When Does Inexact Matching Ensure Balance and Inference without Adjustment?
非精确匹配何时能在无需调整的情况下保证平衡与有效推断?
One-to-one matching without replacement is a classical approach to constructing comparable treated and control samples in the design of observational studies. It pairs each treated unit with a distinct control while minimizing a covariate distance objective. With continuous covariates, the matched pairs generally remain inexact, which contributes to bias in downstream analysis. Its key theoretical properties, such as the resulting imbalance between matched pairs and when it…