"They have kids, a yard, live in the suburbs... probably 80% chance they have a dog!"
Better Approach
Start with Base Rate
"First, what % of Americans own dogs? Then I'll adjust based on these details."
The Base Rate
0%
of U.S. households own a dog
Source: American Pet Products Association, 2023
This is your starting point
Before looking at any details about the Johnsons, you already know there's roughly a 45% chance any random American family owns a dog. This is your anchor.
Adjust from Base Rate
🧠 Calibrated Thinking
📊Start with U.S. base rate45%
🏠Homeowners more likely to have dogs+8%
👧Families with kids slightly more likely+5%
🌳Suburban location is average+0%
🚗SUV is weak signal+2%
45%
0%Calibrated estimate100%
The Lesson
Base Rates First
From "Superforecasters" by Philip Tetlock
❌ Inside View
"80% chance"
Jumped straight to details. Overconfident. Ignored that most families don't have dogs.
✓ Outside View
"60% chance"
Started with 45% base rate. Made modest adjustments. More calibrated.
Superforecaster's Rule
Before asking "what's special about this case?", always ask "what usually happens in cases like this?" The base rate is your anchor. Details are adjustments—usually smaller than you think.