Nassim Taleb: There Are Actually Three Types of Swans


There's the Black Swan Event, the rare, impactful event that in retrospect seems predictable, for which his book is named. And then, he tells James Surowiecki, there is the Gray Swan Event.

"Let me describe what a Gray Swan Event is: It's a bridge that can only handle, say, certain size trucks, say, two-ton trucks. And you know, trucks can be much bigger than that. So all it would take is a couple of those for the bridge to collapse. That would be a Gray Swan."

And then there's the current crisis, which is actually a White Swan Event.

A White Swan for me would be a bridge that can only handle these trucks, of course, and you are certain because you have seen from a helicopter a few big six-ton trucks coming on the highway, and so you know the bridge is going to collapse, it's only a matter of time."

Okay, we follow, but we have two questions: Just how many more colors of swan does Nassim think he can pull out of his pocket? And how are these like birds, again?

New Yorker Currents: Nassim Taleb on Risk and Robustness [NYer]