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I last studied this stuff 20 years ago. What's the difference between ommitted variable and a confounding variable? Seems like a similar idea. Is it that an om
by monoideism 6y ago
I last studied this stuff 20 years ago. What's the difference between ommitted variable and a confounding variable? Seems like a similar idea.
Is it that an ommitted variable isn't part of a causal chain of an included variable, and a confounder is?
- rmrfstar 6y agoConfounding variable is a more confusing, less precise name for the same phenomenon. Omitted variable bias tells it like it is. A bias in a regression coefficient that results from an incorrectly specified model.
- monoideism 6y agoThanks. Assuming they refer to the exact same phenomenon, I agree that ommitted variable bias is better terminology. I wonder why Wikipedia has separate entries for them: https://en.wikipedia.org/wiki/Omitted-variable_bias https://en.wikipedia.org/wiki/Omitted-variable_bias https://en.wikipedia.org/wiki/Confounding https://en.wikipedia.org/wiki/Confounding
- rmrfstar 6y agoContext. The picture at the top of the confounding article gives it away. Those kinds of diagrams are common in "hierarchical Bayesian models" like LDA. In the simple linear setting, they are the same thing. Teaching people the "confounding variable" concept in a general setting before teaching them about "omitted variable" in a linear setting is like teaching people about Riemannian manifolds before teaching them about vector spaces. Correlation isn't a particularly useful concept outside of simple linear models.