You’ve probably heard this story before: “Once upon a time, there were three little pigs.” Each pig is building a house. The first one builds a house from straw; the second one, sticks; and the third one, from bricks. Why do these three similar-seeming pigs use such different building materials? The original story doesn’t tell us why. If you had to guess, you might imagine that cost is a factor — and, who knows, maybe supply-chain issues. It could also be that the three pigs have different risk preferences because a house isn’t just for sleeping in. It’s also protection against you know who…
DISNEY: Who’s afraid of the Big Bad Wolf, Big Bad Wolf, Big Bad Wolf. Who’s afraid of the Big Bad Wolf?
“The Three Little Pigs” is an English fairy tale which was later turned into a short animated film produced by Walt Disney. But the Big Bad Wolf also shows up in German folk tales, like “Little Red Riding Hood” from the Brothers Grimm. And in the Russian musical story “Peter and the Wolf,” by Sergei Prokofiev. And centuries earlier too, in one of Aesop’s fables, “The Boy Who Cried Wolf.” All these fictional wolves have something in common: they want to eat you and ruin the things you treasure. How accurate is that view of wolves?
Jennifer RAYNOR: Well, I don’t know about fairy tales, but I know that the colonial history of wolves in the United States would suggest that, at that time, wolves were really problematic.
Jennifer Raynor is a natural-resource economist at Wesleyan University. Before the Europeans came to America, she says, wolves were everywhere.
RAYNOR: They ranged across almost all of the lower 48 states. There were probably millions of wolves.
And these wolves were “problematic,” as Raynor puts it, because wolves don’t only eat cartoon pigs. They’ll eat all kinds of livestock, including the animals being raised by the settlers.
RAYNOR: In the 1800s and early 1900s, we started putting bounty programs on wolves, which means the federal or state government will pay you money to provide a wolf pelt.
These bounty programs continued into the 1960s; at the time, a dead wolf might fetch as much as $50 — the equivalent of around $450 today.
RAYNOR: These programs were super-effective.
RAYNOR: We drove wolves, essentially, to local extinction across the lower 48 states.
Stephen DUBNER: What does that mean, “local extinction”?
RAYNOR: That means there was not a single wolf left in the lower 48 states.
Some scholars call this period of American history the Age of Extermination. The economic expansion of the U.S. created a huge demand for fur, leather, and meat; the populations of elk, beaver, bison, and passenger pigeon were also decimated. But let’s get back to the wolf. If you haven’t been following wolf news closely, here are a few key things to know: As Jennifer Raynor said, the U.S. wolf population fell from the millions to roughly zero by the 1960s. But thanks to the Endangered Species Act, the U.S. began to bring the wolf back. But now there is a movement to kill off the wolves again, for the same reasons as before: they are a threat to the animals we prefer — and, theoretically, a threat to us too.
DISNEY: Who’s afraid of the Big Bad Wolf?
Today on Freakonomics Radio: a new view of the big bad wolf.
RAYNOR: My view of the wolf is that they have an important ecological role. They’re also incredibly impactful on the economy.
“Impactful on the economy” how?
Dominic PARKER: It’s a great, great question to think about.
And if you think the Big Bad Wolf meme is outdated, don’t even get us started on Bambi.
Jack ZIPES: That is a stupid inaccuracy.
Could the wolf you think of as a cold-blooded killer actually save your life?
RAYNOR: Let’s get this thing done today.
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Earlier, we described Jennifer Raynor as a “natural-resource economist.” What does a natural-resource economist do?
RAYNOR: We think about how to manage natural resources in a way that’s both sustainable and generates economic benefits.
DUBNER: That sounds virtuous. Is it as virtuous as it sounds, or does it have enough economics in it to make it very pragmatic?
RAYNOR: It’s pragmatic in that we can’t generate economic benefits from resources that have been eliminated or depleted. The main thing that economics brings to the table when it comes to natural resources is thinking about trade-offs. We have limited money for conservation, for example. And where do we spend that? We can’t necessarily protect everything that we want to protect. What might give us the biggest bang for the buck, so to speak?
Raynor has studied a variety of animals and habitats. For a time, she worked with the National Oceanic and Atmospheric Administration in Hawaii, studying fishing yields. But most of her time has been spent on land; she got her Ph.D. at the University of Wisconsin-Madison.
RAYNOR: I’ve been at wolves since about 2012.
DUBNER: And what attracted you to wolves?
RAYNOR: I think living in Wisconsin and just hearing all these controversies about wolf expansion in the state, and I just became really interested in this fight around wolves. I felt like this was a good area for an economist to think about trade-offs.
As you may know, the gray wolf — or Canis Lupus — shares more than 99.9 percent of its DNA with dogs. There are roughly 30 wolf subspecies — none of which, for the record, are technically known as “Big Bad.” The wolf is thought to be native to North America, Asia, and parts of Europe — and some other countries wiped out their wolves, like the U.S. So where did today’s wolves come from, if there were none left in the U.S.?
RAYNOR: They remained in Canada. The Canadian wolf population is actually how we now have wolves in the United States.
DUBNER: So, every American wolf now is a Canadian import?
RAYNOR: At this period where all these wolves were eradicated, there were a few little wolf populations left in Minnesota. And this was connected to the Canadian wolf population. Over the 1970s and 80s, wolves moved back across Minnesota, Wisconsin, and the Upper Peninsula of Michigan from this Canadian holdout.
DUBNER: And how many states outside the Midwest have a significant wolf population?
RAYNOR: The Western states are Montana, Idaho, and Wyoming, around the Greater Yellowstone area, and they’ve expanded into Oregon and Washington. In the Southwest, there’s a subspecies of the Gray Wolf called the Mexican Wolf that was reintroduced in 1998 to Arizona and New Mexico.
Today, there are thought to be around 5,500 wolves in the U.S. — nothing like the millions there used to be, but a lot more than zero. The reintroduction of wolves was only made possible by powerful federal legislation. The Age of Extermination was followed, eventually, by the Age of Conservation, a reckoning that our natural world was under assault. In 1973, President Nixon signed into law the Endangered Species Act, or E.S.A. It has been amended several times since then, but the premise remains the same: if a species is considered endangered, it and its habitats are placed under protection, backed by penalty of law.
RAYNOR: Right now, there’s about 1,600 species in the United States listed as threatened or endangered. The reality is: it’s expensive. It’s expensive to protect all these species, and a lot of money is spent every year to do that. I think the United States has done a really good job of thinking about which species are at risk and trying to at least identify them so that we know where the money ideally should be spent.
The agency in charge of administering the E.S.A. is the U.S. Fish and Wildlife Service. It spends more than $200 million a year to do so, with much more money spent by state and local agencies. Some of the animals currently listed as endangered: the Houston toad, the whooping crane, and the Florida panther.
RAYNOR: We, in general, have been really successful with the Endangered Species Act, depending on how you define “success.” Ninety-nine percent of species that have been listed have been prevented from going extinct, but a very small number have been recovered.
DUBNER: “Recovered” meaning brought back to real robustness, is that what that means?
RAYNOR: That’s right. We’re no longer worried that this animal is threatened with extinction.
These recovered species include the bald eagle, the Louisiana black bear, and the Virginia northern flying squirrel, all of which have been delisted from E.S.A. protection. The gray wolf, meanwhile, remains on the protected list in some states but has been removed in others; as we’ll hear later, individual states also have the latitude to set their own hunting policies. This can lead to controversy — and if you look at the E.S.A. as a whole, you’ll see even more controversy because the protection of endangered species has been accompanied by a string of unintended consequences. Consider land use:
RAYNOR: One big part of the U.S. Endangered Species Act is identifying critical habitats to protect. And then some restrictions will be placed on how private landowners can use that land.
Imagine you own a piece of land; maybe it’s been in your family for generations. And then you are informed that your property may become a protected habitat for the California tiger Salamander or the red-cockaded woodpecker.
RAYNOR: If this animal is listed as endangered, and your land is now restricted on building new homes, maybe you’d be proactive about eliminating that habitat — getting this species off your land, or preventing it from coming on your land — before it’s listed as protected.
“Getting a species off your land before it’s protected” is sometimes called “shoot, shovel, and shut up.” Why does a landowner even have this option? Because before a species can be officially listed, it first has to be evaluated.
RAYNOR: There’s a long scientific period where the species will be studied, a long period where people are able to comment on these proposed policies. And so there’s quite a long lag in between when a species is proposed for listing and once it’s actually listed.
Furthermore, the E.S.A. doesn’t allow the economic impact of a ruling to be factored in. So if you own some land that may be designated a protected habitat:
RAYNOR: You might chop down some forest if you think some endangered woodpecker might come in.
You can see why a landowner wouldn’t want to stand by and watch their property lose value. But preemptively destroying the natural habitat — or “shooting, shoveling, and shutting up” — plainly, these are not the intended outcomes of the Endangered Species Act. These unintended consequences have led economists like Jennifer Raynor to think hard about how to balance the costs and benefits of conservation. So how does she think about the costs and benefits of the gray wolf? You could imagine the biggest cost would be the threat to human life. So how dangerous are wolves to humans?
RAYNOR: There’s some historical record even in the colonial period that you’ll hear a wolf, but you won’t see a wolf, and that continues today. So maybe wolves seem less problematic today simply because there’s better food for them in places away from people.
DUBNER: One could imagine, if one knows very little about wolves — let’s say, me — and I say, “I live in a pretty rural county. I’ve got 10 acres. I do a little fruit farming. And all of a sudden, wolves are starting to come around.” I could imagine that there will be, on net, loss of human life because of wolves. I’m worried about those wolves actually coming to attack me or my family. Was that a general sentiment?
RAYNOR: People might be afraid of that, but I think the reality is that’s extremely unlikely.
DUBNER: Are the American wolves of today more polite than the earlier wolves because they have the Canadian breeding? They’re not killer wolves. They lost all their blood lust.
RAYNOR: Yes, that’s right. They do seem to be more polite than you’d expect, and one reason might be that they were decimated for so many years that they’ve learned how to avoid people, and that the shyer animals were the ones that survived. The occurrences of people being killed by wolves in the United States are extremely rare. I was only able to find two cases since the 1980s, when wolves started to recover.
One recent study by the Norwegian Institute for Nature Research looked at wolf attacks across North America and Europe from 2002 to 2020. It found fewer than 500 total attacks on humans, the vast majority of them from rabid wolves. During those 18 years, across many countries, there were a total of 26 recorded human deaths. In the U.S., wolves kill fewer people than bears, mountain lions, or snakes — although, to be fair, the wolf population is much smaller. But even dogs kill about 30 people a year in the U.S. — although there are an estimated 77 million dogs in the U.S. and only 5,500 wolves. Still, the bottom line is that wolves, so far at least, don’t pose much threat to human life.
But what about to livestock? Farmers and ranchers certainly have reason to oppose wolves, and a financial incentive as well. Cattle, for instance, are expensive to buy and raise; wolves pose a risk to that investment. Wisconsin Public Radio has been diligently covering the return of wolves to a state that has a lot of dairy and cattle farms. Here, from a report produced by Rich Kremer, is one cattle farmer who had a calf eaten by wolves.
W.P.R.: And there wasn’t much left of it. The head and the two front shoulders and everything else was gone.
Here’s another cattle farmer who shared his story on a YouTube channel called “Wisconsin Wolf Facts.”
FARMER: I came home from work one day, and I went out to check on the cows. And of course there was one cow that was missing, she was out in the woods. And I go out there to check on her, and she was out there with what had remained of her calf that had been eaten. They ate the bones, the stomach, everything.
And another public radio clip from a Wisconsinite talking about her family’s hunting dogs.
W.P.R.: These animals were trailing bear at the time, and one was trailing bobcat. They were attacked by wolves without any provocation and killed.
So the state of Wisconsin, along with some other states, set up a reimbursement program for farmers or ranchers whose animals are killed by wolves. Over the past five years, the payout has been less than $200,000 a year. The reimbursement price for cattle is over $1,300 per animal; for a pet dog, more than $1,400; a dead chicken yields about $19.
RAYNOR: The reimbursement program in Wisconsin started not long after wolves began to come back naturally. This program was extremely helpful to improve people’s willingness to allow wolves to come back, and to avoid this problem of “shoot, shovel, and shut up.” I think the reimbursement programs, actually, were pretty revolutionary to say: “The economics matters. Maybe we can create incentives for people to be more accepting through reimbursements.” But then the unintended consequence is: Maybe we’re not doing enough to protect our flocks if we know that we’ll be reimbursed.
DUBNER: Do you know if the reimbursement program has ever been exploited or abused? Let’s say I got sick of being a milk farmer and I decided: “Eh, I’m just going to pretend that 12 of those guys got mauled by wolves and cash out and become a painter.”
RAYNOR: I haven’t heard of that happening. I think in general, people who raise livestock really care about their animals, and they certainly don’t want them to be killed by wolves.
DUBNER: That’s fair.
RAYNOR: But the reality is, it’s quite expensive to protect your animals from wolves, especially in western states, where livestock are roaming over really huge ranches. And if your profits are already pretty slim, this is hard to do.
So there are several reasons why farmers and ranchers might oppose a major wolf repopulation. There’s another community that often registers an even stronger opposition to wolves: hunters. A lot of the animals that Americans hunt — deer, elk, boars, wild turkey — these animals are also natural prey for the gray wolf, which can be worrying to hunters.
RAYNOR: Worrying about: It’s going to be a lot harder for me to now hunt these animals, because maybe their populations have fallen. Maybe they’re more wary and they’re not just hanging around the way they used to. If my hunting quality is changing, maybe I’m not too happy.
And hunting is big business: about $27 billion a year in total expenditures — more than half of that from deer hunting. So perhaps we shouldn’t be surprised to learn that hunters, farmers, and ranchers in several states have lobbied government officials to remove the gray wolf from the Endangered Species list. With, we should say, considerable success — in Montana, Idaho, and Wyoming, for instance. In 2012, under President Obama, wolves were delisted from the Great Lakes region — but were relisted again a couple years later, after a court overruled the decision. But then in 2021, due to changes made under President Trump, wolves were completely delisted, a decision now supported by President Biden. When a given animal is delisted on the federal level, it’s up to each state to decide whether and how to protect it. Wisconsin decided to encourage hunters to go after wolves.
RAYNOR: Wisconsin had a quite controversial wolf hunt right after wolves were removed from this endangered species list. About 218 wolves were killed in less than three days. And this was about twice as many as the state wanted to have killed.
Remember, the total U.S. wolf population was only around 5,500. Wisconsin was thought to have 1,000 of these wolves — so 218 wolves killed by hunting represented a huge share. Wisconsin isn’t the only place this is happening.
RAYNOR: Idaho has a law that calls for killing 90 percent of their wolves. Montana has passed a law that allows new aggressive hunting tactics like neck-snaring or baiting traps.
In California, where there are now thought to be about 20 wolves, a Federal District Court judge recently overruled the federal decision to delist the gray wolf. This ruling argued that while wolf populations had been recovering in some places, they are still threatened elsewhere. Jennifer Raynor has been listening to both sides of this argument for a decade now, starting when the federal government delisted wolves for the first time.
RAYNOR: Living in Wisconsin at the time, there was a lot of debate about wolves in the news. It just prompted me to think about: What are we gaining by allowing wolves to spread, and what are we losing?
In case you’re a bit confused by all this wolf back-and-forthing, here’s a quick recap. When the first European settlers arrived in North America, there were millions of wolves here. During the 18th and 19th centuries, they were essentially wiped out. Under the Endangered Species Act of 1973, wolves began to return, albeit in modest numbers. Now some farmers, ranchers, and hunters have successfully lobbied to remove the wolf from the endangered list, but conservationists are worried the species might be pushed to extinction again. Got it? Coming up: the story gets more complicated, and more interesting — thanks to another animal that some people may wish were extinct:
PARKER: They’re involved in about 30,000 injuries annually, 200 of which are fatal.
What is this dangerous animal we’re talking about? And what’s the relationship between this animal and the wolf?
* * *
I want to thank you for following the other shows in the Freakonomics Radio Network: No Stupid Questions, People I (Mostly) Admire, and Freakonomics, M.D. All three of these shows have fast-growing audiences, and you are the reason why. So thanks for all the love you’ve been showing not only for Freakonomics Radio, but all our podcasts — and keep your ears peeled for a couple new podcasts this spring, including one that’s built around the domesticated descendant of the wolf.
* * *
When you hear the word “wolf,” what do you think?
ZIPES: The wolf is sort of treacherous. Very powerful, very smart, but treacherous.
That is Jack Zipes.
ZIPES: I’m a professor emeritus from the University of Minnesota.
His field: German comparative literature. His specialty: fairy tales. And Zipes thinks that fairy tales have deeply influenced how we think about wolves.
ZIPES: One could even blame Little Red Riding Hood for all the killings of wolves today in the United States.
Minnesota, we should say, is a good place for the wolf-obsessed. There are plenty of gray wolves there, and the N.B.A. team is called the Timberwolves. Jack Zipes knows about wolves, he cares about wolves, but the animal he’s been obsessing over would seem to be far less “treacherous” than the wolf. Zipes recently published a new translation of a 1922 novel by the Austrian author Felix Salten. The novel is called The Original Bambi: The Story of a Life in the Forest. You may think you know the story of Bambi from the famous Walt Disney film. But trust me, you don’t really know the story of Bambi. Walt Disney was known for turning fairy tales into box-office hits, a process that often required brightening up some of the stories’ darker themes. This was very much the case when Bambi was adapted from novel to animated film. The novel is a coming-of-age story about a young deer learning to survive in a hostile world. Felix Salten was Jewish, and Jack Zipes says that the novel incorporated Salten’s experiences with anti-Semitism.
ZIPES: It’s quite clear that Bambi was Salten and Salten was Bambi. He understood the dilemma not only of Jews but of all minority groups. When you are born to be killed, then your life is going to be tragic from the very beginning, from the time you jump out of the womb. It pre-figures the Holocaust because the forest is wiped out, and these killers manage to destroy the lives of all the animals in the forest.
That, at least, was the Bambi novel. The Disney film, released about 20 years later, during World War II, told a different story.
ZIPES: They made it into the sweetest, most poisonous, and putrid film I’ve ever seen.
Disney’s Bambi is an innocent creature who only wants to live happily with his forest friends:
MRS. QUAIL: Good morning, Bambi.
BABY QUAILS: Good morning, Young Prince!
But the innocent animals are beset by wicked hunters. Generations of children who saw the film would weep when Bambi’s mother was killed.
ZIPES: I don’t think that Disney himself thought of doing an animal-rights film, but it’s been noted that he did care for animals.
The takeaway from the Bambi movie is that deer are lovely and gentle, and worthy of our protection. If, however, you are an economist, especially a natural-resource economist, you may see it differently.
PARKER: Where deer are overabundant, they damage crops, they damage forests, they possibly are involved in spreading Lyme disease and chronic-wasting disease.
That is Dominic Parker, an economist at the University of Wisconsin-Madison who has been studying wolves with Jennifer Raynor. We’ve already heard about some of the costs that wolves impose, particularly on livestock, but Parker and Raynor have been examining the benefits, too.
PARKER: One avenue for wolves to have a positive economic impact on local communities is through their control of deer.
The first thing to say about deer in America is that there are a lot of them.
PARKER: Around the time of Christopher Columbus, it was estimated there were maybe 30 to 35 million white-tailed deer in the continental U.S. That number dwindled down to less than 500,000 around 1900. Across the whole country today, the lower 48, we’re back up into the 30-35 million white-tailed deer range.
Why has the deer population exploded like this? One reason is that hunting has been in decline. In just the five years from 2011 to 2016, deer hunting in the U.S. fell by around 25 percent. Why? One reason, Dominic Parker says, is a lifestyle shift.
PARKER: We’re spending less time outdoors engaged in outdoor activities in general.
There’s also a shift in where we live.
PARKER: You have a much larger population of Americans in cities or in suburbs. And in both of those places, there’s fewer opportunities to hunt.
There’s also the phenomenon known as “the Bambi effect” — a reluctance to kill deer based on the Disneyfied notion that they are lovely and gentle. And so: untroubled by hunters and valued for their loveliness, deer continue to multiply — especially in the suburbs, where they impose a variety of costs. They eat the shrubbery; they spread disease; and most serious of all, they wander onto roadways and collide with cars, trucks, motorcycles, and bicycles. This is known to Parker and other researchers as a D.V.C., or a deer-vehicle collision.
PARKER: One million deer-vehicle collisions per year results in about 30,000 injuries annually, 200 of which are fatal.
Wait, what? How many deer-vehicle collisions every year?
RAYNOR: There’s about one to two million deer-vehicle collisions every year in the United States.
And the human toll was what?
PARKER: 30,000 injuries annually, 200 of which are fatal.
In a country with more than 35,000 traffic deaths a year — a number that rose during the pandemic, by the way — some 200 deaths from deer-vehicle collisions may not sound like much. Still: that’s 200 deaths, and 30,000 injuries, and billions of dollars in property damage — all attributed to the spawn of Bambi. Deer-vehicle collisions account for nearly 10 percent of all vehicular crashes in the U.S.
RAYNOR: If you ask a room of 10 people how many have hit a deer, you’d see a lot of hands being raised.
PARKER: It is not hard to find friends and family members who have been involved not in only one deer-vehicle collision, but multiple deer-vehicle collisions. It’s a very salient issue for lots of people.
And why does this happen so often, other than the fact there are so many deer (and so many cars)? Maybe you’ve heard the phrase “like a deer caught in the headlights”? Well, that is a real thing. As deer biologists explain, the bright lights of an oncoming car do temporarily blind a deer. Their eyes are dilated in the darkness, or in the dim light of dusk and dawn, when deer are most active. So when the headlights hit them, they tend to stand still and wait for their vision to return to normal. Also: waiting for a car to hit them.
PARKER: Approximately $10 billion in economic cost can be attributed annually to those deer-vehicle collisions.
RAYNOR: This is a really difficult problem to solve. Americans drive a lot. There’s been big increases in deer-vehicle collisions since the 1990s, nationwide. Traditional measures to reduce collisions have been fairly unsuccessful on a large scale. The things that we’ve traditionally done is put up a deer-warning sign. And have you slowed down when you pass a deer-warning sign? So those aren’t very effective. There are other things that are quite effective but extremely expensive, like putting in fences along roadsides with some kind of overpass or underpass along the road. These are so expensive you can really only do this where collisions are just extremely frequent.
It is possible that the long-promised fleet of autonomous vehicles will be much better at dodging deer.
RAYNOR: If they can see deer on the side of the road, in theory, they could slow down. So the reaction time of an autonomous vehicle certainly is going to be better than a person. One big problem is that you don’t always see the deer. They might just dart in front of your car.
Some cars already come equipped with a deer-avoidance system — there’s a Bentley that offers this, although that car costs around $185,000.
RAYNOR: There still might be some problems where deer just jump into your car. I’ve had friends who a deer jumped right into the side of their car after they had already passed.
But what if there was an easier, and cheaper, way to cut down on deer-vehicle collisions? What if there was a shortcut? And what if that shortcut was wolves? That’s what Jennifer Raynor, Dominic Parker, and a third economist named Corbett Grainger wanted to know.
RAYNOR: We wanted to look at the effects of wolves on this overabundant deer population.
The logic works, doesn’t it? Wolves are predators; among their prey are deer; could more wolves mean fewer deer and therefore fewer deer-vehicle collisions? The economists found some clues in research done by ecologists about the reintroduction of wolves in Yellowstone Park.
RAYNOR: The papers in Yellowstone have been a little bit controversial in the ecological community, but this first set of papers that came out basically said: When wolves come in, they create what’s known as a “landscape of fear.” Elk are now afraid of wolves.
Here’s how this so-called “landscape of fear” was created. Theoretically, the wolves around Yellowstone reduced the deer population; with fewer deer to eat leaves and branches, trees and bushes grew better, which meant more berries — and since bears eat berries, that meant more bears. Which meant fewer elk — because bears, in addition to eating berries, also eat elk.
RAYNOR: Basically, wolves are affecting elk and other prey species in ways that both reduce their population and potentially change how they’re behaving, and this has big cascades through the ecosystem.
If that whole daisy chain were true — the wolf-deer-berry-bear-elk daisy chain — what about the wolf-deer-car crash daisy chain? Do more wolves equal fewer deer and therefore fewer deer-vehicle collisions? The three economists set out to gather the relevant data; they focused on Wisconsin.
RAYNOR: There’s a couple of reasons we wanted to focus on Wisconsin. The first was practical. The data are great in Wisconsin. They’ve done a wonderful job tracking wolves, and they do a great job tracking deer and the other data that we need. But there are other reasons why Wisconsin is interesting. This is a human-dominated landscape. This is a place where people are farming, where people are raising livestock, where there’s cities, and wolves have just been allowed to spread across these areas naturally. And so it’s an interesting place to think about: When wolves come into a place that isn’t a national park, what’s the effect on the economy?
Also, Wisconsin has a lot of deer — about 1.6 million in a state with six million people. The researchers got their data from the Wisconsin Department of Natural Resources and the Wisconsin Department of Transportation; it covered the years 1988 to 2010.
RAYNOR: We ask whether wolves can reduce the frequency of deer-vehicle collisions, either by changing deer populations, reducing populations, or changing deer behavior. For example, moving deer away from roadsides.
And what’d they find?
RAYNOR: We find that wolf presence reduces the frequency of deer-vehicle collisions by about a quarter. And this is valued at about $11 million per year statewide.
DUBNER: Does that include loss of life?
RAYNOR: Yeah. What this $11 million includes is spending on fixing your car and so on. But it also includes other things, like lost productivity in wages, payments for healthcare and hospital services, people’s willingness to pay to avoid dying in a vehicle collision. In Wisconsin, there are about eight people killed on average in a year by deer-vehicle collisions. And if we reduce that by about a quarter, then we would, maybe, expect two fewer people killed in a year. When we came into this project, we didn’t know if wolves were going to create a benefit or a cost. Are wolves driving deer out of forests and into roads? That could have been equally plausible. We just let the data tell us what is happening. What we’re hoping to do is just provide more information about another piece of how wolves affect people.
DUBNER: Persuade me that what you’re observing here is causal and not just correlational. That the wolves’ behavior is actually changing the deer behavior in such a way as to result in fewer deer-vehicle collisions, and not that there’s some other input here.
RAYNOR: The model that we’re using does three things. It’s looking at: How do deer-vehicle collisions change when wolves enter a county? We’re looking at before- versus after-wolves. You might be concerned there’s other stuff going on at the same time as wolves. We also look at what’s happening in other counties that don’t have wolves to try to see: How does their deer-vehicle collisions change around the same time? That helps us control for other things that might be driving changes in deer-vehicle collisions. Then we do a third thing where — now you might be worried: “Maybe deer-vehicle collisions are declining in all these places because of anti-lock brakes, or better road maintenance, or changes in vehicles,” and so on. We also now compare these changes to what’s happening with other types of collisions, collisions that are not caused by deer, and that helps us control for broader changes in vehicle and roadway safety that might be happening at the same time.
Raynor and her co-authors are now planning to study deer-vehicle collisions in other states that have wolves. The costs and benefits of wolves may well differ from place to place. Wolves are wolves and deer may be deer, but what if there are also, say, a lot of coyotes?
RAYNOR: When wolves come in, we might see some really different dynamics in how coyotes act with regard to killing livestock. It’s actually not that apparent to us that, when wolves come in, livestock predation goes up because, if wolves come in, they kill a bunch of coyotes or drive them out, they’re no longer killing livestock. The effects of that are, maybe, unclear until we do some tests with data.
So outcomes will vary from place to place. But looking at Wisconsin, the wolf math is compelling. Remember, Raynor and her colleagues calculate $11 million a year in benefits from fewer deer-vehicle collisions; meanwhile, the state pays out only less than $200,000 a year to compensate people for livestock and pets killed by wolves. Of course, the math isn’t as attractive if those are your animals being killed.
RAYNOR: Even though the percent of livestock being killed is relatively small, it can be very concentrated. A wolf might come to one ranch and kill a large number of animals. To that person, it’s very problematic, especially if profit margins are really slim to begin with.
Dominic Parker says one solution would be to expand the reimbursement program.
PARKER: There’s a couple programs, one in Arizona, where landowners are being paid for wolf presence. This is going beyond a compensation program where you’re just paid as a landowner if your livestock is harmed. What if we pay landowners for accommodating wolves in a way that we can verify that wolves are using part of their land? This creates a profit opportunity where a landowner can begin to be innovative and say, “How could I manage my land a little differently to encourage the species that other people value to occupy my land?”
And what about hunters? How could they perhaps be persuaded that wolves are not killing too many of the other animals they hunt?
RAYNOR: In Wisconsin, the Department of Natural Resources guesses that each wolf eats about 18 to 20 deer per year out of a population of 1.6 million, and there’s about a thousand wolves in Wisconsin right now.
DUBNER: So really, rounding error.
RAYNOR: Yes. Really, rounding error.
But this leads to another question, and a puzzle. There are 1,000 wolves in Wisconsin; they each eat around 20 deer per year. So that’s 20,000 fewer deer per year. That’s just a bit over 1 percent of the total deer population of Wisconsin of 1.6 million. So how can a 1 percent reduction of deer lead to what Jennifer Raynor says is a 25 percent reduction in deer-vehicle collisions? One hypothesis is that the “landscape of fear” observed in Yellowstone Park can also happen in more populated areas, like Wisconsin.
RAYNOR: One thing that might be happening is that wolves are traveling down roads, deer are avoiding these areas because they don’t want to get killed, which in turn reduces vehicle collisions. But we haven’t radio-collared deer to estimate this effect. This is just something that we think is plausible based on some previous radio-collar studies.
DUBNER: But why are wolves then not getting hit by cars all the time? Do wolves actually sense the danger of a vehicle and get away, though?
RAYNOR: It would seem so, because in Wisconsin, there are only about 20 collisions with wolves in a year.
DUBNER: Are you saying that wolves are a lot smarter than deer? Or you’re not quite willing to commit to that?
RAYNOR: I think wolves are better at avoiding being hit by cars than deer.
DUBNER: That sounds smart.
RAYNOR: The reasons for that are unclear.
Let’s say you are convinced that the presence of wolves, at least in moderation, is a net economic gain — that the benefits from fewer deer-vehicle collisions outweigh the costs borne by hunters, farmers, and ranchers. But even if you believe all that, there’s still public opinion. There’s still Bambi and the Big Bad Wolf. Imagine you’re a wildlife manager in a state that’s thinking about letting the wolf population grow. You may even use the research we’ve been talking about today as ammunition for your argument: just think of the human lives saved, and the money saved, by reducing deer-vehicle collisions. And then you are hit with a headline — like this recent one from Bloomberg News: “Colorado Wolf Pack Kills Cattle for First Time in Over 70 Years.” A drop in car crashes doesn’t make the news; but wolf attacks do.
RAYNOR: Wildlife managers are in a really difficult position here. The costs are really evident. Livestock ranching is really important in the western states and wolves are killing livestock. It happens. So I think states are in a really tricky position between balancing the people who are pro-wolf and anti-wolf.
Another factor to consider: modern wolves may be less likely to attack livestock than they were in the old days.
RAYNOR: Today, livestock predation is much smaller because deer are very, very abundant and other prey species are now more abundant than they were in the colonial period.
DUBNER: Meaning the wolves would rather go eat the deer than eat my cow.
RAYNOR: In general, yes. That’s right. In general, wolves are killing natural prey species — deer and other smaller animals — rather than livestock.
DUBNER: Considering that deer are not the smartest animal in the animal kingdom, would something like fake wolf cut-outs planted along highways perform some useful function?
RAYNOR: Well, that’s interesting, because I did come across a study where they were using scents of leopards to see if prey would behave differently if they smell the scent of a predator around, and those do seem promising. The one concern you might have is: You have to maintain those policies forever, so you can never stop. We need to deal with overabundant deer populations first and foremost. The method that we have traditionally relied on to control deer populations is hunting. The average deer hunter right now is middle-aged, and they’re just having problems recruiting new, younger hunters. I think this is going to be a really significant problem if we can’t find either a way to recruit more people to hunt deer over the long-term, or some other way to control deer populations. Things are going to get out of control.
DUBNER: Reading between the lines, it makes me think that video games and social media are driving young deer hunting down, which means driving deer up, which means driving deer-vehicle collisions up, which means that video games and social media cause traffic deaths. Is that about accurate?
RAYNOR: Well, that’s quite a leap, but we certainly know that new generations have different preferences about how to spend their time.
You, too, have your own preferences about how to spend your time — so thanks for spending it today with Jennifer Raynor, Dominic Parker, and Jack Zipes, with all the deer and all the wolves, and with me. My name is Stephen Dubner.
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Freakonomics Radio is produced by Stitcher and Renbud Radio. This episode was produced by Zack Lapinski; we had help this week from Jeremy Johnston. Our staff also includes Alison Craiglow, Greg Rippin, Gabriel Roth, Ryan Kelley, Mary Diduch, Rebecca Lee Douglas, Morgan Levey, Julie Kanfer, Emma Tyrrell, Jasmin Klinger, Eleanor Osborne, Lyric Bowditch, Jacob Clemente, and Alina Kulman. Our theme song is “Mr. Fortune,” by the Hitchhikers; the rest of the music this week was composed by Luis Guerra. You can follow Freakonomics Radio on Apple Podcasts, Spotify, Stitcher, or wherever you get your podcasts.
- The Original Bambi: The Story of a Life in the Forest, by Felix Salten (translated by Jack Zipes, 2022).
- “Wolves Will Regain Federal Protection in Much of the U.S.,” by Catrin Einhorn (The New York Times, 2022).
- “Road accidents in the United States – Statistics & Facts,” by Mathilde Carlier (Statista, 2022).
- “‘Bambi’ Is Even Bleaker Than You Thought,” by Kathryn Schulz (The New Yorker, 2022).
- “Colorado Wolf Pack Kills Cattle for First Time in Over 70 Years,” by Vincent Del Giudice (Bloomberg, 2021).
- “Wolves Make Roadways Safer, Generating Large Economic Returns to Predator Conservation,” by Jennifer L. Raynor, Corbett A. Grainger, and Dominic P. Parker (PNAS, 2021).
- “Bentley Flaunts Deer Avoidance System in Parallel Universe of Christmas Car Commercials,” by Benny Kirk (Autoevolution, 2021).
- “2020 Wisconsin Agricultural Statistics,” (Wisconsin Department of Agriculture, Trade and Consumer Protection, 2020).
- “As Wolves Recover, Calls in Wisconsin to End Endangered Species Listing Grow,” by Rich Kremer (Wisconsin Public Radio, 2019).
- “Hunting in America: An Economic Force,” by Tom Allen, Eric Olds, Rob Southwick, Ben Scuderi, Doug Howlett, and Lorna Caputo (Southwick Associates, 2018).
- “Impact of Two of the World’s Largest Protected Areas on Longline Fishery Catch Rates,” by John Lynham, Anton Nikolaev, Jennifer Raynor, Thaís Vilela, and Juan Carlos Villaseñor-Derbez (Nature, 2020).
- “Riparian Vegetation Recovery in Yellowstone: The First Two Decades After Wolf Reintroduction,” by William J. Ripple and Robert L. Beschta (Biological Conservation, 2016).
- “Federal Court Puts Gray Wolf Back on Endangered Species List,” (Associated Press, 2014).
- “Wolf Wars: America’s Campaign to Eradicate the Wolf,” (PBS Nature, 2008).
- “Wolf Reintroduction, Predation Risk, and Cottonwood Recovery in Yellowstone National Park,” by William J. Ripple and Robert L. Beschta (Forest Ecology and Management, 2003).