A recent Stanford/Duke University economic study found that the No. 1 factor leading to increased student success is our classroom teachers’ credentials.

In economic terms, that means quality teachers are our most precious resource regarding our educational tax-dollar return on investment. In other words, this is where we get the most bang for our buck.

Using the standard business calculation for turnover cost, each classroom teacher we lose to another school district or retirement costs us, at minimum, an additional $10,000 in training and other incidentals to replace that teacher.

That doesn’t include the unquantifiable wealth of experience that inevitably is lost to the other district. Good for them, bad for us. For the Mehlville School District, that means almost a half-million dollars in unfortunate but necessary expenditures each and every fiscal year.

Therefore, the most efficient and effective fiscal practice would be to keep both the money and credentialed classroom teachers at Mehlville.

Many of the images and perceptions we have of teachers stem from the 1950s. For better or worse, this world has changed since the ’50s, and it has changed exponentially in just the last decade and a half.

I don’t believe anyone has summed it up better than Thomas Friedman in his book “The World Is Flat: a Brief History of the 21st Century.” Friedman explains how his father used to tell him that he had better eat his dinner because the people in India and China are starving. Now he tells his daughters, “Girls finish your homework — people in China and India are starving for your jobs.”

Our classroom teachers today face a very different world than their 1950s counterparts.

Classroom teachers today are on the front line, doing whatever they can and working against all kinds of odds to produce generations of children who will be able to compete and find jobs in the new global economy. Who do you want on the front line?

Each community must decide that question, but my experience has shown me you get what you pay for.

Mehlville’s teachers are 100-percent fully qualified, meaning each one has a bachelor’s degree or better and state certification, among other credentials. So consider how our teachers are qualified, throw in the breadth of their responsibilities in today’s world and a clearer picture begins to take shape.

More and more special-needs children are attending our public schools, combined with an unprecedented escalation in autoimmune diseases, autism, et cetera. More than 10 percent of our students are classified as English Language Learners.

In some classes, as many as half of the students do not live in a home where English is the primary spoken language.

Today’s teacher typically works a 65-hour week. Besides classroom duties, teachers supervise extracurricular activities, coach, occasionally attend overnight class trips and clean and disinfect toys. We ask them to teach, to police and to provide emotional and social guidance. They teach fire-drill safety procedures and healthy eating habits. Many times, they are certified in cardiopulmonary resuscitation, first aid and food sanitation. Then they spend another 10 hours a month communicating with parents.

Our teachers are asked to do all of this in a society where incomes are not keeping up with inflation and a society requiring two full-time-incomes per home to successfully raise a family. We pay a starting salary of $32,000 per year — the same pay as a beginning employee at a convenience store.

And don’t forget that the amount of required and non-reimbursed continuing education necessary to remain a classroom teacher in the Mehlville School District is comparable to that of an architect, engineer or attorney — or that even with all of the supposed “days off and vacations,” teachers still average 46 hours per week in a 12-month period. Is it any wonder that half of all teachers quit the profession outright within five years?

Does it make sense for our district to pay a competitive wage and do what is necessary to retain our highly qualified teachers? The market says the answer is absolutely, positively, unequivocally yes.

Editor’s note: Mr. Frank serves as vice president of the Mehlville Board of Education.