A Look at LIFO’s Impact on Student Achievement using Real World Data
Tough economic times are leading to teacher layoffs in many school districts, which is putting existing layoff policies in the spotlight. In the overwhelming majority of school districts, “last in, first out” (LIFO) provisions of collective bargaining agreements make seniority the main factor in determining which teachers are let go.
A new study by Dan Goldhaber and Roddy Theobald from the University of Washington looks at the characteristics of teachers who were targeted for layoffs in Washington state, and at the impact of LIFO provisions on student achievement. The study, “Managing the Teacher Workforce: The consequences of ‘last in, first out’ personnel policies,” will appear in the Fall 2011 issue of Education Next and is now available online.
Goldhaber and Theobald analyze data on 1,717 Washington teachers who were sent layoff notices in 2009 and 2010 to see which teacher and school characteristics influenced the likelihood of a teacher receiving a layoff notice. The authors write that “our findings largely comport with what one would expect given seniority provisions in collective bargaining agreements.”
The authors next look at what would happen if the existing seniority-driven system of layoffs were replaced by an effectiveness-based layoff policy, in which teachers are ranked according to their value-added scores and districts lay off their least effective teachers . Here are their findings:
The overlap between the subgroup of teachers who received a layoff notice and the subgroup of teachers who received one in our simulation is relatively small—only 23 teachers (or 16 percent of the teachers for whom we could estimate value-added who received a layoff notice). Moreover, because the teachers who received layoff notices in our simulation were more senior (and had higher salaries) than the teachers who actually received layoff notices, the simulation results in far fewer layoffs. We calculate that districts would only have to lay off 132 teachers under an effectiveness-based system in order to achieve the same budgetary savings they would achieve with 145 layoff notices under today’s seniority-driven system, a difference of about 10 percent.
As expected, there are large differences in classroom effectiveness between teachers who actually received layoff notices and those who would have received them in our effectiveness-based simulation. The two groups differ by about 20 percent of a standard deviation in students’ math and reading achievement. The magnitude of the difference is striking, roughly equivalent to having a teacher who is at the 16th percentile of effectiveness rather than at the 50th percentile. This difference corresponds to roughly 2.5 to 3.5 months of student learning.
The complete study, “Managing the Teacher Workforce,” is available here.
A press release summarizing the study can be found here.