A few days ago, Megan McArdle wrote an op-ed in Bloomberg View warning readers to “Beware of Blaming Government for London Tower Fire.” True, the government chose to install unsafe cladding on the outside of the building instead of a fire-resistant option to save £5,000, ignored residents’ pleas for additional staircases or a sprinkler system, and literally gave the money back to the wealthiest taxpayers, i.e., people who were unlikely to live in a council flat to begin with. But, as McCardle wisely reminded us, “There’s always a trade-off.” Maybe installing fire safety measures in public housing would save a few lives, but it’s also possible that there would be unintended consequences. For instance, she suggests that people might have to move farther from their workplaces to afford pricier fire-safe buildings, leading to their nearly-as-fiery deaths in car accidents on their longer commutes—possibly killing even more people than died in Grenfell Tower! (We’ll never be sure, of course, because the police don’t think they’ll be able to identify all the bodies or give an accurate fatality count.) It really makes you think.

McArdle’s clear-eyed moral and economic analysis (basilisk-eyed, even) came to mind today as I was walking through my neighborhood and saw you spontaneously combust on the other side of the street. On first glance, my reaction—acting as if nothing out of the ordinary was happening as you screamed and flailed your arms and batted hopelessly at the spreading flames—might seem callous to the point of being monstrously evil. But is it really that simple? McArdle suggests it is not.

True, you might have a better chance of surviving if I were to cross the street and make some effort to put out the fire, even if it were by doing something so trivial as spitting on you. But instead, I’m just walking by on the opposite sidewalk, deliberately paying no attention and continuing on my merry way. This does not play well for me.

But before you start hanging me in effigy, there are a couple of things we should consider. The first is that, even if I crossed the street and successfully put out the flames, I might not be fast enough to save your life. Fires are not put out like instant coffee (though they might be put out by instant coffee, if only you had some, ha ha ha!). What’s more, this is a pretty wide street, and it might take me a long time to cross it. From what I can see from this distance (pretty far now, because I’ve continued walking while you’ve continued burning), being on fire has already caused an inflammatory response that is leading to an enormous loss of blood and fluids, so spitting on you to put out the flames might be a case of throwing good bodily fluids after bad ones. And that’s if I put the flames out to begin with: All the political will in the world cannot conjure up enough spittle to save you once your clothing starts wicking fat into the heat like a candle.

This, however, is only a quibble; even if you cannot be saved, there are surely other people who would benefit from a societal commitment to crossing the street to spit on people who are on fire. Must we wait for these deaths before we can say this was a bad calculation?

Well, no. But we should wait until we can establish that it was actually a bad calculation.

It may sound heartless to describe life-saving measures as a calculation. But the fact is that I make these sorts of calculations every day, about myself and others, and especially you, personally. I just don’t like to admit that I’m doing it, because it sounds heartless. So I find it reassuring to assume that everyone else also makes those calculations.

Consider the amount of water you drink in a day. I’m sure you all stay very well-hydrated! Nonetheless, when you are spitting to put out a fire, the margin of error for avoiding an uncomfortably dry mouth is pretty small. To spit on even something as trivial as a burning match is to accept a small risk of feeling thirsty in an hour or so. To try to help you as your hair starts catching is to accept a much higher risk of feeling thirsty, even parched. It’s a calculation: risk versus reward.

I have made that choice, and so I assume all Americans have too: nope, not worth it. I (and I assume, we) are manifestly not willing to exchange “cottonmouth” for lower fire fatalities. Nor, as far as I am aware—and I will do my best to never become more aware—is anyone, anywhere else. (Pro tip: If you’re on fire, or at a higher risk of being on fire due to your economic status, you are in no position to assess the costs and benefits and your opinion should be discounted in favor of objective observers like me.)

When the cost is as personal, as glaring and obvious, as having a slightly dry mouth until you can walk to the corner store to buy a bottle of water, we can see that not all safety trade-offs are worth it. However, when the cost seems to be borne by someone else, we suddenly become safety absolutists: No price is too great to pay.

Unfortunately, “other people’s spit” has a way of ultimately coming out of our own mouths. If we expect we might be asked to spit on a person to prevent him or her from burning to death, then we will drink more water, and the cost of bottled water will rise. People will be forced to drink tap water, perhaps tap water contaminated with lead as the result of a similar cost-benefit analysis made by people who only drink bottled water. Some of the people drinking that lead-laced water, in fact, may be children, who will grow up violent as a result of lead exposure, and then go on to become serial killers. We don’t see these costs in the same way we see you, literally on fire on the other side of the street at this exact moment; we will never know the name of the guy who builds a gigantic murder palace in downtown Chicago 20 years from now because he had to drink lead-laced tap water as a kid because there was a societal expectation to try to save peoples’ lives when they were on fire because I crossed the street to spit on you while you were burning. But that is a distinction for public opinion, not for good policymaking. Good regulations would take into account the very real risk that by inconveniencing myself in even the tiniest way to save your life, I would be unleashing a generation of lead-maddened killers to prey on children yet unborn.

Back to the case at hand: Maybe I should cross the street to spit on you while you’re on fire. It’s completely possible I’m making the wrong call. But I’m thinking about the question in the right way—taking seriously the fact that putting out the flames engulfing your face and hair comes at a cost, which might exceed its benefit. Benefit to me, of course, not to you: You’re on fire! But such calculations have to be made, and taken to absurd lengths, so no one feels like there’s any blame to be had here, no matter how horrified the tut-tutting after the fact. I personally really love making these calculations, for some reason, and the more horrified the tut-tutting, the better. As long as I can make fire safety seem like a complicated debate instead of a moral choice a toddler could get right, I can make sure no one takes any action, and that’s worth more—in monetary terms, because what other way is there to understand the world?—than your petty ideas of “good” and “evil.”

And I am certainly right about one thing: When it comes to many regulations, it is best to leave such calculations of benefit and cost to the market, rather than the government. You can make your own assessment of the price you’re willing to pay to have a chance of surviving this fire, rather than substituting the judgment of some politician or bureaucrat, who will not receive the benefit or pay the cost. I mean, they’re not on fire. How much would you pay me to cross the street and try to save you? Seriously, how much have you got?

It’s possible that by declining to cross the street and make any effort to save you from burning to death, I have prevented untold millions of people from being murdered at the hands of serial killers, which makes me a hero, if you think about it. It’s also possible that my efforts would not have saved your life, even if I’d immediately run across the street instead of blathering on about cost-benefit analysis. Regardless, I certainly can’t save you now, since your arms are already twisting into the characteristic pugilistic posture of burned bodies as your desiccated muscles shrink and contract. It almost looks like you want to punch the people who did this to you, then move onto anyone who reassured those same people that no one was to blame and nothing could be done. Or at least it looks like you’d do that, if you hadn’t died in a fire.