I think with the parliamentary model, it’s probably best to assume away as many of the problems with group rationality as you can.
A big source of problems in group rationality is asymmetric information, and for the parliamentary model we can just assume that all the delegates can costlessly learn everything about all the other delegates, or equivalently that they differ only in their morality and not in their information set.
Another big source of problems is that coalitional behavior can lead to arbitrary and unfair outcomes: for example if you start out with three equal individuals, and any two of them can ally with each other and beat up the third person and take their stuff, you’re going to end up with an arbitrary and unfair situation. For this perhaps we can assume that the delegates just don’t engage in alliance building and always vote according to their own morality without regard to strategic coalitional considerations. (Actually I’m not sure this paragraph makes sense but I’ve run out of time to think about it.)
I’m probably missing other important group rationality problems, but hopefully this gives you the general idea.
I think with the parliamentary model, it’s probably best to assume away as many of the problems with group rationality as you can.
A big source of problems in group rationality is asymmetric information, and for the parliamentary model we can just assume that all the delegates can costlessly learn everything about all the other delegates, or equivalently that they differ only in their morality and not in their information set.
Another big source of problems is that coalitional behavior can lead to arbitrary and unfair outcomes: for example if you start out with three equal individuals, and any two of them can ally with each other and beat up the third person and take their stuff, you’re going to end up with an arbitrary and unfair situation. For this perhaps we can assume that the delegates just don’t engage in alliance building and always vote according to their own morality without regard to strategic coalitional considerations. (Actually I’m not sure this paragraph makes sense but I’ve run out of time to think about it.)
I’m probably missing other important group rationality problems, but hopefully this gives you the general idea.