We use the 2019 paper, Safety in Numbers, to frame this week’s discussion.

Topics:

• The amount of exposure increases the amount of risk.
• Safety in Numbers is a 2019 update to a 2017 paper of the same name.
• Why you should get down and dirty with the numbers.
• Be careful about what stats do and don’t tell you.
• How volume affects risk potential.
• Rate vs. raw number.
• How our systems encourage familiarity with risk.

Quotes:

“A lot of statistically dodgy stuff gets published in some very, very good journals and some otherwise very good authors.”

“When something is psuedo-science, you tend to find that there are some studies that say that it works...until the very best studies show that the effect doesn’t work at all.”

“Whenever you use a concept of a rate instead of a raw number, you are assuming a linear relationship.”

Resources:

Elvik, R., & Goel, R. (2019). Safety-in-numbers: An updated meta-analysis of estimates. Accident Analysis & Prevention, 129, 136-147.

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