Good teachers make a difference.

That hardly qualifies as news. But combined with a serious statistical analysis of how much difference the best teachers can make in the future earnings capacity of their students, that simple declarative sentence gains a certain gravitas.

The New York Times reported on such a study, conducted by Harvard economics professors Raj Chetty and John N. Friedman and Columbia University’s Jonah E. Rockoff. The scientists tracked 2.5 million elementary and middle-school students over 20 years and found convincing statistical evidence that replacing just one poor teacher with an average one could raise an entire classroom’s earnings capacity by $266,000 over their lifetimes.

The study went so far as to suggest that other risk factors facing teenagers, such as pregnancy, also were reduced by the presence of good teachers.

The report reinforces the incredibly important that role teachers play in our children’s future.

Richard Barth, the CEO of the nationally acclaimed nonprofit KIPP charter schools, says that the key to turning around underperforming urban school districts is to "flood them with human capital."

That means finding good principals and teachers and putting them in an environment in which they can succeed.

Having one top teacher for one year can raise a student’s lifetime earnings by $9,000, the Harvard study concluded. Do the math and think what top teachers every year could mean.

It’s a formula for success.