Another dubious survey

One of factoids Alistair McFarquhar offered up trying to support his post that vanished down the memory hole was this:

Among Economists almost twice as many believe that rising greenhouse gas levels will cause the economy to grow. Most think rising greenhouse gas levels will have virtually no impact on income per person. The vast majority (73.2%) predicts that the impact will be less than 5 percent one way or the other.

His source was this article by Robert Whaples in Tech Central Station. When newspapers report survey results they give the sample size and confidence interval, but Whaples didn't. I found the sample size in the original journal article. Guess what it was?

  1. That 73.2% number given to three significant figures was really 41/56. It should have been given as 70 +/- 15%.

Furthermore, Whaples had surveyed 210 economists, so the response rate was just 27%. The vast majority of economists did not respond to the survey, and might have different opinions from those that did respond.

I don't think that the survey is entirely useless, but it is misleading to present a result like 73.2% without revealing how very uncertain that number is.

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Who would think of asking economists that question? Economists founder when they try to predict the past, and somebody asks them about the future?

By RustyKnob (not verified) on 11 Jan 2007 #permalink

"(Here are the complete responses: a) more than 10 percent lower = 12.5%; b) about 5 to 10 percent lower = 7.1%; c) about 1 to 5 percent lower = 21.4%; d) less than 1 percent lower or higher = 35.7%; e) about 1 to 5 percent higher = 16.1%; f) more than 5 percent higher = 7.1%.)"

So 41% of the sample think that stabilising CO2 levels (a very ambitious objective far beyond, for example, what Kyoto envisions) will have a significant net economic benefit and another 35.7% think that doing so will either be slightly positive for the economy or only slightly negative.

Only 7.1% think that there will be a major economic cost to stabilising CO2 levels.

I wonder what the usual suspects who'll be flogging this survey to death in the blogosphere to support their anti-environment position think of the strong support shown in the same survey for a major increase in US energy taxes? Or the majority support for higher CAFE standards?

By Ian Gould (not verified) on 11 Jan 2007 #permalink

Only 7.1% think that there will be a major economic cost to stabilising CO2 levels.

Nitpick: did you mean benefit or am I misreading the numbers in the first para?

By anonymous (not verified) on 11 Jan 2007 #permalink

7.1% think GDP will be higher by more than 5% if CO2 levels continue to rise - i.e. they think stabilising GHG levels will cost more than 5% of GDP.

By Ian Gould (not verified) on 11 Jan 2007 #permalink

Hey, Tim, speaking of climate and stats, there's a new gunslinger in town and he's looking mean. Be sure to read the comments.

By Steve Bloom (not verified) on 11 Jan 2007 #permalink

Do Economists Agree on Everything? Judging by the response rate, they also agree that the survey was bollocks, or at least a suboptimal use of their time.

When the error on either side is 15%, I think it's time to ignore the study.

Thom:

"When the error on either side is 15%, I think it's time to ignore the study."

Really? Well, that buggers The Lancet report then.