Leaving Oklahoma isn’t what he wants to do, but he and his wife, both public school teachers, can’t afford to stay.

In Texas, Sheehan will make $20,000 more than he did in Oklahoma, a state where some schools are open only four days a week and lawmakers are asking the education department to make more cuts. Class sizes are large, resources are scarce, and math teachers like Sheehan are being replaced by people with emergency certificates. Support staff have been let go, textbooks are out of date, and electives such as art and music have been eliminated. 

In a recent interview with NPR, Sheehan expressed regret that he is having to leave.

“It feels good because I know I’m doing the right thing for my family,” he said, “but I feel sad because, you know, I thought that I would retire teaching out of this classroom.”

In addition to leaving for higher-paying teaching jobs, talented teachers often leave the classroom to become school administrators. Administration jobs pay higher salaries and offer the only real promotions in education.

A case in point is Spencer Campbell, a former small business owner who went back to college to get certified in secondary education and spent five happy years teaching in Utah. Even with an extra part time job, Campbell had trouble making ends meet on his teacher’s salary. When a position for an assistant principal came open in a nearby middle school, he took it despite his sadness about leaving his students.

“The effect that a classroom teacher has on a student is second only to a parent,” Campbell told NPR. “And as an administrator, I don’t know if I’ll ever be able to have that same effect and that’s kind of heartbreaking.”

The loss of classroom teachers isn’t going to slow down anytime soon. With an overall teacher turnover rate more than 14 percent in North Carolina and a turnover rate twice that in some of the poorer, rural districts in South Carolina, the churn will hurt students.

This summer, school districts nationwide are scrambling to fill teacher shortages and prepare for the coming school year. The U.S. Department of Education has tracked shortages since 1990 through the most recent school year, and every state has multiple areas where classrooms are hard or impossible to fill. This is particularly true in rural or poor districts where salaries are the lowest.

Nor are the teachers to fill those positions currently being recruited and trained. The Learning Policy Institute estimates that enrollment in teacher-preparation programs dropped 35 percent from 2009 to 2014.

That’s not a surprise. When someone with a college education can find a job that pays more, offers more autonomy and respect, and has opportunities for professional development and advancement, why should she consider a career as a teacher?

Of course the rewards of working with students are tremendous. That’s why so many teachers sacrifice good salaries, retirements, and benefits to be in the classroom.

But they shouldn’t have to.

Until we decide to invest in professional pay and working conditions for teachers, we are going to see Teachers of the Year leave for greener pastures, talented teachers abandon their classrooms for jobs as administrators, and far too many teachers walk away from the profession.