[EM] Hare and Droop, d'Hondt and Sainte-Lague

[Adam Tarr]

I not sure the parallel between Hare and Sainte-Lague, and d'Hondt and 
Droop, applies more generally than the two-seat, two-parts case.  But anyway,

Kevin Venzke wrote:

>Let's say we're in Chile, so this is a two-member district:
>Party A: 21,000 votes, 67.74%
>Party B: 10,000 votes, 32.26%
>total: 31,000
>
>My thought: Although it would be nice to give a seat to a party that got 
>nearly a
>third of the vote,

It would be; this minimizes the error from proportionality in the final 
result.  In the example above:

The ideal proportionality would be party A getting 1.35 seats and party B 
getting .65 seats.

If you give party A 2 seats, 21,000 voters were over-represented by .65 and 
10,000 voters were under-represented by .65.

If you give each party 1 seat, 21,000 voters were under-represented by .35 
and 10,000 voters were over-represented by .35.  Obviously, the error is 
nearly half as small.

>  wouldn't it be unfair to penalize party A for not splitting into
>two equal fragments?

That's exactly the argument I used for employing d'Hondt in proportional 
approval voting (PAV).  Webster/Sainte-Lague is closer to perfectly 
proportional in the ideal, but it creates vote-splitting incentives that 
Jefferson/d'Hondt does not.

-Adam