[dreamdu5t]

The problem is those bias' can only be revealed through action.

No matter what you assert somebody's preference is, the preference is only revealed through action.

You can say me going to football games is not in my best interest, but the fact that I act by going to a football game demonstrates that it is.

[_delirium]

This requires asserting as an axiom that people never make mistakes or get tricked, though, are always aware of all relevant information, and are in possession of an accurate mental model of how their actions are likely to affect themselves and the world. I mean, you can't really infer that someone's preference was to fall off a cliff by the mere fact that they did fall off it; they might not have realized that the cliff was there, among other possibilities.

[dreamdu5t]

> This requires asserting as an axiom that people never make mistakes or get tricked

Not having all the information doesn't negate that I'm the one making the choice. I think you're still referring to "rationality" in the logical sense of 2+2=4 being rational, not in the context of economics.

> I mean, you can't really infer that someone's preference was to fall off a cliff by the mere fact that they did fall off it; they might not have realized that the cliff was there, among other possibilities.

I didn't say all preference is revealed through a single action. I was trying to illustrate that action is the only way to determine preference.

For example, if I have a choice of going to McDonald's or Wendy's, you can't know which one I actually prefer unless I act and choose one over the other (thus preference is ordinal, not cardinal).

If I go to Wendy's, it would be absurd to say that I preferred McDonald's, since I chose to go to Wendy's. Thus, only through action is preference revealed. In the same way, it's absurd to say that someone else made a mistake when they bought an Apple product, because you're speaking of your preferences, since you can't actually know what's going on the head of the other person.

What "rational agent" means in the economic context is, that if Person A goes to Wendy's that says nothing about Person B's preference for Wendy's, since both have free will unlike inanimate objects.