Pros and cons of having your doctoral degree on our ID
I did add the degree to the passport, and I can tell you that so far it only had disadvantages (though no severe ones).


I added my master degree, and did not need a new passport since. So now that I have my PhD, its not even accurate anymore.
In China, authorities looked at my passport and me very sceptically, when I did not add my degree to the train ticket, and thus the name differed between passport and ticket. They did not understand my explanation, but let me pass on the train anyway ;)
Most time I book a flight ticket, I can only select Mr/Mrs as title. So I have to think everytime, whether I should add the degree in the name field. Usually I don't do it, hence again the ticket and the passport show different names. It caused a strange look in America, but no serious problems.
My new colleagues (in a foreighn country) looked at me like i was crazy, when they saw it.