Principals Focus on Retaining Highly Effective Teachers

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When current U.S. education secretary, Arne Duncan, headed the Chicago Public Schools in 2004-05, the city implemented a new collective bargaining agreement that covered teacher dismissal policy: principals were given more flexibility to dismiss non-tenured teachers. Now a new study by University of Michigan economist Brian Jacob finds that when given the authority, principals make dismissal decisions that put a premium on teacher effectiveness and student achievement.

Jacob found that principals are more likely to dismiss teachers who received poor evaluations in prior years; who are frequently absent; and at the elementary level, who had demonstrated less effectiveness in raising student achievement in prior years than their peers who were not dismissed.

Comparing the characteristics of dismissed versus non-dismissed untenured teachers within the same school and year, Jacob was able to determine how much weight principals place on a variety of teacher characteristics. Teachers who were given a rating of “satisfactory” in the prior academic year were 22.1 percentage points more likely to be dismissed than teachers in the same school who were given the highest rating, “superior.” Teachers rated “excellent” were 4.3 percentage points more likely to be dismissed than those rated “superior.”

Teachers who were absent 11 to 20 times between September and March of the current school year were 11.3 percentage points more likely to be dismissed than their colleagues who were never absent, and teachers absent 6 to 10 days were 3.5 percentage points more likely to be dismissed.

Among elementary school teachers for whom direct measures of effectiveness in raising student achievement were available, less effective teachers were also more likely to be dismissed. Specifically, teachers who were one standard deviation less effective (equivalent to the difference between a teacher at the 35th percentile and an average teacher) were associated with a 7.1 percentage point increase in the probability of dismissal.

Jacob examined dismissal among non-tenured teachers in the school years 2004-05, 2005-06, and 2006-07. His sample of schools consists of 16,246 elementary school teachers and 7,764 high school teachers working in 588 schools. He investigated the relationship between teacher value-added data and dismissal in a subsample of 803 elementary school teachers and 1,134 high school teachers for which value-added measures are available.

Comparing the year immediately prior to establishment of the new policy with the first two years of the policy’s implementation (2005 and 2006), Jacob finds that the total separation rate of non-tenured teachers increased by roughly 9 percentage points. Among other findings are that dismissed teachers who were subsequently rehired by a different school are more likely to be dismissed again than other non-tenured teachers in their new school. Jacob infers from these results that “many of the initial nonrenewal decisions were not idiosyncratic, stemming from a particularly bad match…but reflected a concern with the teacher’s general productivity.”