Phased retirement policies are more or less attractive financially and more or less accommodating of individual differences. They are also implemented in varying ways, variations that especially affect departments and academic programs.

In the late 1980s and early 1990s, the graying of America's college and university faculty coincided with new federal regulations that prohibited mandatory retirement. So in order to both encourage faculty retirements and assume better control of when positions would be vacated about half of all U.S. colleges and universities adopted various…