Policy fixes are necessary to lay the groundwork for change, but it's in the implementation of those policies where the rubber meets the road.
Since 2009, a lot of states have made changes to their tenure laws, including New York. In that state, new policy changed what happens after new teachers complete the three-year probationary period, requiring school leaders to review the "candidate's effectiveness over the applicable probationary period in contributing to the successful academic performance of his or her students" before tenure is granted. Did that new law and its dogged implementation by Joel Klein, et al., in New York City make any difference?
Perhaps so. Research released by Susanna Loeb, Luke Miller and James Wyckoff found not only that the district currently awards tenure to far fewer teachers than it once did, but also that the quality of the overall teacher applicant pool showed a marked improvement: a struggling teacher who left the system after the district decided to delay its tenure decision was, on average, replaced by a measurably better teacher.
Interestingly, when the district told teachers it was not ready to make a tenure decision (delaying for a year as the law allows), those teachers were 50 percent more likely to transfer schools and 66 percent more likely to leave the system than teachers who were awarded tenure. These findings showcase that just the act of delaying the tenure decision can result in presumably weaker teachers self-selecting an option that may be better suited for them (and consequently their students).
New York is particularly interesting because districts in the state can keep delaying their tenure decisions for as long as they like. Data below highlight what happened to the 1,369 teachers whose tenure was extended in the 2011-2012 school year (623 had at least one extension previously) in the following school year.
Questions remain about how multiple tenure extensions will affect the overall quality of the teacher pool. Do teachers who receive a second or a third extension leave at even greater rates than those here did after receiving a first? Are they continually being replaced by more effective teachers, as happened in this instance? While a seemingly never-ending extension policy is not a good idea (at some point you have to cut bait), if teachers choose to leave at greater rates every time they get another extension and are consistently replaced by more effective teachers, then the city's overall teacher quality should increase - unless a law of diminishing returns is at work.
With these questions in mind, initial data certainly suggests some real benefits for the quality of the teacher workforce.
However, an earlier policy change complicates this picture, perhaps amplifying the positive outcomes that may be tempting to attribute only to the change in the tenure policy and Klein's implementation. At the same time, New York City also stopped the practice of force placing teachers who had been "excessed," allowing principals the right to refuse to take in a displaced teacher. Since the excess pool is (by reputation, at least) a dumping ground for low-performing teachers, their absence from the teaching pool may also contribute to the finding that new teachers are more effective than those they replace. But given other factors at play (including a hiring freeze that took effect the same year as the new tenure policy, in which Chancellor Klein required principals to hire teachers from the Absent Teacher Reserve Pool), it seems fair to say that this policy does not wholly explain the positive change in the applicant pool.
Timeline of major teacher quality policies in New York City, 2005-2006 to 2014-2015
It's unlikely that the new union-friendly NYC schools administration will continue Klein's tenure and excess policies, as neither was something the union favored. In any case, this study is especially timely as two lawsuits (modeled after the famous Vergara v. California case) that attack teacher policies such as tenure and last in, first out layoffs, have been filed in New York. One side or the other is bound to bring up this research-- but oddly enough, it's not clear which side it helps.