A micromort (from

micro- ''Micro'' (Greek letter μ, Mu (letter), mu, non-Italic type, italic) is a metric prefix, unit prefix in the metric system denoting a factor of one millionth (10−6). It comes from the Ancient Greek, Greek word (), meaning "small". It is the ...

and mortality) is a unit of

risk In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environ ...

defined as a one-in-a-million chance of

death Death is the end of life; the irreversible cessation of all biological functions that sustain a living organism. Death eventually and inevitably occurs in all organisms. The remains of a former organism normally begin to decompose sh ...

. Micromorts can be used to measure the riskiness of various day-to-day activities. A microprobability is a one-in-a million chance of some event; thus, a micromort is the microprobability of death. The micromort concept was introduced by Ronald A. Howard who pioneered the modern practice of

decision analysis Decision analysis (DA) is the Academic discipline, discipline comprising the philosophy, methodology, and professional practice necessary to address important Decision making, decisions in a formal manner. Decision analysis includes many procedures ...

. Micromorts for future activities can only be rough assessments, as specific circumstances will always have an impact. However, past historical rates of events can be used to provide a rough estimate.

Sample values

Baseline

Leisure and sport

Travel

Activities that increase the death risk by roughly one micromort, and their associated cause of death: * Travelling 6 miles (9.7 km) by

motorcycle A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...

(collision) * Travelling 17 miles (27 km) by

walking Walking (also known as ambulation) is one of the main gaits of terrestrial locomotion among legged animals. Walking is typically slower than running and other gaits. Walking is defined as an " inverted pendulum" gait in which the body vaults o ...

(collision) * Travelling 10 miles (16 km) or 20 miles (32 km) by

bicycle A bicycle, also called a pedal cycle, bike, push-bike or cycle, is a human-powered transport, human-powered or motorized bicycle, motor-assisted, bicycle pedal, pedal-driven, single-track vehicle, with two bicycle wheel, wheels attached to a ...

(collision) * Travelling 230 miles (370 km) by

car A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people rather than cargo. There are around one billio ...

(collision) (or 250 miles) * Travelling 1,000 miles (1,600 km) by jet airplane (collision) * Travelling 6,000 miles (10,000 km) by

train A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

(collision)

Other

Increase in death risk for other activities on a per-event basis: *

Hang gliding Hang gliding is an air sports, air sport or recreational activity in which a pilot flies a light, non-motorised, fixed-wing aircraft, fixed-wing heavier-than-air aircraft called a hang glider. Most modern hang gliders are made of an aluminium al ...

– 8 micromorts per flight * Ecstasy (MDMA) – 0.5 micromorts per tablet, rising to 13 if using other drugs * Giving birth ( vaginal) – 120 micromorts * Giving birth ( caesarean) – 170 micromorts *

AstraZeneca AstraZeneca plc () (AZ) is a British-Swedish multinational pharmaceutical and biotechnology company with its headquarters at the Cambridge Biomedical Campus in Cambridge, UK. It has a portfolio of products for major diseases in areas includi ...

vaccination against

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

– 2.9 micromorts *

infection at age 10 – 20 micromorts * COVID-19 infection at age 25 – 100 micromorts * COVID-19 infection at age 55 – 4,000 micromorts * COVID-19 infection at age 65 – 14,000 micromorts * COVID-19 infection at age 75 – 46,000 micromorts * COVID-19 infection at age 85 – 150,000 micromorts () Text was copied from this source, which is available under
Creative Commons Attribution 4.0 International License
.

Value of a micromort

Willingness to pay

An application of micromorts is measuring the value that humans place on risk. For example, a person can consider the amount of money they would be willing to pay to avoid a one-in-a-million chance of death (or conversely, the amount of money they would receive to accept a one-in-a-million chance of death). When offered this situation, people claim a high number. However, when looking at their day-to-day actions (e.g., how much they are willing to pay for safety features on cars), a typical value for a micromort is around $50 (in 2009). This is not to say the $50 valuation should be taken to mean that a human life (1 million micromorts) is valued at $50,000,000. Rather, people are less inclined to spend money after a certain point to increase their safety. This means that analyzing risk using the micromort is more useful when using small risks, not necessarily large ones.

Value of a statistical life

Government agencies use a nominal Value of a Statistical Life (VSL) – or Value for Preventing a Fatality (VPF) – to evaluate the cost-effectiveness of expenditure on safeguards. For example, in the UK, the VSL is £1 million GBP in 1997 value (equivalent to £ million in ). Since road improvements have the effect of lowering the risk of large numbers of people by a small amount, the UK Department for Transport essentially prices a reduction of 1 micromort at £1.60. The US Department of Transportation uses a VSL of US$6.2 million, pricing a micromort at US$6.20.US Department of Transportation, "Treatment of the Economic Value of a Statistical Life in Departmental Analyses—2011 Interim Adjustment", 2011, http://www.dot.gov/policy/transportation-policy/treatment-economic-value-statistical-life

Chronic risks

Micromorts are best used to measure the size of ''acute'' risks, i.e. immediate deaths. Risks from lifestyle, exposure to

air pollution Air pollution is the presence of substances in the Atmosphere of Earth, air that are harmful to humans, other living beings or the environment. Pollutants can be Gas, gases like Ground-level ozone, ozone or nitrogen oxides or small particles li ...

, and so on are ''chronic'' risks, in that they do not kill straight away, but reduce life expectancy. Ron Howard included such risks in his original 1979 work, for example, an additional one micromort from: * Drinking 0.5 liter of

wine Wine is an alcoholic drink made from Fermentation in winemaking, fermented fruit. Yeast in winemaking, Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made f ...

(cirrhosis of the liver)* Howard, Ro
Risky Decisions
(Slide show), Stanford University *

Smoking Smoking is a practice in which a substance is combusted, and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, whi ...

1.4 cigarettes (cancer, heart disease) * Spending 1 hour in a coal mine (black lung disease) * Spending 3 hours in a coal mine (accident) * Living 2 days in New York or Boston in 1979 (air pollution) * Living 2 months with a smoker (cancer, heart disease) * Drinking Miami water for 1 year (cancer from chloroform) * Eating 100 charcoal-broiled steaks (cancer from benzopyrene) * Traveling 6000 miles (10,000 km) by jet (cancer due to increased background radiation) Such risks are better expressed using the related concept of a microlife.

Notes

References

External links

Micromorts - We are all going to die
Medical aspects of death Health risk Units of measurement Probability assessment