Scandinavia and the World

Comments #9823074:

Armed to immobilize 9 10, 6:03pm

@Isdaril "But my point was that I don't think those successses outweight the times when you end up with one dead person or even two (maybe I'm wrong though as I've got no idea about the frequency of both those events chances of happening)."
Earlier we've seen the claim (link about various studies of defensive gun use) where it was estimated that number of gun self-defense episode is at least in tens of thousands per year, at very least. Two more points for comparison:
Point one: "In 2012, there were only 259 justifable homicides involving a gun. For the fve-year period 2008 through 2012, there were only 1,108 justifable homicides
involving a gun. [For additional information see Table One: Firearm Justifable Homicides by State, 2008-2012.]"
Point two: FBI shows number of 12765 murders in 2012, of those 8855 committed with firearms (predominantly handguns).
To me the fact that lowest estimate of defensive use is greater than total number of homicides (justifiable, which include some of the shooting by police, and not) indicates that lethality of most self-defense situations is not that high.
From anecdotal evidence I'd say that mutual death is very unlikely, whoever is getting hit first isn't going to return effective fire.

"it could also prompt the future agressors to carry more weapons and be more ready to use them when attempting this kind of offense because they know they could get caught or killed otherwise"
Extra weapons will not improve outcome for criminal. Switching knife for a handgun may improve chances somewhat, but using it requires commitment to a more severe crime. If victim successfully resists the attempt of robbery, it's safer to run away and try someone else than to kill the victim and risk 20 years to life in prison for murder.
Not only prison sentence is greater, there will be more effort put into investigation . There is both practical and psychological barrier to that kind of escalation. Well, unless it happens in place like Baltimore.

"I would argue that this is debatable only if you think that injuries or rape are worse than death"
As an old Soviet joke says "terrible end is better than endless terror".
Non-sexual assault or violent rape often result in psychological and physical damage that may affect victim for the rest of life. Set of outcomes (victim being strangled or beaten to a point of brain damage, trauma resulting in full paralysis or extreme disfigurement, certain kinds of organ damage, etc.) is literally worse than death because they means victim will spend the rest of life in suffering.
There is a wider set of outcomes that is, technically, not as bad, but requires long process of rehabilitation and may still affect the rest of victim's life. Worst case scenario is that psychological damage leads to suicide or heavy substance abuse which, practically speaking, are almost the same.

" (because every life is worth the same on an utilitarian PoV)"
I will disagree with that. "Worth" implies either economic or moral judgement, both of those which are generally not on criminal's side. Well, I can think of few moral exceptions, but they're not really applicable for regular criminal activity.

"And there are a lot of cases you're omitting which are offences without violence in which case having a gun for self-defense has almost always negative utility."
Armed self-defense within the limits of the law necessarily requires reasonable fear of death or serious injury, even if in some places that rule is relaxed for cases of defense against home invasion. Cases where no threat of violence exists are omitted from an argument about self-defense by definition.

"that have cases of violence which represents only 8% of the total of burglaries. On those 8%, only 10% of cases do end up with people with serious injuries so a little less than 1%, making my case all the more stronger, because it seems that non-violent offenses are the norm and violent ones the exception."
Or, to put it in perspective, burglaries resulted in approximately 1.6 thousand rapes and 5.6 thousand serious injuries per year. While percentages are small, overall number of home invasions is vast. While most of those do not require armed self-defense, those that do are important. Threat of armed self-defense in minor cases means that either police can be notified in time or at least crime in progress can be stopped, in serious cases that means victim is not getting raped or tortured.

"Ultimately I agree that it is debatable, but my main point was that it is not that easy to prove that self-defense with guns has a positive utility value because a lot (most of the time it would seem to me) of times it seems like it has a negative value in the big picture, the big question being if the positive examples outweight the negative ones,"
Yes, that would be a tar pit of an argument, mainly because of scale necessary to account for all the effects and considerations. I would say that it's impossible to avoid making moral arguments one way or another, so pre-existing moral stance will necessarily determine the outcome.
As an example:
" dependent of your own moral system (do you think grave injury to be worse than death,"
As previously explained: sometimes yes.

"do you believe every life to be of the same value...). "
No, on economic, practical and moral scale.
So, two of those considerations necessarily inform my view of the problem.

I could write a lot about game theory and how evolution (even before homo sapiens was a thing) dealt with it biologically and socially, but short version is that human rationality is bounded by both cognitive imperfection and psychological traits that vary throughout the population. That means that there will be no uniform moral reasoning, and most practical solutions rely on that reasoning implicitly.
If we arrived to a point where our moral stances are different, there will be nowhere else to go.