It’s July. What is the typical public-school teacher doing right now? According to The Atlantic, she is probably hard at work.

Last week The Atlantic published an article by Liz Riggs provocatively titled, “The Myth of a Teacher’s ‘Summer Vacation.’” The piece is more balanced than the title implies, but its presentation of the debate is unsatisfactory. To summarize, teacher contracts require only 190 days or so of work, but teachers work more than their contracts stipulate. In the summer, they are “attending meetings, developing school curriculum, helping train new teachers, and contacting families of [their] students, among other tasks.” Then there is “graduate-school coursework . . . classroom organization or relocation, and so on.”

That is where the debate seems to end, based on the Atlantic article. Whether those summer responsibilities amount to full-time work is left up in the air, but the implication is that summer vacation should not really be considered a perk of teaching.

That implication is wrong. I know that because we actually have data that measure teacher work time as definitively as anyone could hope for. The American Time Use Survey (ATUS) creates a “time diary” for respondents that describe their activities during the entire 24-hour day before their interviews. Those activities include work wherever and whenever it occurs. The ATUS does not undercount working at home versus working at an office, or working evenings rather than working regular business hours. If, for example, an individual was working at 2 a.m. at home on the weekend, the ATUS will still catch it.

Using the ATUS, Andrew Biggs and I found that public-school teachers worked roughly 250 hours — the equivalent of a little more than six 40-hour weeks — over the months of June, July, and August. By contrast, other white-collar professionals worked about 13 weeks over the same time period. So teachers do enjoy, on average, a substantial summer vacation.

Over the course of the full calendar year, we found that public-school teachers work about 83 percent as much as other white-collar professionals. This does not mean that teachers lack commitment or dedication. It does mean that the lower number of work hours must be taken into account when comparing the compensation of teachers and non-teachers.