Erin Gavin, a Teach for America instructor, teaches a seventh-grade class in Brooklyn Center, Minn. (AP/Andy King)

Teach for America, the well known program that recruits college kids for teaching gigs in disadvantaged schools around the country, said recently that it had experienced a sudden decline in applications for this school year. And the program has received fewer applications for the next school year than it had at this point a year ago, after many years of rapid expansion since the program began in 1990. The decline is once again raising questions about the program's model, which has always been controversial.

The program's critics say it doesn't train its recruits adequately. They say that since Teach for America recruits only commits teachers to two years of teaching, it undermines the idea that teaching is a profession and a career. Proponents say pupils who are assigned to Teach for America staff perform better on standardized tests than their peers, and Teach for America has recently made changes in responses to claims that it puts naïve -- if intelligent -- college graduates in front of children whose great educational disadvantages they aren't prepared to address.

In 2013, Teach for America experienced a high number of applicants, but that was due to the program's efforts to persuade older people with experience in other professions to give teaching a try, according to a Teach for America representative. The number of applications declined by 12 percent the following year, and as of last month, there have been 10 percent fewer applications to teach in the next school year than there were last year, although the final deadline hasn't yet passed.  The decline in applications was primarily among college students. Whether that decline is only temporary, or whether it shows that the group has reached some kind of limit, remains to be seen.

In The New York Times, Motoko Rich suggests that Teach for America's bad reputation may be driving away some recruits. She spoke with Haleigh Duncan, a junior at Macalester College who considered applying:

As she learned more about the organization, Ms. Duncan lost faith in its short training and grew skeptical of its ties to certain donors, including the Walton Family Foundation, a philanthropic group governed by the family that founded Walmart. She decided she needed to go to a teachers' college after graduation. "I had a little too much confidence in my ability to override my lack of experience through sheer good will," she said.

An internal survey found that criticism of Teach for America was a factor that influenced 70 percent of candidates who ultimately chose not to apply, according to a comprehensive report by Bellwether Education Partners, a consulting firm.

Criticism of the group is not new, however. Teach for America may indeed have difficulty continuing to expand its workforce in the coming years -- but for economic reasons that have nothing to do with changing perceptions of the organization.

Interest in Teach for America increased rapidly during the financial crisis and the following recession, as many school districts were laying off staff en masse. Teach for America, with its two-year commitment, likely was an attractive option to prospective teachers unsure of whether it would be wise to invest their time and money in earning a conventional teaching credential, given the weak labor market.

"If you were somebody who wanted a career as a teacher, it didn't make a ton of sense to go to an education school in the last couple years, because their graduates weren't getting jobs," said Jesse Rothstein, an economist at the University of California, Berkeley, and expert on education.

Federal data show a 12 percent decrease nationwide in the number of prospective educators enrolled in teacher preparation programs between the academic year beginning in 2008, during the crisis, and the year beginning in 2011. In California, enrollments declined by nearly half.

But now, as the economy improves and headlines about layoffs in school districts become less frequent, Teach for America may increasingly lose this aspect of its appeal. The organization says that the decline in applications is mainly among those who apply without any previous contact with a recruiter for the organization, which suggests the economy might be a factor. Those who already know they want to go into teaching might be looking for other work, while there may be fewer students who can't find a job and apply because they don't know what else to do.

And aside from the recession, there is probably another reason the program will not be able to continue to expand. There are only so many students at elite colleges who are interested in teaching.

Richard Ingersoll, an economist at the University of Pennsylvania, and other scholars have conducted research showing that college students who go into teaching typically have lower SAT scores than average.

"Teaching has never been able to attract the best and brightest, and it's very obvious why," Ingersoll said. "Those with options are going to often choose more respected, better paid lines of work."

Teach for America's chief executive officers, Matthew Kramer and Elisa Villanueva Beard, made a similar point in a blog post on their Web site.

"Persuading young Americans to choose this work is tougher than ever," they wrote. "In the shadow of the recession, college graduates are moving away from public and service-oriented work and gravitating towards professions they perceive as more stable and financially sustainable."

Teach for America may be able to draw a few of those highly qualified young people into the profession. A recent government survey found that around 96,300 teachers nationwide had joined the past two years. With around 10,000 teachers in classrooms at any time, Teach for America's contribution to that figure is substantial. Still, poor pay is likely driving away some of the most able prospective teachers, a fact that Teach for America on its own cannot be expected to change.