I personally would much rather a random Joe over a nuclear engineer when deciding these things. An average joe is coming at it tabula rasa or as close to that as you can expect. A nuclear engineer is someone who is very much inclined towards nuclear energy. It's the same reason that we don't compose juries of cops.
I can see the merits of soritition. But the main appeal is that it's directly without filtering. It's the only system that gives a millionaire and a hobo equal voice. If you start biasing the system in favor of people who are members in good standing of elite fields you are merely replacing one oligarchy with another. Much better to just go with proportional representation where there is at least an incentive to represent any view that isn't being represented.
Well, first of all to the it will just be an entire body concerned with only it's self interest, that is why I would want activists on such a board. So there is somewone, who maybe not knowledgeable, is virulently contesting the self interest of the Nuclear engineers. They are just more radical versions of average joes. An average joe also doesn't have the ability to become sufficently educated in a subject such as nuclear energy in a given amount of time to make a good decision. Proportional represntation would still allow people with no knowledge about nuclear energy to vote for politicians with explicit regulatory policies concerning nuclear energy, and thereby create a regulatory body that is ethier lacking in knowledge or is hampered by ideology.
Lemme point out that "What should be done" decisions don't generally require any sort of expert opinion, except when explicitly dealing with a highly technical topic. So for what I'm saying, you don't (for instance) need a bunch of generals deciding whether you go to war over some international incident, but you would want them for figuring out how you do it and what's a feasible option or acceptable cost. This is already what is done, by my understanding of the military, you basically just extend this principle to information technology, education, environmental regulation, etc. (EDIT: If it worked the way I'd like it to, which it doesn't since the "This is done in some areas already" part of my last sentence doesn't apply to the rest of this post) The non-experts contribution goes as far as, "Yeah, we think there needs to be less smog," and mutual veto power (the non-experts for impractical costs, the experts for impractical goals, though that's an extension of existing principle).
Also, everybody would get a pony because it is equally plausible and will probably work out about as well.
Yeah all regulatory bodies are already unelected, the commision via soritition would just remove any electoral check on the regulatory bodies. I would also argue that the equivlent of the congress (I.E. the committie made up of just average people) should only be allowed input into the budget process in terms of having to vote for any increase in marginal tax rates propesed by the budgetary committe (Which I think should be mostly economists with a minority of average joes, so the economists can eliminate any thing that is just purely distorting without any substantial benefit, like a subsidy for sugar beets. And the joes are just there...to... well I don't llnow give the people some sort of input?).
See I have faith that if we had a government composed of people with multiple conflicting interests, even if they aren't average joes, they would come to an solution aggreable to the people.