The Volokh Conspiracy

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Covid-19, the Evil Genius, and How to Think about Societal Risks

How much risk of loss of life people are willing to accept likely depends on how one asks the question


When I was in law school, my Torts professor was Dean (now Judge) Guido Calabresi, affectionately known to everyone as Guido. Each year, Guido gave his class a hypothetical that ran something like this: Imagine an Evil Genius comes to you before the automobile is invented and offers you all the advantages of the automobile, in exchange for killing 50,000 people a year (the rate of deaths in car accidents at the time in the U.S.). If you turn down the offer, society will organize itself in a way that's not automobile dependent, and, perhaps counter-intuitively, Guido asked us to assume that the 50K lives were not being made up by hypothetical lives saved by the existence of cars. Basically, the problem asks whether one would be willing to kill off 50K lives a year in exchange for the conveniences and pleasures of the automobile.

I objected to the hypo on the grounds that automobiles do in fact save as well as cost lives, but something else bothered me about the problem, and I couldn't quite put my finger on it until I thought about it again many years later.

I realized that what bothered me about the hypo was that it assumed that the right way to look at the problem was to assume that one is a central planner, and gets to decide for everyone whether to kill off 50K people. When you put it that way, it's hard to justify killing 50K people for mere pleasure and convenience.

But there is another way to look at it, a more methodologically individualistic way. In a country of 300 million people, 50 thousand deaths a year means you have, on average, a one in six thousand chance of dying each year in a car accident. So an alternative way of approaching the problem is to ask, "would most people be willing to accept an additional one in six thousand risk of dying each year in exchange for the conveniences and pleasures of the automobile." That might give you a different answer than the Evil Genius hypo.

But wait, there's more. The risk of dying in a car accident is very much dependent on one's own behavior. Driving while intoxicated, speeding, driving in ice storms, driving more miles a year than average, driving a less-safe car, and so on, can dramatically increases one's risk of dying, while the opposite behaviors can dramatically decrease one's risk. So the question might instead be, "Would the average person, knowing that he can dramatically increase or decrease his own risk depending on his own behaviors, be willing to accept an average 1 in 6000 chance of dying in exchange for…." Framing it this way allows the risk-averse to take into account their own risk-averse behaviors, and the non-risk-averse to accept a greater risk.

Turning to Covid-19, let's say a particular public health intervention is predicted to save 100K lives. If you ask someone if they would be willing to sacrifice 100K people to avoid this intervention, people will be inclined to say no, "I would never put a price tag on human life, much less 100K human lives." But let's say you ask the question differently: "Would you be willing to accept a one in three thousand chance of dying this year to avoid this public health intervention?" or "Would you be willing to accept an average of a 3% or so increase in your risk of dying this year to avoid this public health intervention" (given that the background annual death rate in the U.S. approaches 3 million)?

Once you ask the question in one of the latter two ways, then instead of focuses on the raw number of deaths, we can focus on the tradeoffs, and of course the answer will vary both by an individual's own risk of being one of the victims (the ill and elderly have much greater risk), and the effect that the intervention will have on their own lives. Individualized behavior is going to make less difference than in the automobile example, but the principle of looking at individual or individualized risk, rather than raw numbers of victims, is the same.

So let's take a simplistic, intentionally skewed example: the government wishes to undertake an intervention that the best economists predict will lead to a permanent reduction in overall wealth of 10%, with vast unequal distribution of burdens, say shutting down all businesses for six months. The same person who would never acknowledge being willing to consign 100K people to death for "economic" reasons may very well be willing to accept, both personally and for the collective, a one in three thousand chance of dying (or a 3% average increase in the chance of dying) this year, or even a much higher risk, so that both society as a whole doesn't become significantly and permanently poorer, and some people (e.g., small business owners) don't lose everything.

I can't, as a philosophical matter, tell you that looking at average individual risk or individualized risk vs. average individual cost or individualized cost is a sounder way of looking at the problem then the more collectivist, central-planner-type approach that Guido assumed. But it's certainly an *alternative* way of looking at social trade-offs, and one that appeals more to my own mindset. And to my understanding, the more collectivist approach dominates public health education, and will therefore likely dominate medical advice about Covid-19.