Is Teacher Attrition Actually Increasing?

Over the past few years, one can find a regular flow of writing attempting to explain the increase in teacher attrition. Usually, these explanations come in the form of advocacy – that is, people who don’t like a given policy or policies assert that they are the reasons for the rise in teachers leaving. Putting aside that these arguments are usually little more than speculation, as well as the fact that they often rely on highly limited approaches to measuring attrition (e.g., teacher experience distributions), there is a prior issue that must be addressed here: Is teacher attrition really increasing?

The short answer, at least at the national level and over the longer term, is yes, but, as usual, it’s more complicated than a simple yes/no answer.

Obviously, not all attrition is "bad," as it depends on who's leaving, but any attempt to examine levels of or trends in teacher attrition (leaving the profession) or mobility (switching schools) requires good data. When looking at individual districts, one often must rely on administrative datasets that make it very difficult to determine whether teachers left the profession entirely or simply moved to another district (though remember that whether teachers leave the profession or simply switch schools doesn’t really matter to individual schools, since they must replace the teachers regardless). In addition, the phenomenon of teachers leaving for a temporary period and then returning (e.g., after childbirth) is more common than many people realize.

Opportunity To Churn: Teacher Assignments Within New York City Schools

Virtually all discussions of teacher turnover focuses on teachers leaving schools and/or the profession. However, a recent working paper by Allison Atteberry, Susanna Loeb and James Wyckoff, which was presented at this month’s CALDER conference, reaches a very interesting conclusion using data from New York City: There is actually more movement within NYC schools than between them.*

Specifically, the authors show that, during the years for which they had data (1997-2002 and 2004-2010), over 50 percent of teachers in any given year exhibited some form of movement (including leaving the profession or switching schools), but two-thirds of these moves were within schools – i.e., teachers changing grades or subjects. Moreover, they find that these within-school moves, like those between-schools/professions, appear to have a negative impact on testing outcomes, one which is very modest but statistically discernible in both math and reading.

There are a couple of interesting points related to these main findings.