4 ms·

This is invalid. The numbers calculated are counts of crime incidents, not crime rates. A km^2 block with ten times the population density will have ten times t

This is invalid. The numbers calculated are counts of crime incidents, not crime rates. A km^2 block with ten times the population density will have ten times the number of crimes; this doesn't mean it is ten times more dangerous!

rsync 13y ago
If you scroll down you'll see they adjust for that in a followup graph ...
- throwaway_yy2Di 13y ago
  No, they normalize by land area (km^2).
msellout 13y ago
Crime per km^2 is just as valid as crime per person.
- throwaway_yy2Di 13y ago
  It's valid if you're a square kilometer of dirt and you're afraid of being mugged on.
  - derefr 13y ago
    Or, I suppose, if you're trying to decide which square kilometer of dirt to build apartment complexes on based on projected property value trends (where crime is always a large factor.) These tend to be the people who pay for this sort of data (and thus incentivize its collection), which is why it's put in their terms.
- cbr 13y ago
  If I want to know the chances of someone breaking into my apartment I want the data per-apartment. If I want to know the same for cars I want the data per-car. If I want to know my chance of getting shot I want the data per-person. Overall crimes per person approximates what we care about much better than crimes per unit area.
  - jlgreco 13y ago
    > If I want to know my chance of getting shot I want the data per-person In reality though, it isn't as simple as that. Sure, I don't want to be shot. I also don't want other people to be shot a lot in my neighborhood. If I walk to work and see a car parked on the street has been broken into, that bothers, even though my car is in a secure parking garage. I don't want to be the victim of crime, but I also don't want to live amidst crime. I don't want to see it, I don't want to hear about it, and I don't want to think about it. Crime per km^2 is nearly as important to me as crime per capita.
    - derefr 13y ago
      To put it another way: if you live alone, statistics measured per-person are directly applicable to the chance something will happen to you. If you have a family who lives with you, though, the combined probability distribution of something happening to someone in your household changes quite dramatically.
      - cbr 13y ago
        These are rare events, so the chance of something happening to someone in your family of N is close to N times the chance of it happening to you.
- brown9-2 13y ago
  In 2011, NYC had 0.65 murders per square kilometer (515 murders in 784 sq km of land). In the same year, Gary IN had 0.23 murders per square kilometer (30 murders in 129 sq km of land). Do you feel 2.5 times higher to be murdered in NYC than you do in Gary, IN? For comparison with the traditional per-100,000-people rates, NYC had a rate of 6.3 in 2011 versus 37.2 in Gary.
cobrausn 13y ago
A block with ten times the population density and four times the number of residences that has ten times the number of home break-ins is more dangerous - there are more crime victims. I suppose this means that the type of crime is important.
- deleted 13y ago
  [deleted]
ayoo 13y ago
Good point. Also rich people live in the hills, Of course there is more crime in poorer areas with more density and with less care from police. Just put SF in the title and you'll still get a lot of self-loving sf people to click.
steven2012 13y ago
I live in the low-crime area of SF depicted in the graph, and I can confirm that most definitely there is a much lower population density than in other areas of SF, including places like PacHeights. It is mainly residential, with the houses being roughly 100 years old. Most people in SF that I know have never been to that area, mainly because there's no reason to unless you live there. But then again, the crime rates in Outer Sunset are relatively low as well, and they are at roughly sea level, and they are at stark contrast to SOMA, etc. Mind you, the houses in that area start at $900k for 2br/1ba houses, and 1.2M for 3/2 of reasonable size. There are very large houses as well for $2M+, especially in St. Francis Wood, and Forest Hill.

rsync 13y ago

If you scroll down you'll see they adjust for that in a followup graph ...

throwaway_yy2Di 13y ago
No, they normalize by land area (km^2).

msellout 13y ago

Crime per km^2 is just as valid as crime per person.

throwaway_yy2Di 13y ago
It's valid if you're a square kilometer of dirt and you're afraid of being mugged on.
- derefr 13y ago
  Or, I suppose, if you're trying to decide which square kilometer of dirt to build apartment complexes on based on projected property value trends (where crime is always a large factor.) These tend to be the people who pay for this sort of data (and thus incentivize its collection), which is why it's put in their terms.
cbr 13y ago
If I want to know the chances of someone breaking into my apartment I want the data per-apartment. If I want to know the same for cars I want the data per-car. If I want to know my chance of getting shot I want the data per-person. Overall crimes per person approximates what we care about much better than crimes per unit area.
- jlgreco 13y ago
  > If I want to know my chance of getting shot I want the data per-person In reality though, it isn't as simple as that. Sure, I don't want to be shot. I also don't want other people to be shot a lot in my neighborhood. If I walk to work and see a car parked on the street has been broken into, that bothers, even though my car is in a secure parking garage. I don't want to be the victim of crime, but I also don't want to live amidst crime. I don't want to see it, I don't want to hear about it, and I don't want to think about it. Crime per km^2 is nearly as important to me as crime per capita.
  - derefr 13y ago
    To put it another way: if you live alone, statistics measured per-person are directly applicable to the chance something will happen to you. If you have a family who lives with you, though, the combined probability distribution of something happening to someone in your household changes quite dramatically.
    - cbr 13y ago
      These are rare events, so the chance of something happening to someone in your family of N is close to N times the chance of it happening to you.
brown9-2 13y ago
In 2011, NYC had 0.65 murders per square kilometer (515 murders in 784 sq km of land). In the same year, Gary IN had 0.23 murders per square kilometer (30 murders in 129 sq km of land). Do you feel 2.5 times higher to be murdered in NYC than you do in Gary, IN? For comparison with the traditional per-100,000-people rates, NYC had a rate of 6.3 in 2011 versus 37.2 in Gary.

cobrausn 13y ago

A block with ten times the population density and four times the number of residences that has ten times the number of home break-ins is more dangerous - there are more crime victims. I suppose this means that the type of crime is important.

deleted 13y ago
[deleted]

ayoo 13y ago

Good point. Also rich people live in the hills, Of course there is more crime in poorer areas with more density and with less care from police. Just put SF in the title and you'll still get a lot of self-loving sf people to click.

steven2012 13y ago

I live in the low-crime area of SF depicted in the graph, and I can confirm that most definitely there is a much lower population density than in other areas of SF, including places like PacHeights. It is mainly residential, with the houses being roughly 100 years old. Most people in SF that I know have never been to that area, mainly because there's no reason to unless you live there. But then again, the crime rates in Outer Sunset are relatively low as well, and they are at roughly sea level, and they are at stark contrast to SOMA, etc. Mind you, the houses in that area start at $900k for 2br/1ba houses, and 1.2M for 3/2 of reasonable size. There are very large houses as well for $2M+, especially in St. Francis Wood, and Forest Hill.