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Perceived risk vs actual risk

  • by JW

We are much more likely to die from a car accident or air pollution than any form of influenza


The issues around the coronavirus are multiple and complex.


Xenophobia has been one response from some:

‘Exeter is better than this’ – Racist coronavirus attacks on Asians condemned by MP and University |

And populists are certainly taking advantage:

Ill will: Populism and the coronavirus |

“But before populists crow their vindication, we need to see how our populist president handles any of this. If globalism’s weakness is technocratic naïveté, populism’s faults are ignorance, incompetence and paranoia. Nothing about President Trump’s response so far instills confidence that he’s ready for the kind of crisis that Candidate Trump would have been quick to recognize and politically exploit. And the fact that Rush Limbaugh spent yesterday declaring that the coronavirus is no worse than the common cold…”

The Coronavirus Is More Than a Disease. It’s a Test. |


So, can the coronavirus be compared to ‘the common cold’?

“About 3.4 percent of confirmed cases of the new coronavirus – known as COVID-19 – have died, far above seasonal flu’s fatality rate of under 1 percent, the World Health Organisation said this week. Most experts believe the death rate is nearer 1 percent, once mild cases are taken into account.”

Coronavirus cases reach 100,000 worldwide – with 3,400 confirmed deaths |


To compare with the annual mortality rate from influenza:

Winter of 2017/18: Three times more people dying from flu in UK than last winter |

Winter of 2019/20: Flu cases soar by 25% in a week as 15 die and hundreds end up in intensive care with fast-spreading virus |


But what about mortality rates from less newsworthy causes?

“A total of 1,784 people were killed in reported road traffic accidents in Great Britain in 2018, and 1,793 deaths were reported in 2017, according to the RAC.

“Between 28,000 and 36,000 deaths a year are attributed to long-term exposure to air pollution, according to the government.”

People living in UK towns and cities 25 times more likely to die from air pollution than car crash, charity warns |


In the US, the leading cause of fatalities amongst teenagers is traffic accidents:

Mortality Among Teenagers Aged 12-19 Years: United States |

If a disease were to kill 145 teenagers in one year in the UK, there would be public outcry:

Road accidents biggest global killer of teenagers | bbc.


Air pollution is now seen as a major contributor to early deaths:

“Working out the damage done by air pollution is much harder than something like car accidents, for which we have firm figures, because it typically aggravates the effects of common disorders such as respiratory diseases…

“Yet another way to express the risk is that there are 120 extra deaths per every 100,000 people per year. Put that way, it might not sound too bad. But we don’t regard, say, the three people murdered in Europe per 100,000 per year as remotely acceptable.”

Does air pollution really kill nearly 9 million people each year? |

If an infection were to kill that many people worldwide in one year, there would be panic:

Air pollution – ScienceDaily


Here’s an excellent infographic from Susanna Hertrich looking at how our perception of risk is very wrong – produced ten years ago when the fear was bird flu:

Reality Checking: Actual Hazard vs. Public Outrage |

Risk perception |


And here’s part of an excellent piece on why we ignore the risks around traffic and pollution and exaggerate those around influenza:


Perceived Risk vs. Actual Risk

I’ve written repeatedly about the difference between perceived and actual risk, and how it explains many seemingly perverse security trade-offs. Here’s a Los Angeles Times op-ed that does the same. The author is Daniel Gilbert, psychology professor at Harvard. (I just recently finished his book Stumbling on Happiness, which is not a self-help book but instead about how the brain works. Strongly recommended.)

The op-ed is about the public’s reaction to the risks of global warming and terrorism, but the points he makes are much more general. He gives four reasons why some risks are perceived to be more or less serious than they actually are:

  1. We over-react to intentional actions, and under-react to accidents, abstract events, and natural phenomena.

    That’s why we worry more about anthrax (with an annual death toll of roughly zero) than influenza (with an annual death toll of a quarter-million to a half-million people). Influenza is a natural accident, anthrax is an intentional action, and the smallest action captures our attention in a way that the largest accident doesn’t. If two airplanes had been hit by lightning and crashed into a New York skyscraper, few of us would be able to name the date on which it happened.

  2. We over-react to things that offend our morals.

    When people feel insulted or disgusted, they generally do something about it, such as whacking each other over the head, or voting. Moral emotions are the brain’s call to action.

    He doesn’t say it, but it’s reasonable to assume that we under-react to things that don’t.

  3. We over-react to immediate threats and under-react to long-term threats.

    The brain is a beautifully engineered get-out-of-the-way machine that constantly scans the environment for things out of whose way it should right now get. That’s what brains did for several hundred million years — and then, just a few million years ago, the mammalian brain learned a new trick: to predict the timing and location of dangers before they actually happened.

    Our ability to duck that which is not yet coming is one of the brain’s most stunning innovations, and we wouldn’t have dental floss or 401(k) plans without it. But this innovation is in the early stages of development. The application that allows us to respond to visible baseballs is ancient and reliable, but the add-on utility that allows us to respond to threats that loom in an unseen future is still in beta testing.

  4. We under-react to changes that occur slowly and over time.

    The human brain is exquisitely sensitive to changes in light, sound, temperature, pressure, size, weight and just about everything else. But if the rate of change is slow enough, the change will go undetected. If the low hum of a refrigerator were to increase in pitch over the course of several weeks, the appliance could be singing soprano by the end of the month and no one would be the wiser.

It’s interesting to compare this to what I wrote in Beyond Fear (pages 26-27) about perceived vs. actual risk…

Perceived Risk vs. Actual Risk |