In WPRI’s most recent education poll we asked Milwaukeeans which type of school they thought would be better at improving academic performance: a traditional school staffed by older teachers, or a an innovative school staffed with younger teachers.  48% of respondents picked the innovative school with younger teachers, 39% chose the traditional school staffed with older teacher.

The question got me thinking; what does existing data show about the relationship between age and academic performance in Milwaukee schools? To get at this question I combined information on the birth year of Milwaukee Public School (MPS) teachers from the Department of Public Instruction’s (DPI) all staff file with school level data from DPI’s accountability report cards.  Though the school-level report cards (for reasons I have pointed out in the past) are a far from perfect indicator of school success, it does allow me to test the relationship between the average age of teachers in a school and that school’s accountability score.

First, I checked to see if there was any significant difference in the average age of teachers in schools meeting and exceeding expectations, and, those in schools not meeting expectations under the new report card.  The average age of teachers in schools meeting and expectations was 45.4.  The average age of teachers in schools not meeting expectations?  45.1.  No big difference here.

I went through the same exercise using school student growth scores, which generally make up 25% of each school’s overall accountability scores.  The growth measure looks at changes in student performance over time, arguably making it a better indicator of how schools affect student achievement.  Here again, no big difference.  Teachers in low and high growth school are both about 45 years old.

However, when I run a regression analysis controlling for the effects of race, poverty, school size, and special needs status I find a statistically significant relationship between the average age of teachers at a school and a school’s overall accountability score.  The older the teachers, the higher the scores.  Specifically, for every 3.37 years older the average teacher in a school, the school’s overall accountability score goes up one point.

So what does this mean?  Older teachers are better than younger teachers in MPS?  Maybe. Maybe not.  It could be that higher performing schools attract teachers with seniority. It could be that teachers stay at higher performing schools longer than lower performing schools. Interestingly, when I run the same regression model using a school’s student growth score as the dependent variable I see no significant relationship.  So maybe teacher age has little to do with actually moving student scores over-time.

Whatever the reason for the relationship, it bears watching in Milwaukee as significant staff turnover (and loss of years of experience) occurs.  I’d also like to think this simple little analysis scratches the surface of the types of things an independent research entity with access to quality information on all schools in Milwaukee could do….if such an entity, and such a data system, existed.