A new study examining teacher absentee rates in North Carolina has turned up some surprising results. Yes, teachers take off significantly more days than people do in other professions--but not all that much considering the performance demands of teaching and the predominance of young women in the profession. Yes, teachers working in schools serving poor children are more likely to be absent--but the variance is not shocking, with an average of one more missed day in a school year (nine versus eight). However, if a child is poor, the odds are much greater that s/he will be assigned to a school with a history of high absenteeism among teachers. In other words, there are many more schools serving poor children with above average absentee rates than there are schools serving children who are not poor.

Duke researchers Charles Clotfelter, Helen Ladd and Jacob Vigdor continue their lucrative mining of North Carolina school data, giving us not only a more accurate picture of absenteeism, but its impact on student learning in classrooms. They calculate that a substitute in the classroom for ten days has about 20 percent of the deleterious impact on student learning that first-year teachers generally have. Given that just about the worst thing you can do to students (educationally speaking) is assigning them a first year teacher, missed days quickly add up to having serious consequences, especially when the effects accumulate year after year.

One of the most interesting discussions in the paper is that the state and district rules that govern how absences should be handled have an observable impact on absentee rates. When teachers in North Carolina finish taking the ten "penalty-free" days that they are permitted, they must then pay $50 towards a substitute for each additional day that they miss. Not coincidentally, most teachers miss no more than ten days.

Given the high cost (financial and social) of missed days, Clotfelter et al suggest that states and districts consider a much earlier penalty for missed days, which could be compensated by a higher salary. It's clearly an economist's solution, failing to factor in the psychological impact of having to pay for being sick, no matter what your salary is. A more workable policy solution might be to give principals direct control over a distinct pot of money--out of which they would pay their substitute teachers and also award teachers with high attendance at the end of the school year. Such a fund would serve the useful purpose of alerting districts to principals who tolerate frequent and excessive absenteeism among their staffs.