My takeaway: Sometimes people don’t behave in aggregate the way we think they should. By replacing their money with money\k and convincing them it’s still just money, we can manipulate their behavior by jiggling k.*
And it apparently goes without saying that the coupon-issuer has a good way to distinguish “legitimate” reasons to cut back on going out. E.g., flu outbreak, new compelling indoor family activity, all the other stuff no one’s even thought of yet, etc.
The Keynesian “key to enlightenment” is that we can cram a knob onto the economy and jack with it?
I’d be interested in reading more about your top ten cool possibilities. They sound cool.