Diminishing Diminishing Returns

(Paul Jacob/Common Sense) – In late September, President Obama announced a goal. Noting that American students average out in the middle of the pack, vis-a-vis students worldwide, in science, technology, engineering, and math (STEM), he pledged to recruit 10,000 STEM teachers over the next two years.

This was put in proper context by Andrew J. Coulson, on a Cato website. He displayed two graphs. One compared employment rates versus enrollment rates in public schools. The enrollment rates have slightly risen since 1970, while the employment rate has skyrocketed. In the other graph, the inflation-adjusted cost of a K-12 education contrasts with achievement scores for reading, math, and science during the same period. The costs skyrocketed, while the test scores had barely moved.

Perhaps students should be encouraged to apply a little math to this.

From economics we have the concept of diminishing returns. For each expenditure of input, smaller increases are expected of output. So, if we’ve been increasing teachers and administrators during this period, but the scores have neither diminished nor increased, this suggests a number of things, chief being that, well, expenditure of funds on public schooling is not the chief variable in improving knowledge or achievement. Not now, anyway.

So why would we increase expenditures?

Could the expected returns be political rather than academic? Could President Obama care more about teacher union support, say, than what kids actually learn?

Far be it for me to suggest this. Let the data alone do that.