The average salary of a public schoolteacher in North Carolina was about $54,000 last year, up 20 percent since 2014. That was one of the largest increases in the nation. According to the latest data from the country’s largest teacher union, the National Education Association, our state’s average pay ranked 29th. Adjusted for cost of living, North Carolina ranked 20th.

These statements aren’t inconsistent with the propositions that North Carolina ought to spend more money on teachers, that North Carolina ought to spend more on education in general, or that the GOP-led General Assembly should have raised teacher pay even faster over the past five years than they did.

In other words, these facts don’t “speak for themselves.” Facts never do.

Because education is the largest category of state expenditure, the largest state enterprise in North Carolina, and integral to the values and aspirations of most North Carolinians, it has long dominated the political conversation. That won’t change. But perhaps, if we try hard enough, we can improve the quality of the conversation.

Consider the question of “average teacher pay.” Frustrated by how Republican lawmakers touted the latest NEA ranking, Democrats and progressives have argued that the statistic was misleading. Some of their points were silly and risible (of course lots of teachers make less than the average, except perhaps in the Lake Wobegone School District).

But another question critics asked was more reasonable. Do teachers really comparison-shop across the country to decide where to teach? Some may do so, especially right out of college or if they reside near a state border. But most teachers don’t. They compare the compensation they’ll make teaching in their state’s public schools to the compensation they’ll make doing something else (including the difference in working days per year). Or they move to a state for a different reason, such as accompanying a spouse, and then get teaching jobs.

Speaking of that term “compensation,” workers aren’t just paid with cash. They often place a high value on non-wage benefits. States differ in what they offer teachers as well as how credible those offers are in the long run — that is, how solvent their pension and health plans are. Without adjusting for benefits, we can’t really say how states rank in average teacher compensation.

Another consideration is average age. While North Carolina has moved away from rigidly basing pay scales on years of experience, thank goodness, there will always be somewhat of a relationship, just as there is in many other careers.

When school systems hire more teachers, either to keep up with enrollment growth or intentionally to reduce class sizes, the new hires are usually on the lower end of the scale. All other things being equal, that will tend to reduce average salaries even if no teacher makes less than before.

Mike Petrilli reported an interesting finding in a recent edition of the journal Education Next, where he is executive editor. Petrilli looked at changes in K-12 enrollment and per-pupil spending from 2000 to 2015. While there certainly were some outliers, in general the states with the fastest growth in student populations had the lowest growth in per-pupil expenditure.

Part of the explanation is that in places where enrollments are stagnant or declining, policymakers don’t precipitously lay off teachers or close schools. They maintain funding levels. Per-pupil expenditure rises. At the same time, when enrollments surge, states scramble to keep up — and typically prioritize hiring teachers over enhancing compensation. They spend lots more money but the increase per pupil isn’t as large.

I am persuaded by the evidence that policymakers should instead let the pupil-teacher ratio rise and boost salaries, particularly for the highest-performing teachers. The effects on student performance would likely be greater. Although it may be popular, class-size reduction is usually not the most cost-effective approach.

If we are ever to make the best use of resources devoted to education, we need to find a better, less accusatory way to talk about school spending.

John Hood (@JohnHoodNC) is chairman of the John Locke Foundation and appears on “NC SPIN,” broadcast statewide Fridays at 7:30 p.m. and Sundays at 12:30 p.m. on UNC-TV.