Chicken or Egg?
It's a question nearly as old as time itself, dating back at least to Aristotle. " Which came first, the chicken or the egg? " Individuals representing different disciplines have arrived at different answers, or no answer at all. I've been thinking about this ancient question lately, and not for the reasons you might think. It would be easy to link this question to questions of causation that many readers of this blog grapple in their empirical research. Does the egg cause the chicken to exist, or does the chicken cause the egg to exist. I'm sure if Paul is reading this -- you know which Paul -- his mind is immediately going to what the DAG looks like and, I imagine, concluding that it is not acyclic . Anyway, I digress. This post is not about causation per se . This is about an issue in empirical work that rears its "ugly" head far too often, under different guises, different motivations, different descriptions. But, nonetheless, fundamentally repre