Question about your hypothetical: What happens if less than the necessary number of people volunteer for the dust speck? Do they A) get the dust speck to no purpose, or B) is their speck count reduced as though they hadn't volunteered?

I wouldn't volunteer either way, if you ignore irrational guilt trips like ArisKatsaris said. If there are 3^^^3 volunteers, they are irrational in situation B, and probably in situation A as well.