Regular contributors to this blog never played truant from school. That is why they are leading happy and fulfilling lives as economists. Nonetheless significant numbers of schoolchildren do and, particularly if it has a negative effect on their educational attainment, we should be concerned about it.
The paper by Buscha & Conte examines this question using mixed effects estimators applied to data for Britain. And yes it does impact negatively on students' educational attainment though it is not a simple relationship.
An old working paper by me looks at some of the determinants of truancy applying simpler methods to PISA data for 6 countries