Many school districts allow employees to accrue unused sick days without limit and cash them out upon retirement. In the Detroit district, for example, such a policy cost the district $12.5 million in unused sick leave in 2010-11. It’s a major problem, but too many school districts are only taking baby steps to correct it. In the small Holton, Michigan district, support personnel earn one sick day for each month worked. They’ve been allowed to accrue unused sick days without limit and cash them out upon retirement, or take extended leaves for any reason. But now school officials are patting...