How do teachers respond to tenure?

I use the 2007 Schools and Staffing Survey to estimate the effect of tenure on K-12 teacher behavior. Estimates are obtained by exploiting the cross-state variation in the probationary period length of novice teachers. I find that in the year that teachers are evaluated for tenure, they spend significantly more of their own money on classroom materials. The teachers also participate more in school committees and extracurricular activities during the evaluation year. After increased activity during the tenure evaluation year, behavior appears to return to the baseline established prior to evaluation.