20% unemployment is going to make things very miserable for the other 80%. The people with decent EM gigs (Boomers, well-paid academics, etc.) will be protecting their turf like no one's business.
As someone once told me, EM is broad but not deep. By itself, this sets it up as a ripe specialty for PA/NP creep because their training and knowledge is not deep.
Given how most ED's function today, I have strong doubts that an MD is necessarily required over a midlevel to do some of the work. Mid-levels are perfectly capable of seeing and discharging the primary care, malingering, and other drug/meal/shelter-seeking patients. So at some hospitals, a significant percentage of the patient volume can be adequately serviced by a midlevel. By itself, this alone has bad consequences for the EM job market.
ED is triaging, stabilizing, and ruling in/out. A big turn off for me with EM is that nearly everything has been algorithmized. You really can't convince me that a smart mid-level won't be able to memorize and apply the algorithms, or that experience is not a better substitute than the exams/didactics/readings that we get engorged on during medical school. Just like you can't convince me that I didn't just waste four years of medical school to try to develop a sophisticated clinical impression, only to now chuck it out and apply mindless algorithms. For chrissakes, there are even pre-set algorithms for the initial differential diagnosis. While the "clinical impression" can help and aid any situation, it has been thoroughly devalued and replaced with algorithms in modern medicine and especially in the ED. The extent to which midlevels can triage, stabilize, rule in/out will further dent the EM job market, and algorithmizing and standardizing everything certainly helps them in this regard.
Finally, anything really serious can be consulted to the service that will admit the patient. Not only does this limit the ability of the EM physician to gain an advantage over a mid-level, this provides serious risk mitigation for the hospital administrator. If the mid-level is clueless, he or she can always consult Medicine or whomever. Or order a bunch of needless tests.
Feel free to rebut.