“black swan” events—defined as “unexpected and low-probability events with massive repercussions.”13 Nassim Nicholas Taleb, the best-selling author who popularized the term, points to the Harry Potter books, the spread of the internet, and calamities such as WW I as examples of events that were nearly impossible to predict but have had huge

I stop and summarize the triplet: rarity, extreme impact, and retrospective (though not prospective) predictability.