Research conducted by Donald Sull at the Massachusetts Institute of Technology and his co-authors found that predictable schedules had a marked effect on retention for blue-collar employees but did not affect white-collar ones.

麻省理工院的 Donald Sull 和他的合著者进行的究发现，可预测的时间表对蓝领员工的保有着影响，但对白领员工没有影响。