To the private sector, PhD is known as permanent head damage. If you don't have working experience, but have PhD. There isn't much an advantage at all. Either what you have research on is very niche or it is still commercial not viable. Many PhD, you will have 1 entreprenur. But that probability is still much worse off that other business lines.

In fact, what in real life. Those that works for a few years. And they got a managerial post, they will go for MBA. It is more of a networking through the course.

Put it in simple fact. You are the hiring VP. You are looking for senior managerial position. Do you think you get someone in just because of his education background. Or more on recommendation and creditations?

Not forgeting creditation is also due to recommendation and networking. Fact in real life, it is all about networking and also your talent also counts.

Certification is just a knock on the door for the 1st few years. After that, it doesn't really have a big impact.