Written By: Qingyang Xu (website)
Date Created: July 6, 2022
Last Modified: October 1, 2023
Causal Inference with Applications
- Summary of the Harvard course STATS 286 taught by Professor Imai
1. Potential Outcomes
Setup
- Treatment $T_i$ (e.g., whether voter $i$ is canvassed)
- Outcome $Y_i$
- Pre-treatment covariates $X_i$
- Causal effect for voter i: $\tau_i=Y_i(1)-Y_i(0)$
Key Assumptions
- Causal ordering: $T_i \rightarrow Y_i$
- Consistency: $Y_i = Y_i (t)$ whenever $T_i = t$
- No hidden multiple versions of treatment
- No hidden different administration of treatment
- No interference between units: $Y_i (T_1, \cdots , T_n) = Y_i(T_i)$