Danger: a situation in which harm, death, damage, or destruction is possible (Macmillan Dictionary)
Well, that’s a beginning - though overly broad and ambiguous. What I have in mind is more specific: the danger of being a victim of violent or physically threatening behavior, as in homicide, rape, sexual assault, aggravated assault and simple assault. So wouldn’t a city’s violent crime rates be the best indicator of how dangerous it is? Not necessarily. Crime rates are calculated by dividing the number of reported crimes by the total population, then multiplying the result by 100,000. But there’s also crime density, or the amount of crime in a specific geographic locale. Crime density is typically measured as number of crimes in a year divided by square miles of the population unit, e.g., a city. These two ways of measuring crime can give quite different impressions of how dangerous a city is. For example…
So if I were to walk a random 10-acre area in Houston and San Francisco, which city would be more dangerous for me personally, considering only violent crime rate and crime density? San Francisco.
But there’s a problem with the above charts: they are based on the FBI’s figures on violent crime, which leave out simple assaults. Luckily, the Bureau of Justice Statistics includes simple assault in its annual crime victimization reports. Plus last year a violent victimization survey was conducted in San Francisco and it also (implicitly) included simple assault as a form of violence in the question, “During the past five years, did anyone ever threaten you or attack you physically, or did that not happen to you during that time?” Take a look:
Granted, the national and San Francisco surveys don’t cover exactly the same types of violence. For example, a person robbed in San Francisco may not see herself as having been “physically attacked” (the robber may have asked nicely and didn’t threaten to use his gun). And the San Francisco survey’s use of “threaten” is ambiguous and may not have counted as simple assault in the national survey, e.g., a threatening phone call. Also, “victimization” is not the same as “victim”, as a single person can be victimized more than once in the same year. But what that means is that the number of simple assault victims in the national report would be smaller than the number of victimizations, which was 10.9 per 1000 respondents.
Still, between crime density and the self-report survey, San Francisco doesn’t seem particularly safe to me. Of course, whether it’s actually dangerous depends on time of day and where you are in the city. And whether you look like an easy mark.