Originally Posted by
bungeebungee
In the sense of a tourist visiting, say, New York, they don't seem to. Some part of that may be because of the very population density you mentioned. I apologize in advance for a rambling answer, I'm a few cups of coffee short.
Let's take the area where I rent as an example. I live in a very ordinary apartment complex about half way out between the city center and the edges of the city itself. It isn't a fancy place, and the potential problems seem typical.
Rent is steep in Beijing and there is a large migrant population. Many areas that were once intended for storage and emergency shelter have been converted to warrens of single rooms. My complex is convenient to the subway, and no exception. There are quite a few people living largely out of sight in a place you probably wouldn't know about, an area under the apartments. How many people live there? I don't know and I doubt the government does either, but a thousand wouldn't surprise me. The main entrance is an unmarked door sort of behind a dry cleaner. Similarly, the area next to the subway tracks is sort of park like, but it isn't unusual for groups working construction to pitch tents there. These are two potentially rough groups, but I have no worries if I'm out at night and carrying the equivalent of a month's pay for them in cash without so much as a pocket knife or pepper spray. That holds equally true at 1500 or 0300.
Consider that many people living in one area. Even at 0300 I may bump into small groups of elderly Chinese taking in a breeze and gossiping away, that's an activity as dear to them as granny dancing. Beyond the gossipy grannies, at any given time, there will be people out cleaning the streets, and others using the quiet hours of early morning to make deliveries or to pick stuff up. How does any of this reduce crime? Anyone committing a crime, or just being a jackass, is apt to find their face all over social media because there are lots of bored people out there, and most have phones. These aren't sinister government snitches observing people, these are just folks who want their 15 minutes of fame for posting a video that might get hits.
What about the rent a cops I mentioned? They are much like rent a cops around the world. They're there to protect property, whether is apartments, a school, or a mall. In between naps and playing with their phones, they'll bestir themselves to do a lap or two on an electric scooter. Still, presence is presence, and those electric scooters can be very silent.
Probably a more significant factor that might explain why there aren't bad areas is that Beijing has expanded so quickly that really shady areas just haven't had a chance to develop. Those rent a cops are protecting things because property in Beijing can cost 100, 000 RMB ... per square meter. Give it a few decades and real shady areas may spring up. For now, they haven't.
Do I claim that there is no crime? Oh, hells no! Would I tell you not to go to a popular pedestrian area downtown? No, but I would tell you to avoid 'helpful' young women, working in pairs, who will offer to assist you with a thousand things like visiting an art gallery because they are probably not the innocent, dewy eyed students the claim to be and they're probably shills who get about 60% of the money they get you to spend. Similarly, I wouldn't tell you that the main airport is in a bad area, but I would tell you to use a shuttle bus or the special subway branch instead of taking a taxi that might have a rigged meter or a driver who finds ways to drive you all over the place to run up the fare. I wouldn't tell you to avoid coffee shops as a hotbed of crime, but I would tell you not to leave your phone on the table while you aren't there.
Bad areas? Not so much. Dumb moves? Those exist.