After checking and rechecking their analyses, Staiger and Rockoff came to understand why a thick stack of pink slips are needed to improve schools. There are enormous costs to having mediocre teachers burdening the school system, and once they get their union cards, we're stuck with them for decades. The benefits of keeping only the superstars is enormous, such that it's better to risk accidentally losing some of the good ones than to have deadwood sticking around forever.
Is an 80 percent dismissal rate practical? One issue is whether there would be enough new recruits to replace all the teachers you'd be firing. Teach for America has been able to fill its ranks with Ivy League graduates year after year, so we know there are lots of college grads who are willing to devote at least a couple of years of their lives to teaching, and 63 percent of TFA alumni remain in the field of education afterward. If the teaching profession gains greater status and prestige, perhaps many more would choose teaching as a career rather than moving on to more lucrative jobs at Goldman Sachs or McKinsey. And in 1997, the L.A. school system was able to triple its rate of hiring, bringing in additional recruits with no discernible decline in the quality of those hired. Then again, while TFA and the L.A. Department of Education may have a steady supply of applicants, that doesn't much help schools in small-town America, where recruitment is more of a challenge.
And, of course, another issue is politics. It's hard to reconcile an 80 percent dismissal rate with the existence of teachers' unions: Pushback from unions and the government leaders who rely on their support have largely managed to prevent any breach of teacher job security thus far. (Although, D.C. Schools Chancellor Michelle Rhee may be on her way to cutting a tenure-ending deal with Washington's union.)
This is something that Staiger and Rockoff understand. Their point isn't that we can or should fire 80 percent of new hires, but that their work should be seen as a "thought experiment" on the extreme measures that would be required to really improve American education, provided we can't figure out how to find better teachers at the get-go or develop reliable methods of improving teachers once they're in the system.
There is a glimmer of hope, though, if we can learn to emulate a handful of small-scale school systems that seem to have had success making great teachers, either by picking stars or creating them. Students randomized into New York's (oversubscribed) charter schools outperform students who applied to these schools but drew low lottery numbers and were forced to attend public schools instead. The cumulative benefit of attending a New York City charter school is sufficiently large as to almost erase the math performance gap between low-income kids in Harlem and those in affluent suburbs by the time kids get to the eighth grade. Better teachers are surely part (but not all) of the explanation for this success. The charter schools have high teacher turnover but also have reputations for nurturing talent and improving classroom performance: They videotape rookie teachers; coach them intensively on pedagogy; focus relentlessly on results. It's painful, and it's hard work—hence the high turnover.
Uncommon Schools is one of these superstar school systems, and one of its directors, John King, is now the head of K-12 education for New York State. Firing 80 percent of new teachers isn't possible in rural areas in the state and wouldn't play well in the State Legislature in Albany, either. Despite past failures, King remains optimistic: The government is giving out billions of dollars to fund education innovation through its Race to the Top fund, and methods of teacher preparation at places like Uncommon are being studied with an eye to integrating them into larger school systems. Hopefully the new knowledge and programs generated by these efforts will help King figure out how to scale up his successes from the couple of thousand students enrolled at Uncommon to the 2 million attending public schools statewide.