Comparing Teacher Turnover In Charter And Regular Public Schools

** Also posted here on “Valerie Strauss’ Answer Sheet” in the Washington Post

A couple of weeks ago, a new working paper on teacher turnover in Los Angeles got a lot of attention, and for good reason. Teacher turnover, which tends to be alarmingly high in lower-income schools and districts, has been identified as a major impediment to improvements in student achievement.

Unfortunately, some of the media coverage of this paper has tended to miss the mark. Mostly, we have seen horserace stories focusing on fact that many charter schools have very high teacher turnover rates, much higher than most regular public schools in LA. The problem is that, as a group, charter school teachers are significantly dissimilar to their public school peers. For instance, they tend to be younger and/or less experienced than public school teachers overall; and younger, less experienced teachers tend to exhibit higher levels of turnover across all types of schools. So, if there is more overall churn in charter schools, this may simply be a result of the demographics of the teaching force or other factors, rather than any direct effect of charter schools per se (e.g., more difficult working conditions).

But the important results in this paper aren’t about the amount of turnover in charters versus regular public schools, which can measured very easily, but rather the likelihood that similar teachers in these schools will exit.

In other words, are charter school teachers more likely to exit than regular public school teachers who have similar characteristics – experience, credentials, age, gender, etc – and work in similar schools (in terms of the percent of their students who get free/reduced-price lunch, racial composition, etc.)? It is only when you compare similar teachers in similar conditions between charters and regular public schools that you learn whether there are other factors at play – that is, aside from the measurable characteristics of teachers, students, and schools, could there be something about working for a typical LA charter school (such as long hours or problematic working conditions) that might lead to higher turnover rates?

In this regard, the findings for charter schools presented in this paper are somewhat striking (see other papers on this topic here, here and here; review of recruitment/retention literature generally here). Controlling for all other measurable factors in their model, the authors find that the odds of charter teachers exiting are still 33 percent higher than those of regular public school teachers. There is an even larger difference in secondary schools, where charter teachers are almost four times more likely to leave.

(Side note: This analysis does not distinguish between the different “types” of turnover, such as retirement, leaving for a different profession, or switching schools – the level and causes of the “charter effect” may differ by the type of turnover.)

These results suggest that the higher overall levels of teacher turnover in charter schools – which were the focus of most media attention accorded this study – might indeed be due to the conditions and/or practices in these schools, rather than the characteristics of their teachers or students.

It is, however, important to bear in mind that the results do not identify any actual, concrete reasons (e.g., work hours, difficulty in working in a start-up) why charter school turnover might be higher, only whether there is an association between working in a charter and the likelihood of attrition (relative to similar teachers in regular public schools). As is often the case with comparisons of charters and regular public schools in terms of achievement outcomes, the causal underpinnings remain elusive.

There was also another unfortunate aspect of the media’s coverage of this working paper: The tight focus on the charter school results seems to have precluded coverage of the numerous other findings reported in the paper, which were not related to charter schools. For instance, the study’s authors found that young non-white teachers were significantly more likely to exit than their white peers, and that the overall attrition dynamics differed rather sharply between elementary and secondary schools – e.g., the relationship between the odds of leaving and experience is stronger among elementary teachers, compared with those in secondary schools.

These and other reported findings are arguably more immediately relevant both for current policy and for future research than are the charter school differences, which are, as yet, difficult to explain and interpret, since the actual root causes (beyond working in a charter school, which is not very helpful) remain unclear. High turnover is an extremely important issue, and good studies that provide potentially-useful findings should not be killed in the charter crossfire.

- Matt Di Carlo