No doubt the timing was sheer coincidence. On the same day the red wave of teachers, children and allies rolled up Fayetteville Street, the U.S. Census Bureau released a data set that frames the rally in Raleigh in a national context.

“Where are our teachers going?” asks the headline on the short census paper on educators leaving the profession. The census issued national data, not specific state data, but relevant nonetheless to the issues of compensation and teaching conditions raised by the crowd that marched toward the Legislative Building.

The census paper reports that the teacher departure rate “is increasing steadily and shows no sign of slowing down.” Departing teachers tend to shift to jobs in health care, social assistance and administrative services.

“Educators between the ages of 25-34 are the vast majority of job-to-job movers,” says the census. Its chart shows more males than females in departing teachers.

In North Carolina as elsewhere, much of the teacher turnover involves moves from one school to another. In its statistical update released last month, Best NC, a nonprofit organization of business leaders focused on education policy, put the state average turnover rate at 13.5 percent in the 2016-17 school year. It reported that 4,549 teachers moved to another school, compared to 767 who went to teach in another state and 865 who made a career change.

Meanwhile enrollment in teacher education in the UNC system declined annually from 2010 to 2015, with a slight uptick in 2016. And, as Best NC documents, school systems report difficulty in staffing math, science and special education. “One-third of middle and high school math and science courses are taught by teachers without licenses in the discipline they are teaching,’’ says the Best NC report.

The census paper provides a link to an earlier Learning Policy Institute brief on teacher turnover — and the brief is in turn linked to an array of reports on teacher supply, demand and shortages. In 2017, says the brief, “more than 100,000 classrooms across the country (were) staffed by an instructor who is not fully qualified to teach.”

The institute reports turnover rates are higher in the South, and lower in states that offer higher pay, smaller class sizes and overall greater investments in schools. These are among the issues raised by the teacher-marchers — issues that not only affect them personally but also are key factors in raising student achievement in the years ahead.

“Addressing early attrition is critical to stemming the country’s continuing teacher shortage crisis,’’ says the Learning Policy Institute brief. “It is also important for school effectiveness. The cost of attrition to student learning and district budgets is significant. Teachers are the number one in-school influence on student achievement. Research finds that high rates of turnover harm student achievement.”

The institute brief says turnover rates are 50 percent higher in schools with large enrollment of low-income students — and fully 70 percent higher in schools “serving the largest concentrations of students of color.”

“To stem teacher turnover,” says the institute, “federal, state, and district policymakers should consider improving the key factors associated with turnover: compensation, teacher preparation and support, and teaching conditions.”

In today’s fractious, polarized public square, it seems inevitable that a galvanizing event such as the teachers’ march, carried live on TV stations, would set loose a bit of political jousting. Still, democratic politics is energized both by citizens exercising their right to petition their government and by data-informed policymaking.

Ferrel Guillory is the director of the Program on Public Life, professor of the Practice at the UNC School of Media and Journalism, and the vice chairman of EducationNC.