Are there enough dermatologists?

A major topic of conversation is the numbers of dermatologists in the United States.

There are several arguments that there are simply not enough, including

1. Long wait times to see most dermatologists in urban areas.
2. Underserved rural areas across America.
3. Increasing reliance on 'physician extenders;' nurse practitioners and physicians assistants, to meet the need of patients in many practices.
4. Increasing prevalence of primary care physicians (or other specialties) acting as dermatologists.

1. Too few are being trained.
2. Too many are working part time, or quitting the profession entirely (for example, to raise children).
3. Too many are specializing (for example, in cosmetics) which limits the availability of general dermatology practitioners.