A quick math lesson for North Carolina: Per-pupil spending has no effect on school quality

These two charts show there's no link between spending and school performance

There’s a general consensus in North Carolina politics that our education system is in dire need of improvement. For Gov. Roy Cooper, and Democrats in general, the answer to this problem is simple: spend more money.

In their view, more per-pupil spending is the key that will unlock better schools and higher performance for students. It’s a politically popular approach, but it just doesn’t work.

Around the country, there’s simply no link between spending and school performance.

Here’s the evidence, in two charts.

First, I compared each state’s per-pupil spending with fourth-grade performance on the most recent National Assessment of Educational Progress exams, also known as the government’s “Nation’s Report Card.” This is an exam that every student in the country takes, making it easy to compare performance from state to state.

If more spending resulted in better quality, you’d see a sharp down and to the right trendline. Instead, the results show a statistically insignificant link between per-pupil spending and reading performance.

You can dive into the underlying data here.

Now granted, fourth-grade NAEP reading scores are a blunt tool that leaves a lot out. Performance measures, in general, don’t capture how well schools are helping students improve. They also don’t necessarily represent the entire K-12 system. For example, Florida performs exceptionally well on this measure but has a lower ranking in later grades.

So I also compared per-pupil spending with a “learning rate” metric from Stanford University that seeks to measure how student test scores improve over time. The researchers bill it as an indicator of school effectiveness. And here, that slight-but-insignificant link between per-pupil spending and school quality completely goes away. There is zero correlation at all.

You can dive into the data here.