Yes. They are uncertain, though I would contend that the vast majority of times that "negative externalities" come up in political argumentation that there's a certain disingenuousness about the reasoning: usually what counts as "negative" is presumed in such cases even though what is really counted as a negative or not is itself ambiguous. Ultimately the complexity of the subjects discussed most frequently leave so many variables on the table that such discussions seem, at least to me, silly and only serve the speaker's desire to rationalize their position. I do find that the discussion of "negative externalities" is really always from the progressive point of view: the phrase sounds intellectual and progressives tend to like that more than conservatives... modern conservatives have long ago abandoned the Buckley-esque pretentions of erudition and embrace simple in-your-face ignorance as more palatable.
This might not be clear... but I very much liked your response. I skimmed the report that you linked. I think they may have missed something in their analysis. I might be reading it wrong, but I think they've underplayed the transport of physical cash. They do mention it, but I didn't see it really discussed very thoroughly and daily transport of cash in the normal course of business is where I would think the greatest efficiency variances would be found. I kinda got the sense the transport they were talking about was between the mint and the banks and the banks and the mint: essentially the cost of transport to the government itself and not more broadly across the economy. That's not unreasonable for the report if they were trying to figure out the difference from their own perspective rather than the broader economy. However, there's significant transport for businesses that trade with cash. The first ~15 years of my career was spent in the corporate management of a few retail chains and providing professional services to others. Cash management was resource intensive relative to electronic payment processing. In one chain I worked in, armored trucks would do cash pickups from each of our stores daily (and sometimes more) and in many locations we had to have extra security staff to escort cash off the retail floor and watch the cash office (which means more people to transport, etc), not to mention other specialized equipment for dealing with cash (counters, etc). All of the chains I was involved in had some variance of this... at least the trucks showing up.
This might not be clear... but I very much liked your response. I skimmed the report that you linked. I think they may have missed something in their analysis. I might be reading it wrong, but I think they've underplayed the transport of physical cash. They do mention it, but I didn't see it really discussed very thoroughly and daily transport of cash in the normal course of business is where I would think the greatest efficiency variances would be found. I kinda got the sense the transport they were talking about was between the mint and the banks and the banks and the mint: essentially the cost of transport to the government itself and not more broadly across the economy. That's not unreasonable for the report if they were trying to figure out the difference from their own perspective rather than the broader economy. However, there's significant transport for businesses that trade with cash. The first ~15 years of my career was spent in the corporate management of a few retail chains and providing professional services to others. Cash management was resource intensive relative to electronic payment processing. In one chain I worked in, armored trucks would do cash pickups from each of our stores daily (and sometimes more) and in many locations we had to have extra security staff to escort cash off the retail floor and watch the cash office (which means more people to transport, etc), not to mention other specialized equipment for dealing with cash (counters, etc). All of the chains I was involved in had some variance of this... at least the trucks showing up.