Statistical Knowledge Deconstructed
Kenneth W. Simons, Statistical Knowledge Deconstructed, 92 B.U. L. Rev. 1 (2012).
The law frequently distinguishes between individualized knowledge, or awareness that one’s act will harm a particular victim, and statistical knowledge, or awareness that one’s activity or multiple acts will, to a high statistical likelihood, harm one or more persons from a large class of potential victims. (Compare driving through an intersection while aware that one’s automobile is likely to injure a pedestrian in the crosswalk with managing a large construction project that one confidently predicts will result in worker injuries.) Under tort and criminal law doctrine, acting with individualized knowledge is ordinarily much more difficult to justify and, if unjustified, much more culpable than acting with statistical knowledge. Yet the distinction is remarkably difficult to explain and defend.
This Article – the first systematic analysis of this pervasive but underappreciated problem – offers a qualified defense of the distinction between individualized and statistical knowledge. Acting with statistical knowledge is ordinarily less culpable than acting with individualized knowledge, and it is often not culpable at all. Expanding the spatial or temporal scope of an activity or repeating a series of acts sometimes causes the actor to acquire statistical knowledge, but such an expansion in scale ordinarily does not increase the level of culpability properly attributable to the actor. Two invariant culpability principles, “invariant culpability when acts are aggregated” and “invariant culpability when risk-exposures are aggregated,” formalize this idea.
Why is acting with individualized knowledge especially culpable? Part of the answer is the special stringency principle (SSP), a deontological principle that treats an actor as highly culpable and treats his acts as especially difficult to justify when he knowingly imposes a highly concentrated risk of serious harm on a victim. Under SSP, it is much harder to justify (a) speeding to the hospital to save five passengers, with knowledge that this will very likely require killing a pedestrian in one’s path, than (b) speeding to the hospital to save one passenger, with knowledge that this creates a 20% chance of killing a pedestrian in one’s path.
The analysis has a number of significant implications but is also subject to important qualifications:
- Notwithstanding the invariant culpability principles, if a faulty or unjustified actor repeats his acts or expands his activity, that repetition sometimes reveals a new type of culpability: the defiance of moral and legal norms. Accordingly, a retributivist can indeed support a punishment premium for recidivists.
- In rare cases, when the actor possesses merely statistical knowledge but his conduct is extremely unjustifiable, the actor’s culpability is comparable to that of an actor with individualized knowledge.
- If an actor conducts a cost-benefit analysis of a planned activity and thereby acquires statistical knowledge that the activity will cause serious harm, his decision to proceed with the activity in the face of such knowledge does not, by itself, demonstrate that the activity is unjustifiable or that he is culpable for so proceeding.
- A legal system can be legitimate even though legal actors within the system know that it will, as a statistical matter, punish the innocent.
- The higher culpability of acting with individualized knowledge is not explained by a supposed higher duty owed to “identifiable victims,” except insofar as that duty is a crude version of SSP.