Within this sample, years of education would be mostly fixed. Those with more/fewer would run into selection effects (e.g. getting held back a grade gets more years schooling, but presumably lower odds of getting into Oxford).
Suppose we were doing chemistry instead of schooling (so that I didn’t already know the answer).
I have two beakers, one labeled 6.01 and one labeled 6.99 and I then pour 12 units of “school” into each beaker. Afterwards I discover that the beaker labeled 6.99 has produced 2x as much “oxford” as the beaker labeled 6.01. The conclusion I would come to would not be that “school” is pretty good at producing “oxford”.
Even more fun, I challenge you to predict the amount of “oxford” produced by adding 12 units of “home school” instead of “school”.
Within this sample, years of education would be mostly fixed. Those with more/fewer would run into selection effects (e.g. getting held back a grade gets more years schooling, but presumably lower odds of getting into Oxford).
That’s exactly my point.
Suppose we were doing chemistry instead of schooling (so that I didn’t already know the answer).
I have two beakers, one labeled 6.01 and one labeled 6.99 and I then pour 12 units of “school” into each beaker. Afterwards I discover that the beaker labeled 6.99 has produced 2x as much “oxford” as the beaker labeled 6.01. The conclusion I would come to would not be that “school” is pretty good at producing “oxford”.
Even more fun, I challenge you to predict the amount of “oxford” produced by adding 12 units of “home school” instead of “school”.