After a school shooter kills a bunch of kids, people intent on diverting attention from gun control have a tendency to focus on enhancing physical security at schools, by way of armed guards, armored access points, etc. It can seem heartless to focus on the cost of those things when kids are dying.... but that's what I'm going to do.
First, installing one armed guard at a school is unlikely to do anything. Someone intent on mass slaughter could simply walk up to the guard and gun him down before he even had his gun unholstered. It would just be another body on the pile. If you're going to make any real difference, you'd need at least two on duty, with a multiple-checkpoint setup, such that if you attack the guard at the first checkpoint, the second checkpoint gets locked down by a second guard (probably manning a security camera feed some distance away) and the attacker can't get in. That's the kind of setup you see at secure facilities.
So, what would it cost, per school, to have a setup like that? Assuming you're not comfortable with untrained minimum-wage goons, let's say $50,000 per guard per year, minimum, fully loaded (counting benefits). And let's say 2.5 guards per school (some extra to cover absences). There are 130,930 K-12 schools in the US. So, about $16.4 billion per year, plus however much you need for those security cameras, remote locking doors, and other retrofits. We'll conservatively estimate those are fairly cheap and the whole thing can cost just $20 billion per year.
OK. And how many lives will that save? Let's give it every benefit of the doubt and imagine it's perfectly effective -- that these guards manage to completely stop school shootings, while never accidentally shooting the wrong person. So, let's say about 36 lives saved per year, average:
https://www.cnn.com/interactive/2019/07/us/ten-years-of-school-shootings-trnd/
OK, that's a cost-per-life-saved of about $556 million per life.
Now, you might be tempted to say a life is infinitely valuable, so that's well worth it. But, as a practical matter, that's just not how budgeting is done in other contexts.
For example, in the Bush years, if a proposed EPA rule cost over $3.7 million per anticipated life saved (e.g., efforts to reduce arsenic in drinking water), it was considered too expensive to be worth it. With Clinton, they were more liberal about it and put the threshold at $6.1 million:
https://www.americanprogress.org/ar...-costs-and-benefits-of-cost-benefit-analysis/
Obviously, even the higher of those numbers is VASTLY below the $556 million level we're talking about here.
Some studies suggest that any regulation that costs more than, say, $15 million per life saved will actually hurt income levels enough that such a regulation will indirectly cost more lives than it will save:
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1465-7295.1999.tb01450.x
https://www.semanticscholar.org/pap...rall/d2010e118e2edcd1e2e0e99227af6047b66355e6
For example, people whose take-home pay is lower thanks to funding all this extra school security may skimp on vehicle maintenance or healthcare, and that will end up costing more lives than you're saving.
Some studies have put the number even lower, around $12 million:
https://law.vanderbilt.edu/files/archive/215_Value_of_Life_Legal_Contexts.pdf
The gap we're talking about is huge, between that hypothetical $12M-$15M/life point of being counter-productive, and the $556M/life we're talking about here.
Even if you think you can get all that benefit with only half as many guards with half the other security spending, we're still talking almost twenty times the cost-per-life-saved that studies say you can have before the cost is actually driving deaths UP indirectly.
Even if you're in the camp where money should be no object when it comes to saving the lives of kids, then spend those same billions on bigger subsidies for childhood healthcare, for instance, or regulations to make vehicles safer, or spending to make roads safer (more streetlights and guardrails, better signage), or enhanced childhood nutrition, etc.; you'd save many, many more lives of children:
https://books.google.com/books?id=L...ge&q="cost per life saved" guardrails&f=false
So, the approach of trying to prevent school shootings by way of more physical security is almost certainly a loser. Any spending in that area is likely to have a cost-per-life-saved so huge that we'd do better spending the same money any number of other places.... or not spending it at all.
