I don't think anyone can really answer the "why" question the OP posted here, or whether on its face it's true.
Often people like to equate length of training with income and you cannot do that in medicine. Anesthesia residency is 4 years, Gen Surg is longer. Each have their fellowships. So the training is longer for a gen surgeon, on average. An interventional cardiologist needs PGY-7 (3+3+1) to get licensed, yet a Family Practitioner who is done in three years, working somewhere (very) rural, might make more than that cards guy who is in an academic center making 250K in a major city. Instead of his pp brethren making 800K putting in stents in Boca Raton.
So, training and length of training, just doesn't = $ in medicine. There are too many variables. Perhaps heart surgeons and brain surgeons are the exception in the surgery field.
Anesthesiologists jump into this mix here too. Some go into academia without fellowship and make their 275K, others get PEDS, or Pain and Hearts fellowships and step into private practice, in rural Virginia, and make 450K off the bat. It's really about how and where you choose to practice. Though, on its face, Gas is a higher paying specialty than many others.
I think Shemarty is right, I've spent months shadowing and observing anesthesia, 500 hours at least. It's fascinating if you have an interest in physiology, chemistry, etc. There will ALWAYS be the Surgeon v Anesthesia debate: who is more important, who is better compensated, who came first, who sits higher on the totem pole, can one exist without the other...bla bla. Anesthesia is a procedure laden profession that is well compensated. And, as you can see in the news recently, Michael Jackson, it's not just about infusing sedatives and saying nighty nighty and time to wake up. It's truly mind-blowing what these guys do. But take it with a grain of salt, I love everything about it.
We could probably set up every profession against another in medicine and ask these questions, why do radiologists make good money when pediatricians don't, typically. But these are things we are unlikely to change, however, valid questions in and of themselves.
D712