3 ms·
>Controlling for a collider leads to correlation This is a big one that most people are not aware of. Quite often, in economics, medicine, and epidemiology, yo
by levocardia 2y ago
>Controlling for a collider leads to correlation
This is a big one that most people are not aware of. Quite often, in economics, medicine, and epidemiology, you'll see researchers adjust for everything in their regression model: income, physical activity, education, alcohol consumption, BMI, ... without realizing that they could easily be inducing collider bias.
A much better, but rare, approach is to sit down with some subject matter experts and draft up a DAG - directed acyclic graph - that makes your assumptions about the causal structure of the problem explicit. Then determine what needs to be adjusted for in order to get a causal estimate of the effect. When you're explicit about your causal assumptions, it makes it easier for other researchers to propose different causal structures, and see if your results still hold up under alternative causal structures.
The DAGitty tool [1] has some cool examples.
[1] https://www.dagitty.net/dags.html https://www.dagitty.net/dags.html
- kyllo 2y agoCollider bias or "Berkson's Paradox" is a fun one, there lots of examples of it in everyday life: https://en.wikipedia.org/wiki/Berkson%27s_paradox https://en.wikipedia.org/wiki/Berkson%27s_paradox