My Hypothesis of Collective Imprudence may have an unhappy corollary: When the human race (or some largish subset of it) really does get its collective act together to avert a foreseen evil, the evil is likely imaginary. This is the Corollary of Misplaced Collective Prudence. A sapient reader offers the most recent illustration.

“Mr. Derbyshire—As noted by your other sophist emailers, it is not feasible to come up with a counter-example to HCI in which mankind collectively acted prudently and successfully avoided a catastrophe.
“I believe, however, I can think of one instance in which mankind acted collectively to prepare for an anticipated catastrophe that never materialized (and had egg on their collective faces accordingly) … the Y2K scare.
“Throughout the world, people were purchasing power generators, taking out obscene quantities of cash to cover for all of the ATM machines that were certain to fail, and preparing for the inevitable looting and mayhem that would occur when power and security systems failed around the globe.
“I’m not sure if widespread advance-panic counts at all in the context of HCI, but it seems to me that a little healthy collective imprudence during the Y2K nonsense could have helped all of mankind to come out of that time looking a bit less silly.”

[Derb] More to the point as far as this old COBOL programmer is concerned, the Y2K scare marked the last point at which that particular skill was marketable. Since then I’ve had to seek other employment….