When Do Weapons Make Things Worse?
Concrete Evidence (May 25, 2026)
Is an armed society a polite society, or just a violent one? Americans have been debating the question forever.
A fascinating new working paper from authors at Santa Clara University and Columbia says it depends—on both the weapons in question and the preexisting traits of the society they’re introduced to.
The study, which has sparked interest over at Marginal Revolution, is a bit of a departure from the work we usually discuss here. The authors make their case by outlining a theoretical model and applying it to a few case studies, as opposed to running fancy statistics on a big dataset. But their way of approaching the topic deserves further exploration and study.
The authors draw attention to three features of weapons: their lethality, which deters aggression; their “offensive advantage,” meaning their ability to end the conflict before the opponent even gets a chance to respond, which reduces deterrence; and their “multi-target capacity,” meaning their ability to mitigate an opponent’s numerical advantage in group conflict.
These features can have different effects in different environments, depending on, for instance, what people have to lose and how frequently conflicts arise—and the effects can compound over time, the authors theorize. Here’s how they describe these dynamics:
When baseline prosperity is high and weapons allow credible retaliation … a marginal increase in lethality deters a large share of conflicts. The hazard rate falls, agents invest more, the value of life rises, and the threshold for violence rises further. We call this a virtuous cycle. When baseline prosperity is low or offensive advantage is high, the same increase in lethality fails to deter enough violence to offset the higher death toll from the fights that still occur. The hazard rate rises, agents divest from the future, the value of life falls, and violence becomes easier to trigger. We call this a vicious cycle—a desperation trap that deadlier weapons deepen.
After laying out their model in considerable detail, the authors argue it does a good job of explaining the dynamics of four different historical episodes.
In medieval Iceland (around the turn of the first millennium), for “over three centuries, armed households in Iceland sustained social order without a sovereign,” aided by assemblies that handled disagreements, a blood-feud system that enabled retaliation (and thus deterrence), sword-and-shield weaponry that favored defense, and a farming society where people had property to lose.
In Tokugawa Japan, covering most of the 17th through 19th centuries, firearms were common but society was rapidly becoming more prosperous. The country enjoyed peace internally, until rural conditions weakened and then the U.S. Navy showed up.
Meanwhile, Europeans often traded guns for slaves along the coast of Africa, and the weapons were useful for capturing more slaves. Unsurprisingly, this was not a stabilizing force.
Lastly, guns traded to Native Americans had similar effects: “Mounted Comanche raiding parties armed with firearms could strike dispersed Mexican settlements at distances that minimized retaliation,” the authors write, “and the resulting predatory equilibrium grew over a century, with the Comanche population tripling and their territorial reach extending across the southern plains.”
It’s fair, I think, to knock the paper as an academic exercise in theory, anecdote, and inevitably debatable historical narratives. It’s certainly not hard proof of very much, beyond the obvious fact that different weapon technologies deployed in different environments can produce different results. It’s hardly surprising that guns can enable bloodshed in situations already prone to it, that they can empower early adopters over unarmed opponents, or that they can have little impact on violence, and perhaps some benefits to stability, in places where people have less need to kill each other.
Yet at minimum, the paper offers a framework to consider as we study these matters going forward. Even within a given society, different demographic groups will suffer different consequences from the same weapons policies. If we’re going to have weapons around—and we definitely are, at least here in America—it’s worth knowing in which conditions they tend to make things worse.
From the Manhattan Institute
Alex J. Adams explains how federal agencies should reduce regulatory “dark matter”—the rules that exist not in formal regulations, but in informal guidance documents.
Other Work of Note
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An entire journal issue dedicated to boys’ educational struggles.
Has immigration employment improved employment for natives?
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How Dodd-Frank changed acquisitions.
Null results for GLP-1s’ effects on “mental health, self-rated health, employment, and marriage.”
New findings on the geography of social mobility, with interesting differences based on whether one measures by income versus wealth. And is there a “tradeoff between those places that most effectively produce human capital in childhood and the local labor markets that do so in adulthood”?
Trends in Los Angeles homelessness. See also Chris Rufo and Kenneth Schrupp’s survey showing more than half of L.A.’s homeless aren’t from the city.
"their lethality, which deters aggression" - this is only true if there's a credible threat that law abiding citizens will use lethal retaliatory force when provoked. Outside of the handful of stand-your-ground states this is likely an unfounded assumption, since shooting someone trying to mug you will still get you charged with murder.