At first, behavioral economics denies economic expert. Economic expert is the people who act in utilitarian way.
The reason of denying that traditional economics does not consider the cost to act in utilitarian way. The cost is to collect data. It is the lack of economic view. And in practical case, we cannot collect perfect data for utilitarian action.
Then behavioral economics considers that "We do not do perfect utilitarian action. We do limited utilitarian action."
In limited utilitarian action, habits affect strongly. Those habits are framing effect, heuristics and bias. Behavioral economics studies the relationship between these habits and economic system.
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