Joanne Jacobs covers a new study using North Carolina's extensive historical value-added student achievement data:

C. Kirabo Jackson and Elias Bruegmann analyzed 11 years of data on North Carolina schoolchildren for their study, which will be published in Applied Economics, a peer-reviewed journal.

Merit pay incentives should focus on rewarding school teams, not individuals, said Jackson, who teaches labor economics at Cornell.

 

EdWeek summarizes the crux of the findings:

...for the average educator teaching in a grade with three other teachers, replacing one peer with a more effective one has a spillover effect of .86 percent of a standard deviation on students’ test scores.                

For math, that equates to roughly one-tenth to one-fifth the size of the impact that is estimated to come from replacing the students’ own teacher with a better one, the paper says.

This is probably especially relevant to the Outcomes team, but it gives us some new value-added perspective in Measures as well. The full study is available here.