Workplace abuse leads to decreased productivity, lower morale, increased absenteeism, and turnover (the bad kind — not the kind that results from not needing roles anymore). Imagine burning a big old pile of money. That's the equivalent of keeping an abuser on staff. Let's look at some of the hidden and not-so-hidden costs of keeping an abuser on staff:

Turnover. Examples: announcing the job opening, recruiting fees, interviewing time, and training time.
Lost opportunity. Examples: losing clients and the revenue associated with them and losing potential accounts from the work of competent employees.
Absenteeism. Cost: paid time off (sick leave and vacation)
Presenteeism (being at work but disengaged while there). Cost: lost productivity from that employee and any employee disengagement rubs off on. 
Legal defense. Regardless of there not being laws with teeth on the books protecting targets from workplace abuse, targets can still sue. And...

In a 2001 study, Researcher Judith Richman linked workplace harassment to drinking behaviors. In a multi-wave panel study at an urban university, targets who had more than two years of bullying had a stronger connection to drinking problems.

“These drinking behaviors reflect an attempt by targets to deal with the psychological stress,” say Loraleigh Keashly and Joel H. Neuman in their Employee Rights and Employee Policy Journal article. “Should such drinking continue, job performance and productivity is likely to suffer. For example, some research suggests that sixty billion dollars is lost in annual productivity as a result of alcohol abuse.”

The link isn’t shocking. What’s shocking is the failure of management to address root cause: workplace bullying. It’s far easier to blame a target for a drinking problem than a higher level employee for causing the unnecessary stress in the first place. That negligence to address the...