Black Swans and the Challenge of Mitigating the Unknown

By Bob Raffel

 It is again important to note that these are illustrative examples, not meant to be considered all-inclusive or universally applied across the spectrum of school campuses – college, public or private - in the U.S. They provide a measure of what Nissan Taleb refers to as “prevention” and “robustness”. In their totality, addressing vulnerabilities such as the ones above provide a level of resiliency to school operations. Moreover, they are areas where data, albeit sparse, do exist. Attempts to “explain” school shooting events, even if successful (i.e., we discover what drove Adam Lanza to kill 27 people) are seldom instructive. Likewise, our ability to predict such events is limited, if it exists at all. What we are left with then, is a focus on those areas we know experientially or can deduce logically. These may involve the physical vulnerabilities of schools and classrooms, administrative and/or emergency procedures and targets. Applying mitigation measures to these “known” weaknesses results in a net gain; a hardening of the targets attractive to the school shooter. This approach is far more likely to achieve results than endless discussions about “motive” (the why) or personal characteristics (the who) or choice of location and weapons (the where and what) of people who perpetrate such atrocities. It is rather, a focus, as Nassim Taleb says, on the “relevant eventualities”.


School shootings, although occurring at an increasing rate, are uncommon and unpredictable. As such, they might be classified as “Black Swans”, events which are random yet produce extreme impacts. To the extent that this is so, traditional risk assessment methods are of limited usefulness. It is perhaps more productive to focus on what is known about such attacks (i.e., physical, administrative and procedural vulnerabilities, targets) and direct mitigation measures accordingly. Lacking a predictive capability, our focus should be on prevention, robustness and resiliency.

Bob Raffel is an associate professor in the homeland security program at Embry-Riddle Aeronautical University. For the last six years he's been teaching a course he developed on critical infrastructure protection and risk analysis.



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