The failure of unweighted inclusive Gregory STV

The single transferable vote (STV) is a family of voting systems designed to achieve proportional representation. It is widely used in Australia in multi-winner elections, in both governments and private contexts.

Most STV systems in use in Australia fall into one of two categories: exclusive… »

A conceptual primer on the single transferable vote – 6: Meek method

In part 5, we presented the weighted inclusive Gregory method. In that part and all previous parts, during the distribution of preferences we have ‘skipped over’ any candidates who have already been elected, as we said that to give extra votes to any of… »

A conceptual primer on the single transferable vote – 5: Weighted inclusive Gregory method

In part 4, we presented the Gregory method, which removes random effects from STV. In that part, we continued with a decision made in part 3 to restrict the ballot papers which can contribute to a surplus distribution, yielding the exclusive Gregory method.

To… »

A conceptual primer on the single transferable vote – 4: Exclusive Gregory method

In part 3, we discussed a refinement to random transfer STV, noting that even in refined form it is still subject to random effects. In this part, we introduce a method which eliminates randomness from STV completely.

For the sake of illustration, let's again… »

A conceptual primer on the single transferable vote – 2: Andrae's and Hare's methods

At the end of part 1, we provided an outline of STV:

a voting system which mimics the effect of repeated SNTV, where each voter has only 1 vote at a time, but where the voting system automatically redirects wasted votes from candidates elected