Hey! There's a new poll (eco-pets!) on the right sidebar ==>
When it comes to making mistakes (counting change at the check out, bargaining over goods, buying high and selling low), I tend to...
...be a taker (taking in more than I give away)
...be a giver (giving away more than I take in)
...not pay attention
...change depending on whether it's work or play
...offset give and take with karma
68 votes total
Karma. I like the karma answer. I tend to "keep the change" when given too much because I consider that gain to be a wealth transfer from innumerate to numerate people. OTOH, I am quick to leave a heavy tip for people who give me a break (in times of discretion), especially when it's out of their own pocket.
I especially like spending a windfall on treats for other people.
Bottom Line: Humans are social animals who like to share the joy (as well as the pain). In these cases, the economics (insurance) are reinforced by the psychology (care and concern).