Just how much do our public schools spend per pupil to educate them?

More than you've been told, and more than you think.

P.J. O'Rourke is deadly serious:

In March the Cato Institute issued a report on the cost of public schools. Policy analyst Adam Schaeffer made a detailed examination of the budgets of 18 school districts in the five largest U.S. metro areas and the District of Columbia. He found that school districts were understating their per-pupil spending by between 23 and 90 percent. The school districts cried poor by excluding various categories of spending from their budgets-debt service, employee benefits, transportation costs, capital costs, and, presumably, those cans of aerosol spray used to give all public schools that special public school smell.

Schaeffer calculated that Los Angeles, which claims $19,000 per-pupil spending, actually spends $25,000. The New York metropolitan area admits to a per-pupil average of $18,700, but the true cost is about $26,900. The District of Columbia's per-pupil outlay is claimed to be $17,542. The real number is an astonishing $28,170-155 percent more than the average tuition at the famously pricey private academies of the capital region.

School districts also cheat by simple slowness in publishing their budgets. The $11,749 is from 2007, the most recent figure available. It's certainly grown. The Digest of Educational Statistics (read by Monday, there will be a quiz) says inflation-adjusted per-pupil spending increased by 49 percent from 1984 to 2004 and by more than 100 percent from 1970 to 2005.

The only question that matters is are parents getting their money's worth?

SAT scores in 1970 averaged 537 in reading and 512 in math, and 38 years later the scores were 502 and 515. (More kids are taking SATs, but the nitwit factor can be discounted-scores below 400 have decreased slightly.) American College Testing (ACT) composite scores have increased only slightly from 20.6 (out of 36) in 1990 to 21.1 in 2008. And the extraordinary expense of the D.C. public school system produced a 2007 class of eighth graders in which, according to the NAEP, 12 percent of the students were at or above proficiency in reading and 8 percent were at or above proficiency in math. Many of these young people are now entering the work force. Count your change in D.C.

Incredible.