Originally a 2009 Teach For America Mississippi Delta Corps Member, I am now a fourth-year teacher of low-income and minority students at a public charter high school in Crown Heights, Brooklyn. I would not be a teacher today without the support of TFA, and the majority of my incredible colleagues are Teach For America alumni. My principal—the most effective school leader I have ever witnessed as a teacher or a student—is a TFA alumnus.

But February 15 marks the final deadline to apply to be a 2013 TFA Corps Member, and you should not click “submit.”

Unfortunately, many TFA alumni (including myself) allow sentimentality to blind us to the harsh practicalities of TFA and its place in the education reform movement. The truth is, TFA teachers within their two-year corps commitment window do not, by and large, have tangible positive impacts on their classrooms. The natural extension is that if you join TFA, you will most likely have a neutral or negative impact on the academic gains of the students that you teach.

TFA paints a rosy picture for its prospective applicants when it glows that TFA corps members enable “students in high-need communities [to] make the academic progress that expands their opportunities.” But this statement isn’t bolstered by fact. TFA is not a traditional teacher-education program. In lieu of obtaining extensive preparation in multi-year undergraduate teacher credentialing programs, TFA corps members complete a five-week training program called “institute” in the summer immediately before they begin teaching. One study on the subject has shown that when compared a relatable cohort, teachers in the same schools who are untraditionally prepared and less likely to be certified, novice TFA teachers perform equivalently—but not superior—to those colleagues.

This seems disappointing but not terrible. You might not be the next Jaime Escalante (Stand and Deliver, anyone?), but surely you’re not going to de-learn your students as a first-year corps member, right?

Not so fast. Compare the performance of Teach For America corps members to another cohort: credentialed, non-TFA corps members. The same study indicates that novice TFA teachers actually perform significantly less well in reading and math than credentialed beginning teachers at the same schools. Keep in mind that to “perform significantly less well” as a teacher is quite literally to have a group of 10, 100, or even 200 students learn less than they would had you not been their teacher.

A professed mission of Teach For America when it was founded was to “provide an excellent education for kids in low-income communities,” especially in classrooms staffed by permanent or non-permanent substitutes and “emergency hires.” (My own students’ Algebra I teacher died in the fall before I came, and the students did not see a licensed or credentialed teacher for the rest of the year. Every child was passed on to geometry, yet 91 percent of them failed a low-rigor state Algebra I assessment.) In situations like that, a TFA teacher can be an injection of energy into a “failing” school. In those schools, TFA teachers are no more inadequate than their alternative, and the chance that these corps members might stay past two years and develop into strong teachers is small but worth taking. Unfortunately, these scenarios are becoming less and less frequent.

According to the study, TFA has been placing teachers outside of those roles that cannot be filled by certified or experienced candidates, in positions that could be filled (or in some cases, were previously filled until rounds of layoffs) by effective, veteran teachers. Although an initial skim of data released by the U.S. Department of Education reveals a large number of regions suffering from teacher shortages, a closer look reveals that TFA placements are “largely outside” of those highest-need areas. Therefore, the fact that TFA teachers are equally or more effective than their unqualified colleagues becomes irrelevant as we realize that the teachers who were once the inadequate alternative are, in fact, no longer the alternative at all.

There is some limited statistical evidence that TFA can be at least marginally impactful. But so few TFA teachers stay in the classroom beyond three years (more than 50 percent leave after two years and more than 80 percent leave after three), that the potential positive impact of TFA is rarely felt by the people who matter most—the students. In short, TFA may be pumping alumni who “understand” the achievement gap firsthand into various professions and fields outside of direct instruction, but it is doing so at the academic expense of the highest-risk kids who have the greatest need for effective teachers

If you feel inspired to teach, I beg you: teach! There are young people who need “lifers” committed to powering through the inevitable first three years of being terrible at teaching sinusoidal curves to hormonal 17 year-olds. I encourage you to pursue an alternative route to licensure and placement: one that encourages and actively supports longevity in the classroom and does not facilitate teacher turnover by encouraging its alumni to move into policy or other professions. If you feel compelled to Teach For America instead of teaching for America, please preference a region that has demonstrated a high need for novice teachers due to verifiable teacher shortages. And then stay in the classroom. For a long time. Feel at home teaching, and feel even more at home learning how to get better. Sit. Stay a while. Then stand and deliver.

Emma M. Lind '09, an editorial chair emeritus, is a public charter high school teacher in Brooklyn, New York.