Archive for the 'Rational Expectations Theory' Category

Oct 27 2009

Homo Economicus – “Economic Man”: Guest Lesson for ZIS Theory of Knowledge classes

Homo Economicus, the “Economic Man” is the concept underlying most economic theories. It holds that all humans are purely self-interested, rational actors who have the ability to make judgments that fulfill their subjectively defined ends. In modern economic theory, the end man seeks is generally accepted to be increasing monetary well-being and material wealth.

Philosophical foundations of “homo economicus“:

Aristotle (350 BC):

Again, how immeasurably greater is the pleasure, when a man feels a thing to be his own; for surely the love of self is a feeling implanted by nature and not given in vain, although selfishness is rightly censured; this, however, is not the mere love of self, but the love of self in excess, like the miser’s love of money; for all, or almost all, men love money and other such objects in a measure. And further, there is the greatest pleasure in doing a kindness or service to friends or guests or companions, which can only be rendered when a man has private property. These advantages are lost by excessive unification of the state.

  • What does Aristotle think about the interference of government in the private property rights of man?

Adam Smith (1776):

In almost every other race of animals, each individual, when it is grown up to maturity, is entirely independent, and in its natural state has occasion for the assistance of no other living creature. But man has almost constant occasion for the help of his brethren, and it is in vain for him to expect it from their benevolence only. He will be more likely to prevail if he can interest their self-love of them. Whoever offers to another a bargain of any kind, proposes to do this. Give me that which I want, and you shall have this which you want, is the meaning of every such offer: and it is in this manner that we obtain from one another the far greater part of those good offices which we stand in need of. It is not from the benevolence of the butcher the brewer or the baker that we expect our dinner, but from their regard to their own interest. We address ourselves, not to their humanity, but to their self-love, and never talk to them of our own necessities, but of their advantages.

  • How does Smith believe the pursuit of individual self-interest can lead to benefits for society as a whole?

John Stuart Mill (1836)

What is now commonly understood by the term “economics” is not the science of speculative politics, but a branch of that science. It does not treat of the whole of man’s nature as modified by the social state, nor of the whole conduct of man in society. It is concerned with him solely as a being who desires to possess wealth, and who is capable of judging of the comparative efficacy of means for obtaining that end. It predicts only such of the phenomena of the social state as take place in consequence of the pursuit of wealth. It makes entire abstraction of every other human passion or motive; except those which may be regarded as perpetually antagonizing principles to the desire of wealth, namely, aversion to labor, and desire of the present enjoyment of costly indulgences. These it takes, to a certain extent, into its calculations, because these do not merely, like our other desires, occasionally conflict with the pursuit of wealth, but accompany it always as a drag, or impediment, and are therefore inseparably mixed up in the consideration of it.

  • According to Mill, labor is not something humans value for its own sake, but only because it allows us to do what?

Fredrick von Hayek (1930s):

We will benefit our fellow man most if we are guided solely by the striving for gain. For this purpose we have to return to an automatic system which brings this about, a self-directing automatic system which alone can restore liberty and prosperity.

  • How would Hayek respond to those who argue that the government’s role in society and the economy is to promote fairness and equality?

Are you a “homo economicus“? – The Golden Balls Game

The prize: $1 million

How to play:

  • Find an opponent from among your classmates.
  • You and your opponent have never met before today, never spoken to one another, and will never see nor speak to one another again after the game ends.
  • Since you do not know or care about your opponent, you must play this game with your own self-interest in mind, and assume that your opponent will play it with his or her self-interest in mind.
  • You have in front of you two folded pieces of paper. One says “SPLIT” and one says “STEAL”
  • You must decide which piece of paper to select, based on the following possible outcomes

The payoffs:

  • If both players decide to “split”, each player will take home $500,000.
  • If one player chooses to “split” and the other chooses to “steal” then the one who chooses to steel will take home $1 million, and the one who chose to split will get nothing
  • If both players choose to “steel”, both players go home empty handed.

Split

Steal

Split

Player 1: $500,000

Player 2: $500,000

Player 1: $1 million

Player 2: 0

Steal

Player 1: $0

Player 2: $1 million

Player 1: $0

Player 2: $0

Let’s play!

  • You only have one chance to play this game. Remember, you care only about yourself and should do what is best for you.
  • On the teacher’s command, reveal your decision to your opponent.
  • Take note of your payoff and report it to the teacher

Discussion:

  • What was the outcome of your game?
  • Was the outcome rational? Was it predictable?
  • Did the outcome reflect the concept of “homo economicus“? Were you and your opponents’ decisions purely self-interested and coldly rational, intended to maximize your OWN payoff?
  • Are you a homo economicus? What would homo economicus have done? Why?

Videos:

Golden Balls – the real gameshow: http://www.youtube.com/watch?v=p3Uos2fzIJ0&feature=player_embedded

[youtube]http://www.youtube.com/watch?v=p3Uos2fzIJ0&feature=player_embedded[/youtube]

  • Which player was more like homo economicus? Sarah or Steve?
  • Which player acts rationally? What makes it rational?
  • Which player acts irrationally? What makes it irrational?

“The Trap”: Intro to game theory and rational self-interest in politics and economics: http://www.youtube.com/watch?v=qzNcY-gZdiA&feature=related

[youtube]http://www.youtube.com/watch?v=qzNcY-gZdiA[/youtube]

  • John Nash’s Game Theory proved that “a system driven by selfishness did not have to lead to chaos”, that “there could always be a point of equilibrium in which everyone’s self-interest is perfectly balanced against each other”? How does such a theory support the concept of homo economicus?
  • What is the Prisoner’s Dilemma? “The rational choice is always to betray the other person.” What does this say about humans in society? Is government regulation needed to prevent constant betrayal by greedy, self-interested individuals? Or are constant betrayal and self-interest themselves capable of achieving a socially optimal outcome?

Noam Chomsky on the inefficiency of markets and the threat posed by de-regulation: http://www.youtube.com/watch?v=QPl27BO7fHE&feature=related

[youtube]http://www.youtube.com/watch?v=QPl27BO7fHE[/youtube]

  • What is the “externality” of financial market failure that Chomsky identifies?
  • Why is the failure of a financial market more worrisome than the failure of a market like that for used automobiles?
  • How does Chomsky feel about the de-regulation of financial markets? Does he think markets are always rational and efficient?

Modern applications of the concept of Homo Economicus:

  • Rational Expectations Theory (RET): This economic theory assumes that humans acting generally in their own self-interest will make rational decision based on the best available information. Therefore, it assumes that people (and therefore, markets, which are made up of rational people) do not make systematic errors when predicting the future.
  • Efficient Markets Hypothesis (EMH): Rooted in Rational Expectations Theory, which itself is rooted in the concept of homo economicus, EMH says that prices in markets, particularly financial markets (whose collapse has caused the today’s global economic crisis) represent the best possible estimates of the risks attached to the ownership of various financial assets (stocks, shares, bonds, etc…) Asset bubbles are therefore impossible, since “bubble” implies an irrational and unsustainable increase in the value of an asset which will ultimately “burst”. Markets are “self-correcting”, and the most effective tool for assuring economic stability is free markets, rather than government regulation or oversight.

Connecting the dots – from Homo Economicus to today’s Economic downturn:


The general acceptance of theories rooted in the concept of homo economicus led to the de-regulation of financial markets, which allowed money and resources to go whichever way the “market” (rational or not) determined.

  • During the last decade, the market decided that more and more money and resources should go towards particular assets, specifically the United States mortgage market (the market for new homes in the US).
  • As money flooded the US home mortgage market, it became cheaper and easier for Americans to get loans to build a home. GREAT, RIGHT?! Well, only until it came time to pay back those loans.
  • Trillions of dollars worldwide became tangled up in the US mortgage market, representing households’ savings from around the globe.
  • When Americans suddenly found their loans coming due, they found it hard to repay them due to adjustable interest rates and falling home price (supply had grown more rapidly than demand).
  • American and many Europeans began defaulting on their mortgages, meaning all that money that had been lent to home buyers literally disappeared.
  • Banks and financial markets faced a “liquidity crisis”, meaning they had no money.
  • Lending stopped to households, firms, and other banks , meaning spending on goods and services decreased, meaning jobs were lost and economies entered recession.
  • How could any of this have happened if the concept homo economicus and the economic theories based on the concept are correct? Are humans always rational, calculating, perfectly informed, self-interested beings acting purely in their own self-interest?

Conclusion: The concept of homo economicus has formed the basis for economic theories for centuries and for major macroeconomic policies over the last 30 years. Policies of “market liberalization” (freeing the market from the guiding, regulatory hands of government) have led to great prosperity, but even greater risk and volatility as irrational exuberance over asset prices has led to inefficient market outcomes, bubbles, and financial shocks plunging the “real” economies of the world into recession.

Perhaps a more complete understanding of humans is needed as the human science of economics enters a new era. The human as a cold, rational, calculating creature interested in only his own gain is an over-simplification, and forming theories and policies on such an assumption is dangerous. The future of economics must incorporate a more complete and complex understanding of human behavior if the economic crises of the last two years are to be avoided down the road.

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Oct 23 2007

WTO – a podcast introduction, continued…

Introduction to the WTO, continued…

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Apr 16 2007

Irrational Expectations

Americans united in recession fears — Shanghai Daily | 上海日报 — English Window to China News

Here’s an interesting article with which one could launch a case study into the American psyche. It also connects to AP Economics in that it seems to support the Rational Expectations Theory that firms and households will respond to expectations of future economic conditions by altering their behavior now, thus accelerating the onset of those very conditions; a sort of self-fulfilling prophecy, if you will.

The irony of America’s current economic situation is, however, that while 60% of Americans predict a recession in the near future, these predictions seem wholly irrational when we consider the state of the economy at this very moment! Unemployment is at its lowest level in five years, 64% of Americans surveyed said their own finances were very secure, and 57% seem to think the economy is doing well. So why the fears of recession?

Interesting article, all told. The American people seem to have things as good as they’ve been in years, yet there’s this predominant fear of things turning for the worse any day. If rational expectations theory is correct, then it’s a safe bet that American’s pessimism in itself could trigger a recession, in which case we’ll all get just what we didn’t want, but somehow failed to avoid due to our irrational expectations!

I have another theory about what may have triggered American’s pessimism in the first place; it has something to do with something I call the “savior syndrome”… but I’ll save that one for another posting!

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