On-call scheduling has not been well received. It is a new trend in reducing personal costs. But, it causes workers substantial stress, since they do not know until a few hours before or the night before whether they will be working. This late notice makes arranging child care virtually impossible. Attorneys general from eight states and the District of Columbia are investigating the practice. So far, they have simply sent letters seeking payroll records and policies. But, those letters prompted some large companies to drop the practice. See ABA Bar Journal report.
I would expect on-call scheduling would have greater impact on female workers, since they are more often the workers arranging child care. So, this sort of practice would impose a greater burden on women. The practice would then constitute disparate impact on female workers. I could also see how such scheduling could also aversely impact workers with disabilities. This sort of business practice may cost an employer much more over the long-term than it saves near term.