In 1974-75, California spent $1,373 per pupil on k-12 public schooling. By 2006-07, it was spending $10,937. Adjusting the earlier figure for inflation (to $5,286 in 2007 dollars), that still represents a more than doubling in real spending per pupil.
Of course, if California public schools had doubled student achievement and eliminated dropouts, that might justify their staggering increase in cost. They haven’t.
California is in budgetary hell because of a massive collapse in the productivity of its public schools. If the public schools had just maintained the productivity level they enjoyed in 1974-75, taxpayers would now be saving $36 billion annually.