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Mathematics

Causal Inference Using Instrumental Variables

Quick fact

Instrumental variables can uncover causal effects even when we cannot measure or control for all confounders, as long as a valid instrument exists—making them a cornerstone of 'natural experiments' in economics and epidemiology.

Why this is interesting

How can we prove that a new drug really works when we can't run a randomized trial? The answer may be hiding in an unlikely variable.