Selection of Identifiability Criteria for Total Effects by using Path Diagrams

TL;DR

This paper compares three identifiability criteria for total effects in causal diagrams, analyzing their accuracy and applicability based on graph structures to guide better causal effect estimation.

Contribution

It provides a comparative analysis of back door, front door, and IV criteria for total effect identification using path diagrams, highlighting when each is preferable.

Findings

The superior criterion can be identified directly from the graph structure.

Comparison based on asymptotic variance shows differences in estimation accuracy.

Guidelines for choosing the best criterion in different situations are provided.

Abstract

Pearl has provided the back door criterion, the front door criterion and the conditional instrumental variable (IV) method as identifiability criteria for total effects. In some situations, these three criteria can be applied to identifying total effects simultaneously. For the purpose of increasing estimating accuracy, this paper compares the three ways of identifying total effects in terms of the asymptotic variance, and concludes that in some situations the superior of them can be recognized directly from the graph structure.