[EM] A simple Random Ballot proportional method

[Kristofer Munsterhjelm]

And here's a simple method I thought of for a multiwinner method. Would 
it be any good?

- Draw k assemblies using Random Ballot.
- Gather everybody who were selected in at least one of these draws, and 
set a deadline.
- If, after negotiations, at least 90% (or some high supermajority) of 
the gathered people agree on one of the k assemblies drawn, that outcome 
is chosen.
- Otherwise, if the deadline passes without agreement, draw another 
assembly using Random Ballot. That outcome is then chosen.

The idea is to exclude unlucky draws by using a negotiation phase. Yet 
there's little incentive to stall in the hope of getting a favorable 
outcome to oneself, because the post-deadline default isn't status quo 
but simply another random ballot council.

I suppose the main risk would that not enough people agree and then the 
final outcome turns out to be quite disproportional due to bad luck. The 
risk would be greater for smaller assemblies. Perhaps it could be 
lessened by running n different instances of the above in parallel, and 
as long as one of them decide upon an outcome, that outcome is picked. 
(If multiple do so, draw one at random.) But I'd have to consider it in 
greater detail to find out if that would be proportional.