Last year, Bryan Caplan wrote about what he called The Unbearable Arbitrariness Of Deploring:

Let’s start with the latest scandal. People all over the country – indeed, the world – have recently discovered that many celebrities are habitual sexual harassers. Each new expose leads to public outrage and professional ostracism. Why does this confuse me? Because many celebrities do many comparably bad things other than sexual harassment, and virtually no one cares. Suppose, for example, that a major celebrity is extremely emotionally abusive to all his subordinates. He screams at them all the time. He calls them the cruelest names he can devise. He habitually makes impossible demands. He threatens to fire them out of sheer sadistic pleasure. But the abuse is never sexual (or ethnic); the celebrity limits himself to attacking subordinates’ intelligence, character, pride, and hope for the future. I daresay the average employee would far prefer to work for a boss who occasionally pressured them for a date. But if the tabloids ran a negative profile on the Asexual Boss from Hell, the public wouldn’t get very mad and Hollywood almost certainly wouldn’t ostracize the offender […] Or to take a far more gruesome case: When the Syrian government last used poison gas, killing roughly a hundred people, the U.S. angrily deployed retaliatory bombers, to bipartisan acclaim. But when the Syrian government murdered vastly more with conventional weapons, the U.S. government and its citizenry barely peeped. The unbearable arbitrariness of deploring! In the past, I’ve made similar observations about Jim Crow versus immigration laws, and My Lai versus Hiroshima. In each case, I can understand why people would have strong negative feelings about both evils. I can understand why people would have strong negative feelings about neither. I can understand why people would have strong negative feelings about the greater evil, but not the lesser evil. But I can’t understand why people would have strong negative feelings about the lesser evil, but care little about the greater evil. Or why they would have strong negative feelings about one evil, but yawn in the face of a comparable evil.

He concludes people are just biased by dramatic stories and like jumping on bandwagons. Everyone else is getting upset about the chemical weapon attack, and people are sheep, so they join in.

I have a different theory: people get upset over the violation of already-settled bright-line norms, because this is the correct action if you want to use limited enforcement resources efficiently.

Imagine a town with ten police officers, who can each solve one crime per day. Left to their own devices, the town’s criminals would commit thirty muggings and thirty burglaries per day (for the purposes of this hypothetical, both crimes are equally bad). They also require different skills; burglars can’t become muggers or vice versa without a lot of retraining. Criminals will commit their crime only if the odds are against them getting caught – but since there are 60 crimes a day and the police can only solve ten, the odds are in their favor.

Now imagine that the police get extra resources for a month, and they use them to crack down on mugging. For a month, every mugging in town gets solved instantly. Muggers realize this is going to happen and give up.

At the end of the month, the police lose their extra resources. But the police chief publicly commits that from now on, he’s going to prioritize solving muggings over solving burglaries, even if the burglaries are equally bad or worse. He’ll put an absurd amount of effort into solving even the smallest mugging; this is the hill he’s going to die on.

Suppose you’re a mugger, deciding whether or not to commit the first new mugging in town. If you’re the first guy to violate the no-mugging taboo, every police officer in town is going to be on your case; you’re nearly certain to get caught. You give up and do honest work. Every other mugger in town faces the same choice and makes the same decision. In theory a well-coordinated group of muggers could all start mugging on the same day and break the system, but muggers aren’t really that well-coordinated.

The police chief’s public commitment solves mugging without devoting a single officer’s time to the problem, allowing all officers to concentrate on burglaries. A worst-crime-first enforcement regime has 60 crimes per day and solves 10; a mugging-first regime has 30 crimes per day and solves 10.

But this only works if the police chief keeps his commitment. If someone tests the limits and commits a mugging, the police need to crack down with what looks like a disproportionate amount of effort – the more disproportionate, the better. Fail, and muggers realize the commitment was fake, and then you’re back to having 60 crimes a day.

This looks to me like what’s happening with chemical weapons. The relevant difference between chemical weapons and conventional weapons is that the international community made a credible commitment to punish chemical weapons use, and so far it’s mostly worked. People with chemical weapons expect to be punished for using them, so they rarely get used. If there are some forms of atrocity that are easier with chemical weapons than with conventional ones – ie a dictator with a limited arms budget can kill more people with a choice between chemical and conventional weapons than they can when restricted to conventional weapons alone – then the taboo against chemical weapons saves lives. And so when a dictator tests the limits by trying a chemical weapon, it’s worth responding to that more forcefully than if they used conventional weapons to commit the same massacre. You’re not just preventing the one attack, you’re also acting to enforce the taboo.

The sexual harassment situation seems like the same dynamic. We can’t credibly demand our elites are never jerks to their subordinates – jerkishness is too vague a concept, there’s too much of it around, and it’s just not really an enforceable norm. But we have sort of credibly demanded our elites don’t sexually harass their subordinates, and it seems like we might be getting enough of a coalition together to enforce this in a lot of cases. If we can solidify this into an actual social norm, such that the average elite expects to be punished for sexual harassment, then elites will stop sexually harassing their subordinates and we won’t have to keep calling the whole coalition together all the time to enforce the punishment. A fixed amount of public outrage per news cycle is the same kind of “limited enforcement resource” as only having ten police officers; commit to using it to disproportionately enforce existing taboos, and you’ll have more of it left over later on.

This is my long-winded answer to a question several people asked on the last links post – why should we prioritize responding to China’s mass incarceration of the Uighurs? Aren’t there other equally bad things going on elsewhere in the world, like malaria?

Yes. But I had optimistically thought we had mostly established a strong norm around “don’t put minorities in concentration camps”. Resources devoted to enforcing that norm won’t just solve the immediate problem in China, they’ll also help maintain a credible taboo against this kind of thing so it’s less likely to happen the next time.