How dangerous are mountain lions? The data tell an interesting story. Since 1980, there have been only 13 attacks in all of California (where David and Charley live) and three people have died as a result. Compare this with attacks by dogs. Each year in California, about 100,000 dog attacks cause their victims to get medical attention. This means that California residents are approximately 180,000 times as likely to be seriously attacked by a dog as by a mountain lion. But to really compare dogs and mountain lions, we need to check our base, because there are a lot more dogs than mountain lions. With so many more dogs running around, a reasonable person would expect more dog attacks. With about 8 million dogs and 5,000 mountain lions in California, we see that there are approximately 1,500 dogs for each mountain lion. Once we check our base and correct for the numbers of dogs and mountain lions, we see that dogs are still more dangerous, and in fact, the risk of serious attack from an individual dog is about 120 times that of the risk from an individual mountain lion. Mountain lions present a daunting and ferocious image, but with so few attacks, they must have very little interest in attacking people.
This quote is from David R. Henderson and Charles L. Hooper, Making Great Decisions in Business and Life, Chicago Park Press, 2006.
The picture above is of me at the entrance to Stanford University yesterday. It reminded me of maps I saw of Germany divided into 4 zones after World War II. My friend and co-author Charley Hooper and I walked on the campus and notice a whole lot of 20-somethings walking around wearing masks even though they were typically walking alone and were not closer than 30 feet to anyone else.
They seem to fear COVID-19 the way some people fear mountain lions. My guess is that it’s a mixture of their fear and the fear of the administrators of Stanford, who seem to have taken an extremely anti-intellectual approach to the issue.
Either way, the risk to the young is extremely low. Here are data from the Centers for Disease Control as of November 12, 2020. They are for the number of deaths between February 1, 2020 and November 7, 2020. (The CDC notes that there is a lag because death counts are somewhat delayed.)
The number of Americans of age 15 to 24 who have died of COVID-19 is 410.
The number of Americans of age 15 to 24 who have died of all causes is 26,662.
Watch out for dogs, not mountain lions.
If you’re young, watch out for deaths from other causes, not COVID-19.
Postscript: What brought us to Palo Alto is my 70th birthday, which I celebrate on Saturday. Because it’s impractical right now to do what Governor Newsom did but tells the rest of us not to do, I’m not having a 70th birthday party. Instead, I’m seeing individual friends for outdoor lunches and conversation. Charley, Jay Bhattacharya, and I had a wonderful almost 3-hour outdoor lunch and conversation.
READER COMMENTS
Anonymous
Nov 18 2020 at 2:56pm
I’ve noticed some people have a strange compulsion to jump to other people being “afraid” because they wear masks or whatever. Maybe people just find it more convenient to wear the mask around so they don’t have to worry about taking it on and off as they go in and out of buildings or greet people/groups of people, and don’t find it overly uncomfortable?
David Henderson
Nov 18 2020 at 3:03pm
I don’t think it’s that strange.
If they’re doing it for the reason you suggest, then yes, you have a point. I would bet dollars to doughnuts, though, that over 40% of them are afraid.
Laron
Nov 18 2020 at 3:38pm
If the campus is anything like here in Hawaii, the habit could be due to guilt also. The state and counties are running relentless campaigns to push mask use with explicit and just-slightly-implicit messages that only stupid/evil people don’t wear a mask at all times and not doing so will kill everyone’s kupuna (grandparents). When cases increase, the fault lies with those people rather than failures in state/county leadership or even exogenous/uncontrollable factors.
Even for someone like me who supports mask wearing, the way it’s being marketed is essentially guilt-tripping the population into complying. Particularly when the state has north of 80% compliance already and a new statewide mandate, I dunno but it just doesn’t sit right.
IVV
Nov 18 2020 at 4:14pm
Afraid of dying, afraid of getting sick, afraid of becoming a spreader to potentially more vulnerable people, or afraid of long-term complications?
David Henderson
Nov 18 2020 at 4:27pm
Probably a combination.
IVV
Nov 19 2020 at 5:26pm
If it’s any of the above, then the chance is quite a bit higher than only the chance of dying.
Dylan
Nov 18 2020 at 4:45pm
Well, here in NYC, I can tell you that I see a lot more people wearing masks outdoors when distant from people now than I did a few weeks ago. Could it be the stories on the news about cases rising dramatically, quite possibly, but I’d bet it also has something to do with the fact that it is suddenly cold and a lot more comfortable to have something over your nose than it was when it was 70 (which is was last week)
To Laron’s point, there’s also the perception issue. I tend to think of it as more of a political statement than guilt, although I’m sure both are involved. Wearing a mask (and wearing it correctly) is a very outward sign showing that you are doing your part. I’ve had a number of smaller gatherings with younger people over the summer and early fall, and masks quickly came off when they were in a more private setting, even if the risk was higher than just walking down the street.
Mark Brophy
Nov 19 2020 at 10:02pm
I hired a 25 year old TaskRabbit to help me move furniture. He wore a mask because he was somewhat afraid but didn’t mind that I didn’t wear a mask. I wish the Governor of Colorado was as tolerant as him.
Kevin Dick
Nov 18 2020 at 4:52pm
Happy Birthday! Next time you come to Palo Alto, look me up! Jay and I are actually friends. Weird to think you know each other as you are in completely different mental compartments for me.
David Henderson
Nov 19 2020 at 11:20am
Thanks, Kevin.
Alan Goldhammer
Nov 18 2020 at 5:43pm
Happy Birthday.
I’ll be a sourpuss and note that the critical issue has always been hospital capacity. A number of Midwest Governors are now putting mask requirements in place and limiting gatherings because of the explosion of COVID-19 cases. I suspect the great ‘herd immunity’ experiment is taking place in some communities right now and I hope the cost is not too high. For those who think COVID-19 is like a little flu, this Swiss paper on hospitalizations will dispel that.
While mortality in young people is low, they can still be viral carriers and infect others. This is what it was always about.
David Henderson
Nov 18 2020 at 6:04pm
First, thanks on the birthday greeting.
Second, it’s hard to see how anyone, young or old, can pick up the virus while walking at least 20 feet from anyone else. That Stanford campus was almost deserted.
Rob Rawlings
Nov 18 2020 at 10:28pm
‘Watch out for dogs, not mountain lions.’
I’m walking down the street and see a dog. I remember this post and think “there are 8 million dogs and 100,000 dog attacks that lead to hospitalizations each year (and the post doesn’t say but I assume a very small % lead to death).
I’m walking down the street and I see a mountain lion. I remember this post and think “there are 5,000 mountain lions and since 1980 13 people have been attacked and 3 have died).
Am I wrong to be more scared of my confrontation with the lion rather than the dog ?
(I know the post is about whether one should in general be watching out for dogs, not mountain lions, but I’m curious where the logic in my comments is wrong)
Rob Rawlings
Nov 18 2020 at 11:17pm
Oops, I see you crunch the numbers and show that the risk of serious attack from an individual dog is about 120 times that of the risk from an individual mountain lion.
You don’t reference the chance of death from dog-attack v lion-attack but I would guess there may be enough dog-attack-related deaths to lead to the same conclusions?
Mark Brophy
Nov 19 2020 at 10:04pm
You’re very fortunate to see a mountain lion, they usually run when they see humans. If they decide to attack, it will be an ambush.
Mark Bahner
Nov 18 2020 at 11:18pm
How many people have mountain lions for pets? I’m guessing that if as many people had mountain lions for pets as have dogs for pets, there would be a lot more attacks of people by mountain lions than by dogs.
P.S. Which reminds me of books by Jack Douglas, including: “The Neighbors are Scaring My Wolf” and the sequel, “The Neighbors are Scaring My Mountain Lion.”
Jonathan S
Nov 19 2020 at 2:19am
Exactly what I was thinking, even though I agree with David that innumeracy is way too common.
My guess is that the average dog in California has a 12+ hour time window every day to attack a human, if desired. I’d guess that the average mountain lion in California has a 10 minute time window once per week to attack a human.
Also, my guess is that the average human would be able to fend off the average dog with modest effort, whereas the mountain lion kill rate 3 out of 13 (23%) are not favorable odds.
So if the question is restated as: would you rather be in a gladiator battle against a typical dog or a typical mountain lion? I think just about everyone would choose the dog.
Charley Hooper
Nov 19 2020 at 1:00pm
The questions of which animal would be more dangerous to fight and what would happen if we had mountain lions as pets are interesting, but those questions address alternative situations. We don’t keep big cats as pets and we don’t fight them in contests.
The point is that in our lives, as we live them today, we are more likely to be harmed by an individual dog than by an individual mountain lion.
What we should focus on, however, is not that dogs are especially dangerous, but that mountain lions have close to zero interest in attacking humans. The reality is far different than the perception.
Mark Bahner
Nov 21 2020 at 1:55am
Yes, it’s a lot easier for them to pick off pets!
I just don’t agree that “mountain lions have close to zero interest in attacking humans” is a valid conclusion from the data. There are very few mountain lions, especially near humans. Mountain lions hunt at night. Humans are generally at home at night. Wise humans don’t move alone–and possibly more importantly, carry some sort of protection–in mountain lion territory.
In a similar matter, there are very few Komodo dragon attacks:
That’s a good boyyy, that’s a good boyyyy!
But that doesn’t mean that Komodo dragons don’t have any interest! It means that there aren’t that many Komodo dragons, and humans don’t try to scratch the ears of Komodo dragons.
Just this very day, my parents and I were at Bruster’s eating ice cream in our car, and watching two women with some sort of pit bull mix sitting at the outdoor table. The pit bull mix was very skittish, particularly when one women would reach from behind to pet its head (it would jerk its head around, with fear in its eyes). When some other people came walking by, it was very excited and wagging its tail. My guess was that the dog might have been abused by previous (expletive deleted) owners.
If I had approached the dog, it would have been very slowly and I’d be careful to stay in front. But I could see how the dog might easily bite a stranger, if the stranger quickly approached from behind, or came up from the front all excited, and they quickly reached around behind.
But if I encountered a mountain lion, I wouldn’t approach. I wouldn’t want to experiment with “careful” ways to approach a mountain lion!
Jens
Nov 19 2020 at 5:58am
Aside from the time window, the step from the probability of a fatal Mountain Lion attack (apparently 3/13) to the risk of a severe attack by a dog is also unclear.
I doubt 3 out of 13 dog bite victims die, even if only those who are undergoing medical treatment are included.
Dogs generally do not hunt people, they are fearful or show territorial behavior. I have been bitten by dogs twice and it hasn’t even bled properly.
Shane L
Nov 19 2020 at 4:43am
Young people should avoid getting Covid-19 so that they don’t pass it on to more vulnerable people. Young people taking precautions are probably not scared, they’re good people putting others’ safety before their own. They are the 21st century version of volunteers to the military, to hospitals or Air Raid Precautions in World War II – good on them.
Young people who party and socialise in blissful indifference are not brave, they are selfishly passing on a disease that will affect few of them, but may kill their grandparents.
Jens
Nov 19 2020 at 6:48am
That’s another good point. Bite wounds are generally not contagious in themselves. There may be exceptions in which infectious diseases are transmitted that way, but then the exceptions are also interesting.
This whole article is actually a good example of how messed up the discussion about Covid-19 is. In fact, hardly anyone claims that it is a zombie apocalypse. That would really worry me.
But what’s the point of stating that i’m safe from the big cat if on the right side of the bars ? There are people who go to the other side with suicidal intent … and that works quite often.
MarkW
Nov 19 2020 at 8:16am
Why can’t youngsters be responsible by avoiding close contact with the oldsters, and the oldsters be responsible by returning the favor? I live near campus in a college town with tens of thousands of resident students, and many did contract Covid this Fall. This did not worry me–we’re simply never in close contact. And the students who did have Covid while here can go home to see their families over Thanksgiving without concern for spreading the disease to loved ones.
Mark Brophy
Nov 19 2020 at 10:14pm
The prevalence of Covid-19 is 15x higher among people under 50 than among people older than 70. Young and old people are staying away from each other. Even among old people, Covid-19 is not dangerous. For those over 60 and not living in a nursing home, the survival rate of those who contract the virus is 98%.
It’s not necessary to frighten and oppress young people to ensure that old people live a safe an interesting life. It’s easy to frighten Stanford students because they’re not very bright and they trust the government too much.
Michael
Nov 20 2020 at 7:04am
This is an absurd claim.
The flu is widely recognized as dangerous for old people – Covid-19 is widely recognized as considerable more dangerous than the flu.
“For those over 60 not living in a ursing home” is cherry-picking data to make your point. The risk of death among those infected with Covid-19 increases with age, so had you said 65 or 70, the risk would be higher. Selecting out people not living in nursing homes is a way to further bias the sample you are looking at, since living in nursing homes is a proxy for vulnerability.
Finally, there is no good evidence to support the claim that the elderly and other at-risk populations can be successfuly isolated. Most studies show that Covid-19 spread into the elderly lags general population spread by a few weeks, because even at reduced rates of interaction, as the community prevalence rises the elderly cannot avoid contact with the infectious.
MarkW
Nov 19 2020 at 6:56am
I take the dog for daily walks in the university arboretum here in Ann Arbor. Virtually all of the 20-something students I see are wearing masks or — this amuses me — quickly pull them up over their face if my dog and I get within 20 yards (and that’s regardless of whether or not our paths are converging). Of course, neither my dog or I are masked, so we do look like a dangerous pair. Perhaps I will now think of us as mountain lions on the prowl.
But these same kids will readily go to outdoor restaurants and sit unmasked at tables spaced out at the minimum legal distance and talk away for a hour or two — which is likely also quite safe, but completely inconsistent with their behavior in the park.
Outdoor masking in open spaces at this point is 99% social signaling. It is something of a relief on weekends to get half an hour out of town to hike on trails where people don’t feel the need to wear masks in the great outdoors for fear of social opprobrium. People out there may even give you a quick smile and exchange a few words as you pass by (at an appropriate distance).
Mark Brophy
Nov 19 2020 at 10:19pm
Young people often pull their masks up on hiking trails when I pass them even though I don’t wear a mask. Most people in Colorado wear a mask on hiking trails and pull it down as soon as they’re not crossing paths with strangers.
Thomas Hutcheson
Nov 19 2020 at 9:50am
I really do not see how a person’s optimal policy for avoiding an attack by mountain lion can have anything to do with the likelihood of an attack by a dog. The same goes for optimal public policy to reduce net disutility from mountain lion attacks. Now if an analyst thinks that mountain lion attack prevention policy is inefficient, costs more than the disutility of the attacks on the margin, then it makes sense to demonstrate that inefficiency and propose an alternative policy with greater net benefits, which might include not trying to prevent mountain lion attacks at all.
The same principles apply in Covid transmission prevention but with an additional twist. Whereas those attacked by mountain lions attacks internalize the benefits of not being attacked and might be presumed to be already taking optimal precautions, those becoming infected by Covid not only suffer individual disutility but cause disutility to others. Nevertheless, the analyst who thinks that the costs of some particular anti-transmission policy has negative net benefits (including the benefits external to the person bearing the costs of the policy) should certainly try to demonstrate this and recommend a policy with non-negative benefits. To truncate the analysis with showing that the net benefits are negative (or worse, only to show that the policy has non-negative costs) risks being taken as an argument for not having any policy to reduce transmission.
drobviousso
Nov 19 2020 at 3:21pm
An excellent point. I want to make a couple comments:
1) In my expert opinion (I am not an expert), masks probably don’t do much to prevent the spread of COVID-19. Air exchange and distancing probably do. And yet, I wear a mask all the time. Because of fear? No. Because other people think it helps prevent the spread, and I’d rather not put them off.
2) Mountain lions are terrifying even if they have never caused a single injury. For one, they sound like “a toddler being fed feet first into a wood chipper” as crusty old Scoutmaster once said, and he was right. They will also stalk humans, and I’ve experienced that once. I’m no wilting flower, but that was probably the most powerful, primal fear, I’ve ever felt in my life.
3) I often play the “Guess the Author” game when I read the Econlib RSS feed, since it doesn’t list the author. David is the easiest to guess, because his posts are so humane. This is the best example of how the human experience can be enhanced, instead of subsumed, by the economic way of thinking. Its a little bit early to say so, but I want to give thanks for each of the authors here who have contributed so much to me over the last, what, decade or so. Even though I have never met any of you in person. I hope its not too late for you to notice this comment.
David Henderson
Nov 19 2020 at 3:37pm
You wrote:
With me it’s the opposite. I’m trying to model a different behavior for them and get them thinking. There have been exceptions. About a month ago, a friend and I were eating outside at our favorite Indian restaurant. We were the only ones there because everyone else was coming for takeout. An elderly lady sat down at a table about 8 feet away. So by the standard rules and understanding, we were not a threat. Nevertheless, we had finished eating and so I said, “Excuse me, madam, if you want me to, I’ll put on my mask.” She answered, “I’m not worried; I’m a Republican.” We laughed and I responded, “I’m not sure which of your admissions took more courage to admit in this town.” We had a fun talk afterwards.
You wrote:
Interesting.
You wrote:
Aw, thanks. That’s the nicest thing I’ve heard all week. I appreciate it.
Philo
Nov 19 2020 at 3:59pm
If you are going in and out of enclosed areas where there are other people, you are supposed to have a mask to wear when you are *in*. Then what to do with the mask when you are *out*? Rather than repeatedly taking it off and putting it on again, and making a place to carry it while it is off, you might as well keep it on even when you are *out*. This might wrongly impress an observer as hyper-caution.
Fred
Nov 19 2020 at 6:20pm
I’m 75 years old and at risk of serious problems with viral infections. I thank the young people who wear masks. It’s hard to find a randomized trial, but many authorities recommend them. I think that masking probably helps a little (no definite evidence available to me), and I’m grateful for even a little help. In the same vein, I wear my seat belt when I drive despite having no serious crashes in sixty years of driving. I feel ok about asking this of young people because it is a minor inconvenience for the wearer not a major sacrifice. I wouldn’t ask anyone to make a major sacrifice for me. I wouldn’t ask anyone to wear a mask to protect me if it hurt David Henderson; I don’t know why he is offended by a voluntary action that has no cost to him.
David Henderson
Nov 19 2020 at 6:34pm
You thank the young people who wear masks when they’re around others, right? But does it really make sense to thank young people who wear masks when they’re not within 20 feet of anyone else?
You infer that I’m offended by a voluntary action that has no cost to me. It would be messed up if I were offended. I’m not. I’m saying that it doesn’t make sense to wear a mask when there’s no one else around.
Diana Weatherby
Nov 20 2020 at 2:06am
It depends. If I were walking from one building to another, why would I take it off. This thing that covers my face is also covered in my germs so when I touch a door handle after taking it off and putting it on after being outside and 20 feet away from someone, I’ve now contaminated a door handle.
Personally, living in a cold area means when I come out of a building I don’t want to take it off until in my car or someplace warm because the moisture makes my face frozen.
People have different reasons for the things they do. Unless you ask, you probably won’t guess correctly.
Fred
Nov 20 2020 at 12:08pm
At the time I made my comment, I was not aware of this publication from 11/18:
https://www.acpjournals.org/doi/10.7326/M20-6817
It is a shred, a weak shred, of evidence.
My inference about your emotional state was wrong. It is wrong to ascribe emotions to other people’s actions. Sorry.
David Henderson
Nov 20 2020 at 3:55pm
Thank you, Fred. I appreciate it.
Diana Weatherby
Nov 20 2020 at 12:08am
Since most masks cannot really protect the person wearing them, I would assume the students are wearing them to slow down the spread, keep their school open, and doing their part to keep hospitals from overflowing.
Perhaps they hate the fact that their friends who are doctors or nurses are overworked and facing the trauma of having to triage patients and shut off life support again and again and that loved ones without covid are unable to get care again for things not related to covid due to health care capacity being strained.
Sometimes it’s not about you, it’s about your community.
David Henderson
Nov 20 2020 at 3:55pm
I get your point and it’s a good one.
It’s hard to see how it applies to this case of young students wandering around an almost deserted campus wearing masks when the closest person is 20 feet away.
Michael
Nov 20 2020 at 7:19am
A couple of things:
I think comparing animal attacks to the spread of an infectious disease is a poor analogy. The most important risk factor for contracting Covid-19 is obvioiusly exposure to others who have it.
I go for a long walk around my neighborhood every day, and I wear a mask while doing so. Along my route, some areas are likely to have me walking past other pedestrians and some area will be mostly empty. I think it would be fine, from a safety perspective, to only put the mask in areas with foot traffic or when near others. But it is just as easy to leave it on. If I’m sitting in my back yard with neighbors, in a distanced way, I don’t wear one – unless the neighbors I’m with are immunocompromised.
Joseph
Nov 21 2020 at 10:13am
Happy birthday, professor. Always a pleasure to read your posts.
Comments are closed.