Should CEOs stay on the board after they step down?

Investors applauded when former DuPont CEO Ed Breen abruptly reclaimed the job on Tuesday, with former CEO Marc Doyle dismissed immediately. But in a sense, Breen wasn’t the former CEO at all. He had been CEO of DowDuPont before it was split into three companies, and when DuPont became independent last spring, Breen took the…