Retired CEOs can be enlightening interviewees because they are able to talk more freely about business life.

In the Netherlands, Peter Elverding gave an interesting review after leaving the company as head of the second largest chemical company DSM.

He regretted the appearance of activist shareholders calling on corporations to sell off their divisions or even to split them up completely.

If they published their attack, so Elverding, the share price would rise, by a factor of 10 percent.

But then the management can only lose: Either it bows to the pressure - or it sticks to its strategy, but then the course slips again, to the displeasure of investors.

At least with a view to the last point, the oil company Shell finds consolation.

Shell is now being publicly requested to split up by hedge fund manager Daniel Loeb, who has already pressed DSM.

But the share price fell on Thursday, impacted by poor business results.

Apart from that, however, Loeb's move increases the enormous pressure that Shell is already under in view of its carbon footprint.

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