I don't know how widespread this is, but the grocery stores around here implement this sort of predatory donation tactic where they ask you to give your change to some charity. They do this even if you are paying by credit card and the "change" is just an arbitrary number rather than a set of physical objects that would inconvenience you.
You must either lose money or have a
-1 social interaction with a person. This is the same tactic that bums use except bums are usually filthy cretins that can easily be brushed off as non-human. Grocery store clerks are usually normal people that will trigger the socialization cues in your mammalian neocortex.
Luckily my social interaction score has bottomed out so I am indifferent to further penalty. The girls demonstrate a different coping mechanism in this week's comic.