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投稿:The Behavioral Revolution-行为革命

译文。  原文我放在回帖里啦。。

大致说来,做出一个决定要经历四个步骤。第一,分析当前的情况,其次,考虑可能的行动方针,然后,计算哪个方针对你最有利,最后,付诸行动。

在过去几个世纪以来,公共政策分析家们都认为第三步是最重要的,经济模型和整个社会科学领域的前提都是假定人们会理智地考量利弊,把自己的利益最大化



但是在这次金融危机中,出乎我们的意料,这样思维方式失灵了。就像格林斯潘上周在国会作证的时候所说,市场没有按照预期的方式运行,他很“震惊”。他说,“我错误地认为,银行和其他金融机构会为了自己的利益保护它们的股东和股价。

所以,也许现在我们应该重新考虑这几个步骤的重要性。也许,现在我们应该把强调的重点从第三步转移到第一步,也就是分析。

乍一看,分析目前的情况看起来十分简单。你只需要看看,了解一下周围的情况。但是,往往看起来最简单的活动实际上是最难的,因为许多事情的发生是人们察觉不到的。观看,分析这个世界是一个活跃的过程,它赋予这个世界以意义,也使得后来的决定受到影响,具有倾向性。

经济学家和心理学家例如Amos Tversky,Daniel Kahneman,在过去的四十年里一直在研究我们观念的倾向性,做同样工作的还有Richard Thaler, Robert Shiller, John Bargh 和Dan Ariely.

我的观点是这次金融危机会开始使行为经济学家走上舞台,他们把复杂的心理学摆到公共政策领域。至少,这些人对这个问题——为什么那么多人错误地估计了他们的冒险行为——给出了似乎合理的解释。

Nassim Nicholas Taleb深受这股研究潮流的影响,Taleb不仅解释了眼前正在发生什么,而且也说明了将要发生什么。他的畅销书《无心的愚蠢》和《黑天鹅》抨击了在金融和其他领域的风险管理模型。

在《黑天鹅》,他写到,“我认为由政府支持的房丽美现在正处于一个危险的境地,就像坐在一个**桶上,有一点风吹草动就会**。”关于全球化,他写到,“全球化把各国的不稳定因素都连到了一起。”他警告说,虽然银行业的增长显示了稳定,但实际上,它增长了系统性崩溃的风险——一个银行倒闭,所有银行会跟着倒闭。“

Taleb认为,我们的大脑的进化使得我们只能适应一个比我们所面临的更简单的世界。虽然他的观点都是个人化的,但是他却是揭示了一些扭曲我们思想的观念偏见的核心:我们总是倾向于相信那些为我们的偏见通过证据的数据,而不愿相信那些违背我们意愿的数据;我们总是倾向于预期前景的时候,夸大当前的情况;我们总是倾向于把同时发生的一些事件编成一个故事;我们总是倾向于为自己应该有的能力喝彩,而实际上我们只是运气好而已。

看看这次金融危机,很容易就看到很多错误地分析。交易员们错误地估计了小概率事件的可能性。他们都被这场蔓延的危机围困,重新加强互相的风险评估。他们没有看到国家之间的联系都十分紧密,能把一个小事件变成一场大灾难。

Taleb 诅咒定量分析的风险模型,这个模型试图把一些不能模式化的东西变成模型。他相信他所谓的“人类的悲剧性的命运”,就是“在我们的思维和行动中存在内在的限制和失误,我们的承认,这是一切个人和团体行动的基础。”用这次危机来说明这个观点再好不过了

如果你开始考虑我们的错误分析,你首先会意识到的是市场并不是完美高效的,人们也不总是守卫着自己的利益,在有限的情况下,政府也会做出有倾向性的决定。但是然后你会发现,比之商人,政府官员分析局势的能力更差。他们的信息反馈机制更加不完备,而且是被政治化的,他们更加会屏蔽对自己不利的信息。

这次危机不仅是一个金融事件,而且是一个文化事件。它是一个巨大的警钟,提醒我们人类的头脑总是使人们接受一些假象,通过很大的努力,才能使人们不接受它们。

The Behavioral Revolution

The Behavioral Revolution
Roughly spea**, there are four steps to every decision. First, you perceive a situation. Then you think of possible courses of action. Then you calculate which course is in your best interest. Then you take the action.

Over the past few centuries, public policy analysts have assumed that step three is the most important. Economic models and entire social science disciplines are premised on the assumption that people are mostly engaged in rationally calculating and maximizing their self-interest.

But during this financial crisis, that way of thin** has failed spectacularly. As Alan Greenspan noted in his Congressional testimony last week, he was “shocked” that markets did not work as anticipated. “I made a mistake in presuming that the self-interests of organizations, specifically banks and others, were such as that they were best capable of protecting their own shareholders and their equity in the firms.”

So perhaps this will be the moment when we alter our view of decision-ma**. Perhaps this will be the moment when we shift our focus from step three, rational calculation, to step one, perception.

Perceiving a situation seems, at first glimpse, like a remarkably ** operation. You just look and see what’s around. But the operation that seems most ** is actually the most complex, it’s just that most of the action takes place below the level of awareness. Loo** at and perceiving the world is an active process of meaning-ma** that shapes and biases the rest of the decision-ma** chain.

Economists and psychologists have been exploring our perceptual biases for four decades now, with the work of Amos Tversky and Daniel Kahneman, and also with work by people like Richard Thaler, Robert Shiller, John Bargh and Dan Ariely.

My sense is that this financial crisis is going to amount to a coming-out party for behavioral economists and others who are bringing sophisticated psychology to the realm of public policy. At least these folks have plausible explanations for why so many people could have been so gigantically wrong about the risks they were ta**.

Nassim Nicholas Taleb has been deeply influenced by this stream of research. Taleb not only has an explanation for what’s happening, he saw it coming. His popular books “Fooled by Randomness” and “The Back Swan” were broadsides at the risk-management models used in the financial world and beyond.

In “The Black Swan,” Taleb wrote, “The government-sponsored institution Fannie Mae, when I look at its risks, seems to be sitting on a barrel of dynamite, vulnerable to the slightest hiccup.” Globalization, he noted, “creates interloc** fragility.” He warned that while the growth of giant banks gives the appearance of stability, in reality, it raises the risk of a systemic collapse — “when one fails, they all fail.”

Taleb believes that our brains evolved to suit a world much **r than the one we now face. His writing is idiosyncratic, but he does touch on many of the perceptual biases that distort our thin**: our tendency to see data that confirm our prejudices more vividly than data that contradict them; our tendency to overvalue recent events when anticipating future possibilities; our tendency to spin concurring facts into a single causal narrative; our tendency to applaud our own supposed skill in circumstances when we’ve actually benefited from dumb luck.

And loo** at the financial crisis, it is easy to see dozens of errors of perception. Traders misperceived the possibility of rare events. They got caught in social contagions and reinforced each other’s risk assessments. They failed to perceive how tightly linked global networks can transform small events into big disasters.

Taleb is characteristically vituperative about the quantitative risk models, which try to model something that defies modelization. He subscribes to what he calls the tragic vision of humankind, which “believes in the existence of inherent limitations and flaws in the way we think and act and requires an acknowledgement of this fact as a basis for any individual and collective action.” If recent events don’t underline this worldview, nothing will.

If you start thin** about our faulty perceptions, the first thing you realize is that markets are not perfectly efficient, people are not always good guardians of their own self-interest and there might be limited circumstances when government could usefully slant the decision-ma** architecture (see “Nudge” by Thaler and Cass Sunstein for proposals). But the second thing you realize is that government officials are probably going to be even worse perceivers of reality than private business types. Their information feedback mechanism is more limited, and, being deeply politicized, they’re even more likely to filter inconvenient facts.

This meltdown is not just a financial event, but also a cultural one. It’s a big, whopping reminder that the human mind is continually trying to perceive things that aren’t true, and not perceiving them takes enormous effort.
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