While there are no surveys determining the percentage of schools nationally that have instituted pay-to-play, what they charge, and the effect on student participation, plenty of information is coming out that the percentage is higher, the amount they charge varies wildly depending upon perceived budgetary needs, and whatever is charged, it is driving down student athletic participation.
Instead, it is the single most important budgetary variable because it affects the size of the tax base and the amount of government spending linked to the level of employment.