Monday, March 24, 2014

Economia Comportamental (I)

A grand unified theory of behavioral economics?, por Noah Smith:

Suppose that there are a whole ton of different behavioral biases, and that these vary across time, across people, and across situations so much that even with a billion lab experiments we couldn't find them all. Only once in a while will the forces be aligned to make one behavioral bias dominate; most of the time, the net effect of all the biases will be unpredictable by the outside observer. When you have an unpredictable mishmash like that, you have to model it as a stochastic process. In other words, if it's too complicated to explain deterministically, then you treat it as randomness.

So what if psychology usually just ends up injecting randomness into our decisions? What would that theory look like? I think it would look like a Random Utility Model. (...)

A Random Utility model treats human decision-making as if it has two components - a predictable, deterministic component, and a random component. But if there are a huge jumble of behavioral effects going on, it seems to me that outside of the lab, that's usually just going to be observationally equivalent to randomness in the objective function. Which is exactly a Random Utility model.

So what if Random Utility models are the grand unified theory of behavioral economics? What if the upshot of all of these psychological effects is simply that the random component of utility is partially irreducible - that there must be a random component of utility in almost any theory if that theory is going to have a chance of predicting human behavior accurately? Maybe sometimes the randomness is so negligible that people act like homo economicus, and sometimes the random part dominated so much that their decisions are completely unpredictable with science?

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