Saturday, June 5, 2010

Models versus blogs redux

I was wrong in my post accusing bloggers of arguing based on conviction instead of models. Mark Thoma clarifies that he is basing his arguments on Eggertson and Woodford's models. I also concur with him when he says the following (emphasis mine):

Using a different model is fine. I've already noted that the models I have been using have their problems, and that there can be a legitimate debate over what type of model is best. But at some point you have to commit to a specific model and use it to answer your questions, one that has hopefully been carefully specified and thoroughly investigated, and that does not change daily. Full awareness of the model's weak spots and limitations should be used to qualify the answers you give, but you cannot avoid committing to a model of some sort. The policy advice I have been advocating is based upon these models and is fully consistent with them. That doesn't mean that other models won't give different answers, but those aren't the models I am using.

Unfortunately, when economists are arguing from different models, they really are arguing from convictions that their model is the right one.

And it is also because of this disagreement on which models should be used that I agree with Kocherlakota's claim that economists do not have a playbook - or perhaps they have too many playbooks. And while I am a strong supporter of model based policy prescriptions, I am also fully aware that an over-reliance on models is one of the reasons we are in the crisis in the first place.

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