In “Teacher Layoffs, Teacher Quality, and Student Achievement: Evidence from a Discretionary Layoff Policy,” Brown University’s Matthew Kraft examined the effects of discretionary teacher layoffs by the Charlotte Mecklenburg Schools (CMS) in 2009 and 2010.  What makes this unique is that school administrators, rather than central office staff, used performance-based criteria to decided who would be laid off.

Kraft notes that CMS “eliminated almost 2,000 employees, including over 1,000 teaching positions in the two years following the onset of the Great Recession.”  (It is ridiculous to have to say this, but someone, somewhere will be tempted to blame Republicans for these layoffs.  The Democrats controlled state government during the 2009 and 2010 school years.)

So, what happened?  Kraft concludes,

I find evidence that laying off a more effective teacher, as measured by either subjective or objective performance metrics, decreased mathematics achievement in the following year compared to laying off an ineffective teacher. In contrast, laying off a more senior teacher had no effect on achievement compared to laying off an early-career teacher. When compared simultaneously, measures of teacher effectiveness strictly dominate seniority as predictors of the effect of teacher layoffs on future achievement. Estimates across models even suggest that laying off an ineffective teacher in CMS raised grade-specific student achievement in the following year although these estimates do not capture any potential negative school-wide effects of layoffs.

Got that?  When school administrators laid off low-performing teachers (as measured by valued-added scores), student achievement improved.  Achievement dropped when better teachers were let go. No surprise there.

In addition, seniority had no effect on student performance.  This confirms that personnel decisions based on experience levels, such as “first in, first out” policies, are silly.

The study will be published in the fall issue of Education Finance and Policy.