But first, you go do a Google search for stated preference methods and get an idea about what they are. In short, stated preference methods (i.e., contingent valuation, contingent behavior, choice experiments [sic]) are a way to estimate monetary values for environmental resources. The methods involve asking people about what they might do when confronted with a real situation that involves monetary and environmental quality (for example) tradeoffs.
Here are two reasons:
1. Revealed preference methods are better. Real AND environmental economists love revealed preferences. People reveal their values for stuff with their behavior. In the environmental context people travel, permanently change locations and make market purchases in response to environmental quality changes. The travel cost method, hedonic price method and averting behavior method are able to capture these sorts of environmental values.
The problem with this view is that the revealed preference weenies fail to provide an alternative. In yesterday's post I provided an example where revealed preference methods would be very difficult to use. In those cases environmental (and a few other) economists might resort to stated preference methods. Then, real economists will say stuff like this when discussing your paper at conferences (not joking):
I really don't like contingent valuation, I wish there was a better way to do this stuff.
And then they proceed to bash contingent valuation without an alternative.
There is more to write here, about the research process, about mitigating hypothetical bias, about real economists misguided relative love for choice experiments and happiness data. But, class beckons so I'll leave it at that.
2. [more speculative] Real economists hate the environment. Economists tend to be conservative folk and this bleeds into their political views. Conservatives tend to hate government action towards the environment (except subsidized mining!) and anything that promotes government action should be hated. Stated preference methods attach values for policy analysis to something that previously had no value. That can only lead more government action, right?
[Note that this somehow fails to explain why most environmentalists hate stated preference methods too.]