Hi William,
The answer is yes, at least according to the PMI Salary Survey and Report:
www.pmi.org/learning/careers/project-management-salary-survey
Personally, I have gained an enormous salary bump by having earned the PMP (and PgMP) Credentials:
Of course, this might vary and depend on specific circumstances.
But PMP gives you an advantage in the market; no one could deny that, I guess.
Not only in terms of salary, but for me, it opened many doors that would not have opened without PMP.
BR,
Markus
