In the U.S. public education system, this assumption is dead wrong. There total expenditures are allocated from the top down to mop up available revenues. How much any public school spends depends not on how much it “needs” for efficient operation but on how much it can extract from taxpayers. These revenues are then dissipated among various squabbling constituencies to feed their continuous demand for public funds.
In the topsy-turvy world of public education, the incentive is for efficient, low-cost schools to imitate the less efficient, high-cost schools by spending more. The result is that U.S. public education is greatly over-funded. Public school per-pupil costs are roughly 40 to 45 percent higher than those of private schools. When we take into account the larger number of private elementary schools and further adjust for special ed, the difference narrows to about 36 percent.
And, might I add that private schools tend to be better at educating their their public counterparts? And, why am I paying to put my neighboors kids though this?