Employee turnover requires that you recruit a new employee of similar qualification, skills and knowledge, if not better. Having lost valuable expertise, there is no assurance that you can find a suitable replacement. This is additional cost to your organization.
Absenteeism will cost your organization in terms of valuable work-hours lost and increased administrative overheads. There is also the numerous hours spent by management in resolving absenteeism problems among employees.
An employee who habitually absents himself or herself is within the category of difficult employees.