indigo, I get that correlation does not imply causation.
Instead, families interested in education move to towns with strong school systems. It is a conscious self-selection process because these towns have higher costs relative to otherwise similar towns with lesser school systems.
The parents in turn support the school system through higher taxes relative to other towns, and hold the school system accountable for high standards. Teachers are selected based upon quality, and teachers partially self-select themselves because good teachers love good students.
Students compete against each other, making everyone stronger. Parents and students see the older students perform exceptionally and know that the same might be possible for their children, given the right talent, effort, and coaching. Exceptional local teachers or former teachers offer high-level coaching outside of school, and there is ample demand for it.
In short, a strong school system becomes the center of a self-reinforcing ecosystem of high performance.
