[This is the second part of a fair copy of a recent Twitter thread of mine. I suggest you have a look at part 1 about nonlinear mediation analysis first. Otherwise, it might be hard to follow this post.]
Understanding causal effects is tough, but understanding causal mechanisms is even tougher. When we try to understand mechanisms we move beyond the question whether a certain causal effect exists, and ask how an effect comes about instead. Continue reading A plea for simple theories