onsdag, november 29, 2006

Økonomer og ikke-økonomer

Opfatter økonomer og ikke-økonomer verden forskelligt?

Den bedste analogi er i mine øjne fysik, der er ikke mange lægmænd der mener at have forstået de finere detaljer i kernefysik, eller sågar "The Big Bang," men der er utroligt mange lægfolk som mener sig berettiget til at udbrede sig om hvad sandheden er på det økonomiske område.

Fra en udemærket artikel (via Mankiw) der omhandler hvordan man bliver påvirket når man læser økonomi er der følgende meget sigende afsnit:
"About midway through the semester, during the unit we spend learning about how the gross domestic product is computed, he reads to the class from an article in the Chicago Tribune with the headline, “Corporate Giants Dwarf Many Nations.” The piece compares the annual sales of large corporations like Wal-Mart with that of small countries, like Israel, showing that many of the world’s 200 largest corporations are as large as entire national economies, and therefore have a great deal of political and economic clout. After quoting at length, Sanderson points out how implausible it is that 200 companies, with one third of one percent of the world’s workforce, could produce 28 percent of the world’s economic activity. “There’s a word for it,” Sanderson says. “Two words, actually. The first is ‘Horse.’ “

The problem, Sanderson notes, is that “sales” is a terrible measurement for the economic output of a company like Wal-Mart, because it only produces a very small percentage of the value of any product is sells. When you buy pistachios at Wal-Mart, it’s not like those nuts were grown on a Wal-Mart farm. Wal-Mart bought them from someone and then resold them for a profit. “If we were counting GDP, we just want to count what’s the net contribution, what’s the value added?” he explains. “Last year, worldwide Wal-Mart sold $285 billion worth of goods and services, but paid manufacturers $220.” Sanderson’s point is pretty obvious, if you think about it. And yet the article gets it wrong over and over, which nearly sends Sanderson around the bend. “This happens to be the political rhetoric: ‘These 200 corporations dominate the world.’ They don’t. They’re a very small percentage of GDP,” Sanderson says. “Those who are criticizing very large multinational corporations are doing a disservice if they don’t get the math right.”

The Economist View
har et længere indlæg om hvorfor det er lige så besværligt at forklare økonomi til en ikke-økonom, som det er at forklare evolutionen til en ID tilhænger. "For someone who hasn't had formal training in the field, anti-economics is often more persuasive than the real thing. Paul Krugman ran into this particular brick wall a few years ago, and realised that the correct response to many criticisms of economics is "You just don't understand".


Blogger larskeller said...

Meget spændende Mads.

3/12/06 23:09  

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