[ (people on earth) * (pain from hair rip) ] < pain.[(people in New York) * (pain of being nuked) ]

I think Okeymaker was actually referring to all the people in the universe. While the number of "people" in the universe (defining a "person" as a conscious mind) isn't a known number, let's do as blossom does and assume Okeymaker was referring to the Level I multiverse. In that case, the calculation isn't nearly as clear-cut. (That being said, if I were considering a hypothetical like that, I would simply modus ponens Okeymaker's modus tollens and reply that I would prefer to nuke New York.)