[EM] Sortition and the Delegable Proxy system

Kristofer Munsterhjelm km_elmet at lavabit.com
Wed Jan 25 09:52:58 PST 2012

```On 01/24/2012 07:28 AM, Bryan Mills wrote:
> I've been looking at a voting system over the past week or so that I
> think is really interesting: a combination of the "delegable proxy"
> system with a sortition procedure to elect a standing legislature.
>
> My objective is to find a way to use conventional voting
> infrastructure to elect a proportional legislature of bounded size by
> strategy-free means.  I'm not yet 100% certain whether the system
> actually is strategy-free; I think it is but I haven't yet found a
> proof.  (It's non-deterministic, so I don't think it runs afoul of
> Arrow or Gibbard–Satterthwaite but proportionality is only
> probabilistic.)
>
> I can't imagine that I'm the first to examine this system, but I
> haven't found it in any of the voting literature I've read so far
> (most of Voting Matters and part of the Electowiki).  My own writeup
> can be found at
>
> Any direct insight or pointers to relevant documents would be appreciated.

I think it is strategy-proof, but I wonder if people would irrationally
reason something like this:

"My chance of winning is very low, so I shouldn't keep my hopes up.
Instead, I should delegate my vote so that I can feel I expressed myself
if [popular candidate] wins."

Now, that makes no sense, but if people were game-theoretically
rational, turnout would be very low (and it isn't). So I'm wondering if
the people would irrationally be more mass-like than you'd want of a
sortition-based system.

There might also be another problem: say that people delegate their
votes so that some famous candidates have a certain chance of winning,
but this chance isn't absolute. Then any of them could say "if I win,
that's great, I'll do what I want". In other words, the doubly random
nature of the process - first, where the candidates don't know who will
delegate to them, and second, where it's not certain they will win even
if lots of people delegate to them - could weaken the constituency
feedback, making the "famous" candidates more likely to do their own
thing than to take the voters' opinions into account.
Or, the public, knowing this, might delegate to people of which they
have a general good feeling, e.g. movie stars and the likes. They would
then reason something like "I know that whoever I delegate won't know I
helped him win. Thus I can't influence him, so who am I going to choose?
Well, I know of Harrison Ford (or whoever) and his political position is
somewhat close to me, so I'll pick him". Now, Ford's popularity as a
actor has, in itself, no bearing upon his political skills - he would
have a greater chance of winning for similar reasons to why, when asked
for a random number, people tend to pick odd numbers.

Let's try to formalize that a little. Ordinary sortition works by
picking a representative sample of the people. However, if the people
were unrepresentative in their delegation - preferring those who were,
for some reason or other, well known, then the sample picked by
delegated sortition would not be representative anymore. In ordinary
proxy democracy (liquid democracy, etc), on the other hand, giving your
vote to Ford is next to pointless - if lots of people do that, you have
no chance of pulling him in your direction, so you should vote for