Developed by Robert Stalnaker (A Theory of Conditionals, 1968), David Lewis (Counterfactuals, 1973), and Judea Pearl (Causality, 2000).
Tests whether something caused an outcome by changing that one factor in an imagined version of events and tracing what would have followed.
When to reach for it
Reviews that must judge whether a campaign, decision, or event really produced the result, or whether it would have happened anyway.
How it runs
- Pick the outcome to explain.
- Pick one candidate cause to test.
- Imagine the smallest change that removes it, keeping all else equal.
- Trace forward what would have happened instead.
- Compare that outcome with the actual one.
- Try nearby alternatives to see how sensitive the answer is.
Where it sits in SOLVE eX
Go to the source
- A Theory of Conditionals, Studies in Logical Theory, 1968
- Counterfactuals, 1973
- Causality: Models, Reasoning, and Inference, 2000