You're right that they won't give up drinking soda! But the experience of Philadelphia, [1] which imposed a per-ounce soda tax (later repealed) shows us that these tend to drive consumers to other jurisdictions (NJ) to buy groceries. This means Philadelphia lost out not only on soda sales, but also on other groceries purchased at the same time.
Another issue that arises is that people will actually transport recyclables across state lines to arbitrage the differences in redemption value. [2] This only happens if there are large enough disparities, but in the US this is almost certain to happen due to the different policy choices made by nearby states.
The thing I don't get about US though......people keep pointing out that US States are as big if not bigger than most European countries - and over there companies somehow manage to create completely unique packaging for every country, distribute their product and keep stock of what's where. Why not in the US? If this sort of thing is enough of an issue, why not make sure that each state gets different barcode, or slightly different label or whatever, to make sure the bottles are not returnable between state lines?
Germany pays a lot more for cans and bottles than Poland does, but you can't return Polish bottles and cans in German stores because the barcodes and labels are different - you can cross the border without any issue, but there is no way to exploit the economic imbalance in recyclables returns.
While I see your point about how to solve this problem, why is this even a problem "worth" solving? Going back to the nuts and bolts: are the bottles and cans any different between countries? What is exactly protected from accepting "foreign" recyclable materials? In a free market, if people start dropping over the border to recycle, local price would quickly match up to avoid people having to make the trip (somebody would make a business out of it, and then original deposit price would soon match up with where it's more expensive).
It rather seems to be the other way around: it's easier to devise a system where you go by something unique and country-specific like a bar-code (to avoid counterfeiting business), so that's why it's like that (of course, there's also living standard difference between countries).
Still, even if there was an incentive discrepancy, it's easy for all the countries to match upward since this is basically just "loaning" bottles/cans out, and you only need to pay out "once" for your regular supply of whatever drinks you like to get, and after that, you are just re-starting the "loan".
FWIW, it's been like that in Serbia since forever, but only for the same product where the producer cared (you'd get an entire beer case, and then once you are through it, you bring it back to the store, and pick up another one): this allowed them to keep the price down and get more turnaround for their drinks.
I sure prefer the legal framework that allows returning it regardless of the specifics (producer or such).
This did actually happen with bottled water- New York State started charging 5-cent deposits on plastic disposable bottled water, and so now some bottled-water companies sell bottles in non-deposit states with different labeling and barcodes. That seems like an exception though, since it's not often the case with other deposit beverages.
The weird one to me is that- due to various archaic laws- in New York state carbonated hard cider in cans or bottles is not considered the same as other carbonated alcoholic beverages in cans, and is exempt from all the deposits. I'm a bit surprised they haven't changed that one.
No one drove to NJ for groceries, the $5 bridge toll would offset any gains. You’d drive to one of the surrounding counties in PA, provided you lived close enough for the trip to make sense. According to that paper, that happened in about 50% of sales, which is still a net win in terms of reduced consumption.
Very little is “lost” to the city when that happens, because groceries are tax exempt.
Not sure what you think happened with property taxes, but there was no rash of store closings. Due to consumers periodically bulk buying soda at a different chain outlet or otherwise.
They might be reluctant but if there is no other way to get that sugary hit they will do it and eventually it will be just how things are done.