Base rate (and base-rate neglect)
Базовая ставка · Базовый процент · Base-rate neglect
The background frequency of something across the relevant population - and the chronic mistake of ignoring it in favour of vivid specifics.
Specific stories beat statistics in System 1, even when the statistic is doing the actual work. A vivid description of a person who «sounds like a librarian» feels more diagnostic than the fact that there are 30 times more salespeople than librarians.
Forecasting, hiring, investing, medical testing - all routinely break because the obvious base rate gets dropped in favour of a striking case.
Most software projects miss their deadline by 50%+. Your team's plan says 8 weeks. The vivid plan beats the base rate - until reality reasserts it.
- 1Before estimating, find the base rate. Just one number from the reference class.
- 2Start from the base rate. Only adjust away from it when you have a SPECIFIC, defensible reason this case is different.
This part of the knowledge base is inspired by the book. Go to the Ukrainian edition to explore the concept in depth.
- · Методичка по Канеману - базовая ставка