Data and code from: Bivalent impact of social networks on overarming: Insights on the alignment between social and individual interests

Drawing on evolutionary game theory, we present a stylized model of gun
acquisition for individuals in a society where all have the right to bear
arms. In our dynamic model, pairwise confrontations with attendant payoffs
take place between individuals who are either armed or unarmed. Individual
payoffs depend on the probability of confrontation, the choice to arm, and
the choices of others. We show that the likelihood of confrontation
affects the optimal societal arming rate and the arming rate that occurs
in equilibrium. The latter quickly surpasses the former as the probability
of confrontation increases, a phenomenon we call overarming. This reflects
a misalignment of individual and societal interests. We further show that
spatial structures can exacerbate overarming, especially when individuals
perceive a deteriorating social environment. Our modeling results
highlight the importance of understanding how fundamental behavioral
dynamics and network heterogeneity influence individual decisions to
acquire firearms.