> SPI should adopt a system widely used elsewhere. > > STV is the only widely adopted proportional voting system suitable for > SPI (the others are supplementary/additional member systems, and party > list systems).
I agree that STV is a pretty reasonable system, in fact it is the best widely-deployed system appropriate for non-party-list proportional representation. However, living as I do in the Republic of Ireland, I have some personal experience with pathologies of STV which are addressed by RRV. The mathematical analyses of RRV have convinced me that RRV basically dominates STV, in that although RRV does have some pathologies (as it must, due to Arrow's Theorem etc) its pathologies are a strict subset of those of STV, and it cures the most egregious-in-practice pathologies of STV. Let me describe two STV pathologies that actually happened in the last couple years, and certainly raised my eyebrows. First, the result of an election can depend on the order of ballots. In one case, the order was scrambled during a recount, resulting in uncertainty about the correct result. Strategic re-ordering of ballots is an actual issue. The most common attempt to address this is an initial random shuffle, with the consequent order religiously preserved for purposes of replication. Second, there was a case where (to simplify) candidate X in a Dublin precinct sent around a circular asking their supporters to list X second on their ballots and Y first, where Y was a candidate with ostensibly no hope of winning. This was to serve to increase the power of these ballots. My native Irish friends found this a delightful tale, particularly with all the fascinating details filled in and appropriately embellished. Perhaps it is. But it didn't make me more of an STV fan. Cheers, --Barak. -- Barak A. Pearlmutter <[email protected]> http://barak.pearlmutter.net _______________________________________________ Spi-general mailing list [email protected] http://lists.spi-inc.org/listinfo/spi-general
