It has been 15 years now since the people of San Francisco effectively abolished capital punishment on a local basis by electing DAs who never seek it, not even for people who murder police officers or children. So how has the City by the Bay done in its homicide rate, relative to the rest of the state?
Until the late 1990s, the murder rate of SF generally tracked that of the state as a whole. It tended to be somewhat above the statewide rate, and there was a spike in 92-93. For 89-98, San Francisco was on average 12.5% above the state as a whole. From 1999 to 2003, San Francisco pulled away from the statewide rate and was persistently higher, 28.8% higher on average. For 2004-2008, San Francisco's homicide rate jumped while the state's declined. The SF rate is a whopping 84% higher for the 5 year range and more than double in 2007 and 2008. Preliminary data for 2009 do show a substantially larger drop for SF than for the state as a whole, but not enough to bring it back into the ratio it had circa 1990.
What should we make of the long term trend diverging from the state several years after the change in policy and persisting and expanding as time goes on? The trend is consistent with my hypothesis of how deterrence works. That is, it is a general awareness among the crime-prone whether the jurisdiction does or does not have the death penalty and, if it does, whether it does or does not enforce it. Many studies in the area measure only the recency effect, measuring change shortly after a publicized execution, for example. I think the long-term effect is the more important one.
Of course, we can't draw definite conclusions from this one example. There are way too many uncontrolled variables. This is more of an illustration than a proof. Still, the piece fits in the overall puzzle.
The data are from the California Criminal Justice Statistics Center annual Homicide in California series.
Until the late 1990s, the murder rate of SF generally tracked that of the state as a whole. It tended to be somewhat above the statewide rate, and there was a spike in 92-93. For 89-98, San Francisco was on average 12.5% above the state as a whole. From 1999 to 2003, San Francisco pulled away from the statewide rate and was persistently higher, 28.8% higher on average. For 2004-2008, San Francisco's homicide rate jumped while the state's declined. The SF rate is a whopping 84% higher for the 5 year range and more than double in 2007 and 2008. Preliminary data for 2009 do show a substantially larger drop for SF than for the state as a whole, but not enough to bring it back into the ratio it had circa 1990.
What should we make of the long term trend diverging from the state several years after the change in policy and persisting and expanding as time goes on? The trend is consistent with my hypothesis of how deterrence works. That is, it is a general awareness among the crime-prone whether the jurisdiction does or does not have the death penalty and, if it does, whether it does or does not enforce it. Many studies in the area measure only the recency effect, measuring change shortly after a publicized execution, for example. I think the long-term effect is the more important one.
Of course, we can't draw definite conclusions from this one example. There are way too many uncontrolled variables. This is more of an illustration than a proof. Still, the piece fits in the overall puzzle.
The data are from the California Criminal Justice Statistics Center annual Homicide in California series.
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