Inexact Matching using Minimized Distance Metrics

Primer on nearest neighbor matching and robust standard errors with concrete examples of calculations

Fraternal twins, Michael and Ashton Kutcher.

Introduction

Matching estimation is possibly the most intuitive causal method outside of the RCT. The idea that if we want to estimate a causal effect, comparing people that look alike sort of just feels right to a lot of people. After all, if selection bias is a result of comparing groups that are super differ…