Re: Most Dangerous States, now "43 times"
- Original Message - From: "David Hobby" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" <[EMAIL PROTECTED]> Sent: Sunday, August 10, 2003 11:42 PM Subject: Re: Most Dangerous States, now "43 times" > Robert Seeberger wrote: > ... > > Evaluating the "43 times" fallacy > > ...a study by Arthur Kellermann and Donald Reay published in the > > June 12, 1986 issue of New England Journal of Medicine (v. 314, n. 24, p. > > 1557-60) which concluded that a firearm in the home is "43 times more > > likely" to be used to kill a member of the household than to kill a criminal > > intruder. > > Most of the criticisms are valid, but there are a couple of > flaws. (I've snipped all but the flaws.) > > ... > > How many successful self-defense events do not result in death of the > > criminal? An analysis by Gary Kleck and Marc Gertz (Journal of Criminal Law > > and Criminology, v. 86 n.1 [Fall 1995]) of successful defensive uses of > > firearms against criminal attack concluded that the criminal is killed in > > only one case in approximately every one thousand attacks. > > But this isn't fair either, since the intent of the criminal is > unknown. The factor of 1000 is used as if all of these were prevented > homicides. A large fraction were probably "prevented burglaries", > which should not be counted as high as human life. (Possessing a gun > would have to foil MANY burglaries for that to be worth a sizable > risk of killing a family member!) > > ... > > "Reverse causation" is a significant factor that does not lend itself to > > quantitative evaluation, although it surely accounts for a substantial > > number of additional homicides in the home. A person, such as a drug dealer, > > who is in fear for his life, will be more likely to have a firearm in his > > home than will an ordinary person. Put another way, if a person fears death > > he might arm himself and at the same time be at greater risk of being > > murdered. Thus Kellermann's correlation is strongly skewed away from normal > > defensive uses of firearms. His conclusion is thus no more valid than a > > finding that because fat people are more likely to have diet foods in their > > refrigerators we can conclude that diet foods "cause" obesity, or that > > because so many people die in hospitals we should conclude that hospitals > > "cause" premature death. Reverse causation thus further lowers the 0.006 > > value, but by an unknown amount. > > This is often called a "confounding variable", one factor that > increases the likelihood of both the "cause" (explanatory) and the > "effect" (response) variables in a study. They seem to be proposing > "fear of death by homicide" as a confounding variable, but it is > not stated very clearly. > One can successfully argue for some connection here. > Certainly people at high risk of being killed by homicide tend to > know this. And if one is "afraid of homicide", one is more likely > to shoot people without carefully verifying they are strangers, > leading to more accidental killings of family members. > But it doesn't seem to me to be a very strong effect, and > it could well be countered by people in an armed household knowing > enough not to do things like "climb in the window when you forget > your keys, rather than knock and wake everybody up". > I wish I'd seen this one first: http://www.guncite.com/gun_control_gcdgaga.html xponent The Mood Struck Me Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: Most Dangerous States, now "43 times"
- Original Message - From: "David Hobby" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" <[EMAIL PROTECTED]> Sent: Sunday, August 10, 2003 11:42 PM Subject: Re: Most Dangerous States, now "43 times" > Robert Seeberger wrote: > ... > > Evaluating the "43 times" fallacy > > ...a study by Arthur Kellermann and Donald Reay published in the > > June 12, 1986 issue of New England Journal of Medicine (v. 314, n. 24, p. > > 1557-60) which concluded that a firearm in the home is "43 times more > > likely" to be used to kill a member of the household than to kill a criminal > > intruder. > > Most of the criticisms are valid, but there are a couple of > flaws. (I've snipped all but the flaws.) > > ... > > How many successful self-defense events do not result in death of the > > criminal? An analysis by Gary Kleck and Marc Gertz (Journal of Criminal Law > > and Criminology, v. 86 n.1 [Fall 1995]) of successful defensive uses of > > firearms against criminal attack concluded that the criminal is killed in > > only one case in approximately every one thousand attacks. > > But this isn't fair either, since the intent of the criminal is > unknown. The factor of 1000 is used as if all of these were prevented > homicides. A large fraction were probably "prevented burglaries", > which should not be counted as high as human life. (Possessing a gun > would have to foil MANY burglaries for that to be worth a sizable > risk of killing a family member!) > > ... > > "Reverse causation" is a significant factor that does not lend itself to > > quantitative evaluation, although it surely accounts for a substantial > > number of additional homicides in the home. A person, such as a drug dealer, > > who is in fear for his life, will be more likely to have a firearm in his > > home than will an ordinary person. Put another way, if a person fears death > > he might arm himself and at the same time be at greater risk of being > > murdered. Thus Kellermann's correlation is strongly skewed away from normal > > defensive uses of firearms. His conclusion is thus no more valid than a > > finding that because fat people are more likely to have diet foods in their > > refrigerators we can conclude that diet foods "cause" obesity, or that > > because so many people die in hospitals we should conclude that hospitals > > "cause" premature death. Reverse causation thus further lowers the 0.006 > > value, but by an unknown amount. > > This is often called a "confounding variable", one factor that > increases the likelihood of both the "cause" (explanatory) and the > "effect" (response) variables in a study. They seem to be proposing > "fear of death by homicide" as a confounding variable, but it is > not stated very clearly. > One can successfully argue for some connection here. > Certainly people at high risk of being killed by homicide tend to > know this. And if one is "afraid of homicide", one is more likely > to shoot people without carefully verifying they are strangers, > leading to more accidental killings of family members. > But it doesn't seem to me to be a very strong effect, and > it could well be countered by people in an armed household knowing > enough not to do things like "climb in the window when you forget > your keys, rather than knock and wake everybody up". > http://www.guncite.com/gun_control_gcdguse.html There are approximately two million defensive gun uses (DGU's) per year by law abiding citizens. That was one of the findings in a national survey conducted by Gary Kleck, a Florida State University criminologist in 1993. Prior to Dr. Kleck's survey, thirteen other surveys indicated a range of between 800,000 to 2.5 million DGU's annually. However these surveys each had their flaws which prompted Dr. Kleck to conduct his own study specifically tailored to estimate the number of DGU's annually. Subsequent to Kleck's study, the Department of Justice sponsored a survey in 1994 titled, Guns in America: National Survey on Private Ownership and Use of Firearms (text, PDF). Using a smaller sample size than Kleck's, this survey estimated 1.5 million DGU's annually. There is one study, the National Crime Victimization Survey (NCVS), which in 1993, estimated 108,000 DGU's annually. Why the huge discrepancy between this survey and fourteen others? Dr. Kleck's Answer Why is the NCVS an unacceptable estimate of annual DGU's? Dr. Kleck states, "Equally important, those who take the NCVS-based estimates seriously have consistently ignored the mos
Re: Most Dangerous States, now "43 times"
Robert Seeberger wrote: ... > Evaluating the "43 times" fallacy ...a study by Arthur Kellermann and Donald Reay published in the > June 12, 1986 issue of New England Journal of Medicine (v. 314, n. 24, p. > 1557-60) which concluded that a firearm in the home is "43 times more > likely" to be used to kill a member of the household than to kill a criminal > intruder. Most of the criticisms are valid, but there are a couple of flaws. (I've snipped all but the flaws.) ... > How many successful self-defense events do not result in death of the > criminal? An analysis by Gary Kleck and Marc Gertz (Journal of Criminal Law > and Criminology, v. 86 n.1 [Fall 1995]) of successful defensive uses of > firearms against criminal attack concluded that the criminal is killed in > only one case in approximately every one thousand attacks. But this isn't fair either, since the intent of the criminal is unknown. The factor of 1000 is used as if all of these were prevented homicides. A large fraction were probably "prevented burglaries", which should not be counted as high as human life. (Possessing a gun would have to foil MANY burglaries for that to be worth a sizable risk of killing a family member!) ... > "Reverse causation" is a significant factor that does not lend itself to > quantitative evaluation, although it surely accounts for a substantial > number of additional homicides in the home. A person, such as a drug dealer, > who is in fear for his life, will be more likely to have a firearm in his > home than will an ordinary person. Put another way, if a person fears death > he might arm himself and at the same time be at greater risk of being > murdered. Thus Kellermann's correlation is strongly skewed away from normal > defensive uses of firearms. His conclusion is thus no more valid than a > finding that because fat people are more likely to have diet foods in their > refrigerators we can conclude that diet foods "cause" obesity, or that > because so many people die in hospitals we should conclude that hospitals > "cause" premature death. Reverse causation thus further lowers the 0.006 > value, but by an unknown amount. This is often called a "confounding variable", one factor that increases the likelihood of both the "cause" (explanatory) and the "effect" (response) variables in a study. They seem to be proposing "fear of death by homicide" as a confounding variable, but it is not stated very clearly. One can successfully argue for some connection here. Certainly people at high risk of being killed by homicide tend to know this. And if one is "afraid of homicide", one is more likely to shoot people without carefully verifying they are strangers, leading to more accidental killings of family members. But it doesn't seem to me to be a very strong effect, and it could well be countered by people in an armed household knowing enough not to do things like "climb in the window when you forget your keys, rather than knock and wake everybody up". ---David Where was this when I was still teaching my Statistics class? ___ http://www.mccmedia.com/mailman/listinfo/brin-l
