A bonus based on damage/late customer reports on boxes that passed through the facility is more likely to work than simply increasing base. Put everyone’s (extra) cash on the line and aligned with customer outcomes.

Sort of a tragedy-of-the-commons bonus, then? Individual employees have the power to block bonuses, but not the power to ensure that they are not blocked, under this plan.

More likely a community policing of the commons. It’s not like Joe is secretly taking a package into the men’s room and smashing it. He’s doing it in full view and awareness of his co-workers in all likelihood. “Hey Joe, stop that, you’re killing our bonus!”

I'm willing to bet UPS has calculated this.

Yes.