It is a tragedy to Charlie—his life was cut prematurely short. And it is a tragic signal that the wrong words spoken, even in a liberal democracy, can get you killed. As an academic and public intellectual, I find that chilling.

It is also, unsettlingly, a case study in how democratic incentives can corrode political life. For all the shock and horror surrounding the killing, its logic is not entirely mysterious. The tools of political economy and philosophy, especially concepts like rational irrationality and theories like costly signaling theory, can aid our understanding why political violence sometimes emerges from within democracy itself.

Economists and philosophers have long puzzled over a simple question: Why do citizens participate in politics when their individual actions are almost certain not to matter? Casting a single vote, attending a protest, or writing a letter to a representative rarely changes the outcome. The probability that your ballot tips a national election is about one in sixty million. That's roughly the same chance as winning a state lottery jackpot twice. So, in light of this, it would seem irrational for anyone to spend time or resources on politics at all. Yet people do and they often do so passionately.

A popular account developed by the economist Bryan Caplan holds that citizens are "rationally irrational." It is thus practically rational for individuals to indulge epistemic biases and partisan fantasies because the cost of doing so is virtually zero. If my single vote or tweet or protest sign won't decide the outcome, why not use politics to express my tribal identity?

On this account, political ignorance and bias are not the products of stupidity, but instead are the product of perverse incentives. It is rational for individuals to remain ignorant about complex policy details while indulging in expressive forms of political identity. The personal cost of error is negligible, and the tribal payoff can be large.

This same logic extends into darker domains. Assassination almost never achieves the ends its perpetrators imagine. Institutions adapt, successors step in, movements endure. Killing Charlie Kirk will not dissolve the conservative youth movement he helped energize, nor will it cure America's polarization. Yet the assassin's calculus often looks different. Violence can be treated as a kind of expression—an act that signals loyalty, registers rage, or manufactures instant notoriety. Within the distorted incentive structures of democratic politics, such violence may appear subjectively rational: a way to demonstrate tribal allegiance. However, judged from the outside, it remains objectively irrational, producing social and political harms that far outweigh whatever fleeting sense of meaning or recognition the killer sought.