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> Anything that is less than double-blind is essentially a well documented hunch. Not true! Economists have devoted person-millenia developing the theory of in
by Jeff_Brown 3y ago
> Anything that is less than double-blind is essentially a well documented hunch.
Not true! Economists have devoted person-millenia developing the theory of instrumental variables, which lets you extract causal relationships from historical non-experimental data.
That said, it's damn hard to find a good instrument. Many economists use it badly, and most doctors don't even know the theory.
- htag 3y agoI have my doubts about IVs in practice, but I agree they theoretically are an acceptable substitute. The problem is we conduct science on systems we don't fully understand. Because we don't fully understand it, it's easy to miss important information we didn't know is important. The double blind with random selection allows us to control for all important information, determine causation, and is the best known method for controlling for bias. We don't have to worry about missing important variables because the nature of random selection means those variables are randomly distributed.
- Jeff_Brown 3y agoWhen possible, experiments are better, yes. But that should not cause us to give up hope for causal information in areas where experiments are impossible.
- monkeyjoe 3y agoEven subject level fixed effects would have made this a much better study. Doesn’t need to go all the way to IV to be a thoughtful design.