But this is based on crime enforcement stats, not underlying incidence of the crimes themselves. There are areas of SF (like the park over at Haight and Ashbury) where these laws basically aren't enforced. Thus: perhaps not a great map for where to find drugs.
Prostitution may be similar; there seem to be areas in every city where it's practiced openly and brazenly, which tells me there's a sub rosa understanding between law enforcement and prostitutes.
(Note also that "drugs" here probably means "vials", and "prostitution" here probably means "street hookers").
Yeah, that's a really important distinction to keep in mind. I work a lot with crime data, and so people say things like "Oh, so you know all the best places to find drugs", when in reality what I know is the best places to get caught. Where people are committing crimes and where they are getting arrested may or may not be the same.
For San Francisco all the crime data is published (well, other than some sensitive data like the locations of rapes). datasf.org has a listing of all the geospatial data available for SF. A lot of other cities have their own data repositories. Washington DC has one of the best (http://data.dc.gov/) and New York has a good catalog as well (http://www.nyc.gov/html/datamine/html/data/data.shtml).
I don't think this map is easy to read at all. 3D projections onto 2D lose information; especially this one. A colored overlay (like weather radar) or contour lines (like a topographical map) would be much easier to understand.
What's also interesting is that that seems to confirm the East-side theory about cities (at least for San Francisco) mentioned here a couple of weeks ago:
The east-side theory predicts the geographical distribution of property values and of low-income households. These maps plot the distribution of crime as measured by arrests. Poverty and crime are not the same thing.
They seem, unfortunately, correlated. Certainly, there isn't any easy causal relationship. And actually, looking at it more -- I may be wrong. Here's a real-estate price map for San Francisco:
But by the logic of the westerly (east-blowing) winds, however, places in SF like Hunters Point, etc., were probably not as attractive real estate locations originally, and probably that led to some vicious cycles, etc.
Prostitution may be similar; there seem to be areas in every city where it's practiced openly and brazenly, which tells me there's a sub rosa understanding between law enforcement and prostitutes.
(Note also that "drugs" here probably means "vials", and "prostitution" here probably means "street hookers").