I wonder what the correlation between people who intentionally litter and people who don't return their shopping cart to the corral in parking lots is. I would imagine they overlap a lot.
I think littering probably overlaps with so many other bad behaviours that the punishment should include a lifetime ban on directing a company, being a police officer, practising law, and running for political office.
I imagine it's the same as garbage cans. If the corral is far away, many won't bother. If the parking lot is already full of carts most do the same yet most won't be the first to leave a cart out.