Expected utility
Assumptions
Actors have fixed, complete and transitive preferences over a set of outcomes.
- Completeness: All pairs of consequences are compared
- Transitivity: This means that preferences do not contradict themselves If you like A more than B, and you like B more than C, then it would be inconsistent to say you like C more than A. Transitivity says instead, that you must like A more than C.
Calculation
The expected utility for action is calculated by multiplying the probability of each outcome with its utility. In other words, the utilities are weighted by their probability and summed up.
- Three outcomes ()
- = probabilities for the respective outcomes
- = utility of an outcome
Example: Utility of voting