Yglesias has a run-in with the dregs of humanity: But then lo and behold right by Catania Bakery a couple of dudes ran up from behind, punched me in the head, then kicked me a couple of times before running off. Once, years ago, in Amsterdam a guy threatened me with a knife and took my money. These guys took nothing, and just inflicted a bit of pain. All things considered the threaten/rob model of crime seems a lot more beneficial to both parties than the punch-and-run model. But I guess it takes all kinds. This dude's wry inner economist is one tough SOB. My worst encounter with tsotsis left me pissed and jumpy for weeks afterwards. He continues: To offer a policy observation, higher density helps reduce street crime in an urban environment in two ways. One is that in a higher density city, any given street is less likely to be empty of passersby at any given time. The other is that if a given patch of land has more citizens, that means it can also support a large...