I don't think it is so easily understood to pre-meds. The salary difference to do a significant amount of research within academics is 2 to 3
fold less than your private practice options in many specialties. The salary within research often 2 fold less or more than your more clinical academic options. When I tell medical students about these salary differences the answer I frequently receive is the equivalent of "nuh-uh". It's unbelievably different, and with research funding as poor as it is, things do not seem like they are going to change any time soon.
Further, the job security within these research positions is directly tied to your ability to publish and get grants. Thus, you have a significant risk of failure compared to a mostly clinical environment where all you need to do is take care of patients to do just fine. Even further, you're often looking at extended fellowship/post-doc at $60k/year for another year or two before you can even start looking for research based positions when you can go out into private practice and start making $250k or more.
The frustration component in all this when you are 35 years old is palpable. One wants a decent quality of living. Especially if you have a family in a high cost of living area, you may not even be able to live on the poor salary they are paying fellows or "instructors" (poorly paid limbo land until you can get a tenure track position). Further, many want to be "the boss" as opposed to having grants and protocols rejected and having some review committee (internal AND external to the institution) give you crap about everything you propose. This as opposed to private practice or most of clinical practice where you almost never get questioned. You'd think this was a very ego-centric thing to say, but when you're working 60 - 80 hours a week juggling many different things, and people come after you because you forgot to put one word on a form so your protocol is being rejected or delayed for several weeks... This stuff happens virtually every day and it begins to make you very frustrated.
I think todds is making some excellent points. We had a long discussion recently on this topic at
http://forums.studentdoctor.net/showthread.php?t=900721 (I'm at post #36)