They do not introduce controls from tax returns to see whether the explanatory power of teacher value - added for later earnings, college attendance, and other factors, falls. (educationnext.org)
Compared with the elementary schools in his sample, the variance in teacher value - added is lower in middle schools and random error is higher. (carnegieknowledgenetwork.org)
And, these results were robust to a variety of different ways of measuring teacher value added. (educationnext.org)