The graph below was recently posted by U.S. Education Department (USED) Secretary Betsy DeVos, as part of her response to the newly released scores on the 2017 National Assessment of Educational Progress (NAEP), administered every two years and often called the “nation’s report card.” It seems to show a massive increase in per-pupil education spending, along with a concurrent flat trend in scores on the fourth grade reading version of NAEP. The intended message is that spending more money won’t improve testing outcomes. Or, in the more common phrasing these days, "we can't spend our way out of this problem."
Some of us call it “The Graph.” Versions of it have been used before. And it’s the kind of graph that doesn’t need to be discredited, because it discredits itself. So, why am I bothering to write about it? The short answer is that I might be unspeakably naïve. But we’ll get back to that in a minute.
First, let’s very quickly run through the graph. In terms of how it presents the data, it is horrible practice. The double y-axes, with spending on the left and NAEP scores on the right, are a textbook example of what you might call motivated scaling (and that's being polite). The NAEP scores plotted range from a minimum of 213 in 2000 to a maximum of 222 in 2017, but the graph inexplicably extends all the way up to 275. In contrast, the spending scale extends from just below the minimum observation ($6,000) to just above the maximum ($12,000). In other words, the graph is deliberately scaled to produce the desired visual effect (increasing spending, flat scores). One could very easily rescale the graph to produce the opposite.