The cost of public education

A friend has re-posted some charts from a CATO Institute article on costs associated with public education. As you can probably guess, the article has a particular point it's trying to make; I'd like to point out some things that might be helpful before you read it.

The article refers to data collected from the NCES 2009 Digest. When you notice that the number of public school employees is growing at a faster pace than the number of enrolled students, it would be helpful to know the breakdown in the increase of employees - how many are teachers, staff, administrators, etc. That's available in this table from the National Center on Education Statistics (NCES) which shows that at least between 1990 and 2007 teacher salaries represent a pretty constant 61% of expenditures. Other subgroups (administration, staff, food services, transportation, etc.) keep pretty constant ratios as well.

How does this compare to private/religious school staffing at the same level? You can actually test that with this table, which shows that the number of teachers in the public sector rose 50% between 1980 and 2009 - but so did the number of teachers in private schools. The number of students has increased by roughly 26%. The net effect has been to drive down student/teacher ratios from 18.7 to 15.3 in the public sector; in the private sector the ratio went from 17.7 to 12.8.

On the bottom chart in the CATO article: As the source says: "Total expenditures for public elementary and secondary schools include current expenditures, interest on school debt, and capital outlays." Capital outlays include new technology, internet access, textbooks and materials, laboratories, school buildings, etc. Schools would, for example, save a huge amount of money by replacing obsolete Windows and Macintosh computers with state-of-the-art Linux machines. Table 182 confirms the graph; expenditures per pupil doubled from 1980 ($5695/student) to 2009 ($10,041/student).

But compare that to private schools: table 27 shows an increase in overall private school expenditures (in constant dollars) of 150% between 1980 (est. $20B) and 2009 (est. $50B). That compares to the public schools which increased 130% over that period, from $262B to $600B.

Does the increase in costs raise scores? chart 123 shows the scores stay pretty constant from 1992 through 2007. The overall scores for private schools are higher per grade; but that may be an effect of a self-selecting population. More interesting are the jumps from 4th to 8th grades (keeping in mind these are comparing apples to oranges to some extent, as students move around). Public schools increase the scores by 50 points over 4 years (a 1994 4th grader to a 1998 8th grader), and so do the private schools. As a percentage, the public schools raise scores 25% over the 4 years, while private schools raise them a little over 20%. That's an interesting result given the popularity of the new "value added" calculations used to assess teachers and schools.

Moving students from public schools to private schools would apparently increase the number of teachers required to maintain their low student/teacher ratio. How will that drive down the cost of education, other than by paying teachers individually less? Would increasing private school costs and lowering public school costs reduce the price of education overall - or would it instead shift the cost more directly to parents and reduce the cost to taxpayers without children? It would be a policy decision to decide if that's equitable - spreading what would essentially be the same cost over a smaller group of people.