[EM] sortition/random legislature Was: Re: language/framing quibble

Tue Sep 16 09:49:24 PDT 2008

```Raph Frank wrote:
> On Sun, Sep 14, 2008 at 8:56 AM, Kristofer Munsterhjelm
>> A random assembly also resists the attack where one corrupts
>> candidates, simply because it's not clear who the candidates are
>> going to be.
>
> There is also the effect that a person who wants to be a candidate
> may need support to have any chance at all.

What do you mean?

>> I don't know if randomness, or more generally, a weak
>> voter-representative link is required for this resistance. It might
>> be, for a single given representative, but a method where voters
>> elect groups and some subset of each group is taken could also be
>> resistant to this, if it's not obvious beforehand which subset is
>> taken.
>
> Interesting.
>
> You could have a system with PR-STV where half of the elected
> candidates are excluded from consideration and then the election is
> held a second time.

One way of doing this would be to take a leaf from genetic algorithms.
Using either roulette selection or tournament selection, pick until you
have the council size.

Here's an example for roulette selection. The strategy would need a
method that returns an aggregate scored (rated) ballot, where that
aggregate is a proportional completion. Six candidates, three to be elected:

Score   Name    Cumulative score
0.9474: A       0.9474
0.6680: B       1.6154
0.3046: C       1.9200
0.2980: D       2.2180
0.1502: E       2.3682
0.0015: F       2.3697

We pick a random number on [0, 2.3697). We get 1.85603, so the first
with cumulative score greater than 1.85603 is elected. That's C. Next,
the random number is 2.04665. D is elected. Next, 0.738655. A is elected.

So A, C, and D are elected. The candidates with greater electoral
support have greater chance of being chosen, but for any candidate,
there's still a nonzero probability that some other will be selected
By running the scores through a function, one could make the method
regard the electoral results more (by amplifying the gaps in scores) or
less (by evening them out).

However, in general, there's a problem with such hybrids. The problem is
that, for elections to work, the people must know the candidates to at
least some extent. Because of this, candidates are going to have a
history - they will be persistent, and some candidates will run multiple
times. But this means that they can be corrupted, since the hypothetical
conspiracy know who to target. If you elect groups instead (or parties),
the conspiracy or lobbyists are going to target those who decide the
group composition - the party management in the case of parties. The
effect will lessen if there are many groups, or the method supports
independents, but it won't disappear.

There seems to be an inescapable tradeoff here, at least unless one
"thinks outside the box", like with delegable proxy.

```