The Rational Market and Other Financial Myths | Big Think

The Rational Market and Other Financial Myths

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Justin Fox of Time Magazine explains the appeal and the downfall of the rational market theory and tells us the next great economic theories and investment models.

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Justin Fox:

Justin Fox is the business and economics columnist for Time magazine. He also writes the "Curious Capitalist" blog at Time.com.

Before joining Time in January 2007, Fox spent more than a decade at sister publication, Fortune. At Fortune, he covered a wide variety of topics related to economics, finance, and international business. In 2000 and 2001, he was the magazine's Europe editor, based in London.

Earlier in his career, Justin worked at several newspapers, including American Banker and the Birmingham News. He has a B.A. in international affairs from Princeton.

Fox is a Young Global Leader of the World Economic Forum. His first book, The Myth of the Rational Market, will be published by Collins in 2008.

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TRANSCRIPT:

Question: What is the appeal of the rational market theory

Justin Fox: The basis of the theory is that Wall Street knows what it’s doing: that prices move on stock markets in particular, but financial markets in general, for a good reason—because all these investors and speculators are bringing all this information and opinion to bear, and are therefore delivering the best possible assessment of what a particular stock or bond or whatever else is worth. And part of the attraction of is, at some level, it is at least partly true. Stock markets are not completely driven by noise; they are not completely driven by irrationality. If they were, I think we would have decided to get rid of them at this point. Although, I guess a lot of people make money often so you never know. But, still, there’s some element of rationality and reflection of fundamentals going on in market behavior, so that’s one reason why it’s attractive.

The other reason why it’s attractive—especially the version of it that was born or reborn in 1960’s and really became incredibly influential in 70’s and 80’s and 90’s—it just makes life so much simpler. If you just simply go from the starting point that financial market prices are right, then you can do so many great things. You can calculate the cost of capital really easily if you’re a corporate decision maker trying to decide whether you want to do an investment or not. You can pick out an investment strategy that makes sense, that balances and risk and reward more appropriately, very easily. You can basically approach the market in this scientific fashion that can be taught to other people and handed down to other people. It isn’t all about gossip or people’s strange opinion. It’s the scientific straightforward guide to decision-making in and around the market.

Question: What alternatives to the rational market theory are being put forward?

Justin Fox: One of the fascinating things that’s going on right now is a bunch of economists, Paul Krugman and Brad DeLong among them, are trying to come up with pretty much rational explanation of bubbles: how bubbles work and what the interaction is between the leverage and bubbles, and what causes them. I’m fascinated by that. I don’t know if it will deliver any real answers, but it is an attempt to use the fact that—even [when] people who, in their individual position as a hedge fund manager or whatever, are behaving entirely rationally need to maximize their own well-being—it creates this system where markets go bonkers, and I think that the lessons that will probably come out of that is: leverage is dangerous. That’s really interesting to me.

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