If a larger share of the population is currently enrolled in public schools, there will be a larger number of prospective beneficiaries of higher public school spending. That, in turn, may change taxpayers’ desire for or acceptance of higher spending independently of how much they might value education in the abstract (which is already controlled for with the average income term discussed above).

To capture this measure of the public’s vested interest in public school spending, census data on public school enrollment as a share of total district population is included as a control variable.[11]