What I suspected, and what you hint at, is that the insurance market isn't all that efficient in some areas. In some cases because there's limited information, in which case the only way to increase market efficiency is to do more research (which is so open ended it's impossible to know when you're doing "enough"), or to pad the results to account for errors. In other cases it's because there's been too much government interference, or the interference has had unintended side effects (I believe in market interference, I just believe it should almost always be to increase efficiency, where all to often our efforts are to subsidize a segment and that has too many follow-on consequences). Requiring insurance in specific areas might help this.