>>2058080nta and I can see it going either way on the claimed reduction in crime, but I think this is a kind of broken window theory combined with nudge theory. you have a lot of people who serve as onlookers. you have a small group of potential troublemakers, who will always do crime no matter what. and you have an even smaller group of marginal people who might be tempted to do a crime, but it depends on what mood they're in.
the precursor to this is when they enter the environment in question, you either prime them as "criminals" by presenting a fare collection contraption to disobey to the pearl-clutching of onlookers, or you don't do so, no pearls get clutched, and their psychological state remains as it was. it won't make a difference in 99.9% of cases, but it only takes 0.1% to make a blip in the overall number of stabbings or whatever. or so the theory might go.
now it should be noted that this is widely considered a racist, right-wing, gentrifying, classist, pro-prison-industrial-complex, highly problematic theory of criminal justice. so it is interesting to see right wingers do a 180 and oppose it this time, because this time it came in a proposal raised by a supposed libtard bleeding heart commie. but we've seen a lot of things like this lately, people abandoning their principles in favor of tribal loyalty.