When a child misses a lot of school, he's also missing out on valuable classroom instruction time. In fact, students who miss excessive days of school tend to do worse on standardized tests than students who go to school most days of the year. More specifically, a 2010 study published in "School Psychology International" found that children between the ages of 7 and 11 who missed half a year of school lost the equivalent of 0.7 of a year's worth of reading test scores and the equivalent of a full year's worth of math test scores.
A student who misses many days of school must play catch up when he does attend his classes. The teacher, therefore, must take the time to remediate with the absent student. Doing so takes instructional time away from the other students, according to Linda L. Williams, author of an article published with the support of Valdosta State University. This can decrease the overall learning capabilities of the rest of the students because they're missing out on lessons that would have been taught if the teacher wasn't busy helping the chronically absent student catch up, Williams notes.
School systems rely on federal funding that's based on full-time student enrollment numbers for a given school year. When students are chronically absent, which is defined as missing 20 or more days per school year according to the "School Community Journal," schools don't get as much money as they would if all the students attended on a regular basis. For example, the Oakland Unified School District loses about $4 million per year due to absenteeism, according to Williams. Loss of revenue impacts all students because school districts may need to cut back on curriculum materials, books and adequate staff to make up for lost revenue.
Students who miss a lot of school are at an increased risk of dropping out of school all together, according to Williams. More than that, students who do drop out of school are at a higher risk for delinquency and criminal behavior. In fact, children are more likely to commit delinquent acts if they have irregular attendance habits, poor grades or if they've dropped out of school. Case in point: According to Williams, 82 percent of inmates in Georgia dropped out of high school.