Bias comparison · evidence reviewed
Both let a known result reshape a retrospective judgment, but the target is different. Outcome bias changes how good or bad a decision process looks; moral luck changes blame, praise, punishment, or moral responsibility while also depending on the actor's intentions, beliefs, causal role, and controllable risk.
The shortest distinction
| Question | Outcome Bias | Moral Luck |
|---|---|---|
| Core judgment | Was this a good decision or a good decision process? | How blameworthy, praiseworthy, punishable, or morally responsible is the actor? |
| Role of the outcome | A good result can upgrade the perceived quality of the decision; a bad result can downgrade it even when the ex-ante information is held constant. | A harmful or beneficial result can change moral evaluation even when much of the actor's choice is similar, but the effect interacts with intention, belief, negligence, and causal responsibility. |
| Mental-state information | Relevant because beliefs and information shape whether the original process was reasonable, but they are not the defining target of the bias. | Central. What the actor intended and reasonably believed can substantially change blame and can explain part of an apparent moral-luck effect. |
| Best review record | Decision rationale, information set, alternatives, expected values, assumptions, and decision rule recorded before the result. | The same ex-ante record plus intention, belief justification, controllable risk, causal contribution, and the moral judgment being made. |
Decision diagnostic
Name the judgment first: decision quality, moral wrongness, blame, praise, or punishment.
Reconstruct the actor's information, beliefs, intentions, options, and controllable risks before revealing the result.
Imagine a matched counterfactual where the same choice produces the opposite outcome because of luck. Check which judgment changes.
If process quality changes mainly with the result, outcome bias is the closer lens. If blame or responsibility changes, examine moral luck while still checking whether the bad result altered how you interpret the actor's beliefs or negligence.
Same outcome, different bias
Outcome BiasTwo managers approve the same defensible safety procedure; one later experiences an accident and their decision is rated much worse solely because the rare failure occurred.
Moral LuckTwo people take the same negligent risk; only one causes serious harm, and that person receives much more blame or punishment partly because the harmful outcome occurred.
Outcome BiasAn investment process is judged brilliant after a profit and foolish after a loss even when the information and method were identical at the time of choice.
Moral LuckA losing investment is judged less moral or its decision-maker less ethically acceptable than a matched profitable investment, despite comparable intentions and ex-ante reasoning.
Outcome BiasA responder's action is scored as a bad operational decision because the incident escalated, without reconstructing the signals available then.
Moral LuckThe same outcome is used to infer that the responder was morally reckless or deserving of blame, without separating what they knew, intended, controlled, and actually caused.
Retrospective review protocol
Evidence
Comparison reviewed 2026-08-18. The individual bias pages contain their full evidence status and boundary conditions.
