quarta-feira, dezembro 28, 2011

Simplesmente delicioso

"In the year 2000, the investment magazine Capital announced a stock-picking contest. More than 10,000 participants, including the editor-in-chief, submitted portfolios. The editor laid down the rules: he chose fifty international Internet equities and set out a period of six weeks in which everyone could buy, hold, or sell any of these stocks in order to make profit. Many tried to gain as much information and insider knowledge about the stocks as possible, while others used high-speed computers to pick the right portfolio. But one portfolio stood out from all others.
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This portfolio was based on collective ignorance rather than on expert knowledge and fancy software, and it was submitted by economist Andreas Ortmann and myself. We had looked for semi-ignorant people who knew so little about stocks that they had not even heard of many of them. We asked a hundred pedestrians in Berlin, fifty men and fifty women, which of the fifty stocks they recognized. Taking the ten stocks whose names were most often recognized, we created a portfolio. We submitted it to the contest in a buy-and-hold pattern; that is, we did not change the composition of the portfolio once it was purchased.
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We hit a down market, which was not good news. Nevertheless, our portfolio based on collective recognition gained 2.5 percent. The benchmark proposed by Capital was its editor-in-chief, who knew more than all the hundred pedestrians together. His portfolio lost 18.5 percent. The recognition portfolio also had higher gains than 88 percent of all portfolios submitted, and beat various Capital indices. As a control, we had submitted a low-recognition portfolio with the ten stocks least recognized by the pedestrians, and it performed almost as badly as the editor-in-chief ’s. Results were similar in a second study, where we also analyzed gender differences. Interestingly, women recognized fewer stocks, yet the portfolio based on their recognition made more money than those based on men’s recognition. This finding is consistent with earlier studies suggesting that women are less confident about their financial savvy, yet intuitively perform better."
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Trecho retirado de "Gut feelings : the intelligence of the unconscious" de Gerd Gigerenzer.

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