Olson, Linda S. Baltimore Education Research Consortium, July 2014. Absenteeism in the first month of school can predict poor attendance patterns throughout the year, providing an early warning sign for parents and educators to intervene and put students back on track, according to this brief which examines attendance in the Baltimore City Public Schools for pre-kindergarten through 12th grade students in September and throughout the rest of the 2012-13 school year. Olson found that: students who missed fewer than 2 days in September typically had good attendance rates for the entire year; half the students who missed 2-4 days in September went on to miss a month or more of school; and nearly 9 out of 10 students who missed more than 4 days in September were chronically absent that year.