Incrementality
Overview
Section titled “Overview”Incrementality isolates causal impact from confounders using experiments or quasi-experimental designs.
Key principles
Section titled “Key principles”- Counterfactual thinking: compare against what would have happened otherwise.
- Randomization preferred; alternatives include diff-in-diff, synthetic control.
- Guard against selection bias and seasonality.
Quality checks
Section titled “Quality checks”- Pre-trend parity; stable units and no spillovers.
- Sensitivity analyses and robustness checks.
Common pitfalls
Section titled “Common pitfalls”- Attribution bias and double counting.
- Naive before/after analyses.
When to use / not to
Section titled “When to use / not to”Use when you need causal truth for budget and strategy. Not for quick directional checks.