ

On Sun, Apr 12, 2009 at 9:14 AM, Victoria Hughes <[hidden email]> wrote:

> Attention and action = the price to consume.

is it possible to have an idea / new information and not in some way, internally or externally, react to it?

Memes spread. Humans by design infect each other on all levels.

The Complex seems like a great example: by definition intends to do this.

Idea / attention / action-reaction / experience / new idea.

And so forth.

Am enjoying the bouncing of ideas and information in this particular string...

Tory

On Apr 12, 2009, at 7:04 AM, Jochen Fromm wrote:

The central property which emerges in markets is

the price. The central law which rules markets is

the law of supply and demand. A basic agent-based

model for markets should explain how both, the

price and the law of supply and demand, emerge

in competitive markets. It should be simple to

extend such a model to explain bubbles and crashes.

As far as I know, there is no basic model of

markets in general, there are only agent based models

of specific markets, for example stock markets,

financial markets and electricity markets. Perhaps

the law of supply and demand is too simple to justify

such a model?

Epstein and Axtell's Sugarscape is a model where

agents begin to accumulate "wealth" in some form,

but it is more about evolution of societies and less

about market mechanisms and economies.

It would be interesting to apply a basic agent-based

market model to the society of mind. If we consider the

crowd within and the battle of ideas which is going on

inside our minds, can we create an agent-based model

to explain the 'market of information' ? We have a

demand for new or highly emotional stuff, are constantly

supplied with information from the outside, and the price

we have to pay to consume it is attention.

-J.

----- Original Message ----- From: Russ Abbott

To: The Friday Morning Applied Complexity Coffee Group

Sent: Sunday, April 12, 2009 9:00 AM

Subject: [FRIAM] Agent-based market models

Does anyone know of good examples of generic agent-based market economies? I'm thinking of something as simple as this.

A population consists of agents each of which has certain continuing needs (such as food, clothing, shelter, Internet access, etc.) to survive. As a starting point, let's assume that each agent needs one unit of each of N resources every time period.  Let's also assume that each agent is specialized and is capable of creating enough of one of the needed resources to satisfy the needs of N agents. (The fact that I used the same N in both places was intentional.) To keep it simple let's assume that these acts of creation occur from scratch, i.e., that the creator doesn't need raw materials, that all that's necessary for an agent to create a needed resource is that the agent be alive. The agents presumably develop a barter economy, trading the resources they create for the resources they need to stay alive. Perhaps markets develop, and perhaps money develops. At this point the economy should be fairly stable. Each agent creates enough stuff so that s/he can trade it for what s/he needs to stay live.

Perhaps some of the agents learn how to be more efficient in creating their resource and begin to accumulate "wealth" in some form.  Perhaps the agents have discretionary desires, which they fill if they have enough resources left over after meeting their basic needs. Perhaps there are communal services that are paid for by taxes or memberships.  This could become increasingly elaborate.

It seems to me that models of this sort must have been developed -- perhaps many times. Does anyone know of any references to this sort of work?

Thanks.

-- Russ Abbott

_____________________________________________

Professor, Computer Science

California State University, Los Angeles

o Check out my blog at http://bluecatblog.wordpress.com/

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FRIAM Applied Complexity Group listserv

Meets Fridays 9a-11:30 at cafe at St. John's College

lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================

FRIAM Applied Complexity Group listserv

Meets Fridays 9a-11:30 at cafe at St. John's College

lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

[Jochen Fromm-4]

I found this link on markets today: it says it is precisely the less complex
systems that can be planned and the more complex systems that must develop
spontaneously. Quite paradox.
http://www.libertarianism.org/ex-9.html

It says nothing about the invisible hand from Adam Smith, though. Do you
think we have an agent-based model which explains the self-regulating nature
of markets ?

-J.


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[Robert Howard-2-3]

Perhaps complexity is not in the quantity of the agents, but the quantity of
the rules each agent must obey.

So what are the requirements and rules of a free market?
My guess of an incomplete set are:
OBSERVATIONS:
The grass is greener on the other side. If I have an orange tree and you
have an apple tree, at some point I'm going to value your apples more than
my oranges, and you will value my oranges more than your apples.
REQUIREMENTS:
Ownership = Control = the right to trade it. Property rights and its legal
registration must exist. The agents must know who owns what. If two agents
own the same thing, some system must exist to resolve conflicts.
RULES:
1) Right to refuse. One person can propose a trade and another person can
refuse or counter propose. If no trade occurs, neither is worse off. If a
trade does happen, by definition both parties must be happier. No third
party observer is allowed to have an opinion.
2) Trade is honest. If a swap was made under false pretense or any form of
coercion then no trade occurred. The swap must be undone.

Compare these rules to air traffic management.

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf
Of Jochen Fromm
Sent: Thursday, April 16, 2009 12:53 PM
To: The Friday Morning Applied Complexity Coffee Group
Subject: Re: [FRIAM] Agent-based market models

I found this link on markets today: it says it is precisely the less complex

systems that can be planned and the more complex systems that must develop
spontaneously. Quite paradox.
http://www.libertarianism.org/ex-9.html

It says nothing about the invisible hand from Adam Smith, though. Do you
think we have an agent-based model which explains the self-regulating nature

of markets ?

-J.


============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org


============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

[Nick Thompson]

What do we need with abm's when we have all those good EQUATIONS.
 
Nick
 
Nicholas S. Thompson
Emeritus Professor of Psychology and Ethology,
Clark University ([hidden email])
http://home.earthlink.net/~nickthompson/naturaldesigns/
 



> [Original Message]
> From: Jochen Fromm <[hidden email]>
> To: The Friday Morning Applied Complexity Coffee Group <[hidden email]>
> Date: 4/16/2009 6:09:17 PM
> Subject: Re: [FRIAM] Agent-based market models
>
> I found this link on markets today: it says it is precisely the less
complex
> systems that can be planned and the more complex systems that must
develop
> spontaneously. Quite paradox.
> http://www.libertarianism.org/ex-9.html
>
> It says nothing about the invisible hand from Adam Smith, though. Do you
> think we have an agent-based model which explains the self-regulating
nature
> of markets ?
>
> -J.
>
>
> ============================================================
> FRIAM Applied Complexity Group listserv
> Meets Fridays 9a-11:30 at cafe at St. John's College
> lectures, archives, unsubscribe, maps at http://www.friam.org



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FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
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