Re: [EM] [ESF #420] Points, regions and contiguity
Cross posting this. Also, I think I have figured out the full set of rules, at least for a convex shape. On Sat, Nov 28, 2009 at 5:11 PM, Raph Frank raph...@gmail.com wrote: When trying to create districts out of blocks, ensuring contiguity adds an additional layer of complexity. The ideal situation would be if the blocks could be treated like points and a single line used to divide the blocks into 2 groups. There might be rules for other simple curves like arcs and parabolas, but no point in complicating things. Each block counts as a vertex and it is connected by an edge to all vertexes with which it has a boundary. The rules are - each vertex must A) be within the convex hull of the vertexes that it is connected to or B) be on the convex hull of the entire shape, and be connected to the previous and next vertexes on the boundary Notes: If a vertex is within the convex hull of its neighbours, then no 1 line can cut the connections to all of its neighbours. If the vertex is on the convex hull and is connected to the next and previous vertex, then no 1 line can cut connections to both of those vertexes, unless the line separates the vertex from all the other vertexes (so still technically produces 2 contiguous regions). A vertex that breaks the above rules could be fixed, by combining it with a neighbour. For example, on: www.electionsciencefoundation.com/temp_images/convex_vertex.png The red vertexes break the rules. Each one is removed and the red lines indicate the new boundary. The effect is to make the concave part of the boundary strictly concave. Also, unless the line cuts the actual boundary, it cannot cut the vertex based boundary. Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Block group map of Texas
http://bolson.org/dist/TX/txmask.png http://bolson.org/dist/ME/memask.png (All of the states should be available by similar URLs by state postal code. Note the odd XX/xx capitalization.) On Nov 28, 2009, at 6:57 PM, Raph Frank wrote: I generated some pdf maps of Texas. They are pretty big as they include all the lines that are included in the census data. They would stress even the best of computers. However, it shows the kind of shapes that are included in the census system. County - 1MB (7MB expanded) http://www.electionsciencefoundation.org/temp_images/county.zip Tract - 4MB (32MB expanded) http://www.electionsciencefoundation.org/temp_images/tract.zip Block Groups - 7MB (60MB expanded) http://www.electionsciencefoundation.org/temp_images/tract.zip I also did a block one, but it comes to 420MB. Election-Methods mailing list - see http://electorama.com/em for list info Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Anyone got a good analysis on limitations of approval andrange voting?
Robert Bristow-Johnson wrote (9 Nov 2009): Of course IRV, Condorcet, and Borda use different methods to tabulate the votes and select the winner and my opinion is that IRV (asset voting, I might call it commodity voting: your vote is a commodity that you transfer according to your preferences) is a kabuki dance of transferred votes. and there is an *arbitrary* evaluation in the elimination of candidates in the IRV rounds: 2nd- choice votes don't count for shit in deciding who to eliminate (who decided that? 2nd-choice votes are as good as last-choice? under what meaningful and consistent philosophy was that decided?), then when your candidate is eliminated your 2nd-choice vote counts as much as your 1st-choice. These statements suggest a misunderstanding of how STV voting works and what preferences (US rankings) mean in the STV voting system. In all STV elections, the preferences are contingency choices. Your vote is transferred to your second choice only in the event that your first choice cannot secure election or does not need you support to secure election. This is most easily seen in single-winner STV elections (US = IRV), where the sequence of rounds is exactly analogous to the sequence of rounds in an exhaustive ballot (eliminating one candidate at a time in successive ballots). The only difference is that in an STV (IRV) election you don't know what all the other voters did in Round 1 when you come to give your second choice. So the preferences (= contingency choices) marked on an STV ballot are quite different from the preferences marked on, for example, a Borda ballot where some attempt will be made to use all of the information simultaneously. The same applies to STV multi-winner elections (STV-PR), though the connection is not so obvious in versions of STV that use fractional transfer values to remove the otherwise unavoidable element of chance. However, the contingency choice nature of the STV-PR preferences is obvious in those versions of STV-PR that use whole vote transfers, e.g. Cambridge MA and the Dáil Éireann. It is even more obvious in Thomas Hill's original application of STV-PR when the boys formed lines in the schoolyard to show their support for the various candidates. These STV preferences are all quite clearly contingency choices and they should not be interpreted in any other way. James Gilmour No virus found in this outgoing message. Checked by AVG - www.avg.com Version: 9.0.698 / Virus Database: 270.14.86/2533 - Release Date: 11/28/09 19:34:00 Election-Methods mailing list - see http://electorama.com/em for list info
Re: [EM] Anyone got a good analysis on limitations of approval and range voting?
On Nov 29, 2009, at 6:37 PM, James Gilmour wrote: Robert Bristow-Johnson wrote (9 Nov 2009): Of course IRV, Condorcet, and Borda use different methods to tabulate the votes and select the winner and my opinion is that IRV (asset voting, I might call it commodity voting: your vote is a commodity that you transfer according to your preferences) is a kabuki dance of transferred votes. and there is an *arbitrary* evaluation in the elimination of candidates in the IRV rounds: 2nd- choice votes don't count for shit in deciding who to eliminate (who decided that? 2nd-choice votes are as good as last-choice? under what meaningful and consistent philosophy was that decided?), then when your candidate is eliminated your 2nd-choice vote counts as much as your 1st-choice. These statements suggest a misunderstanding of how STV voting works and what preferences (US rankings) mean in the STV voting system. i know earlier someone (it might've been James, i dunno) wrote that STV (i think that's what it's called in Australia) is called IRV in the US. i dunno to what extent that is true, but assuming it is, i understand exactly how IRV works as used by a few municipalities in the US, specifically what was used in Burlington VT which i think is identical to how it is in Cambridge MA, SF CA, someplace in NC, and Mpls/StP MN. to how the method works in Australia, i do not know first hand. also, i case you're interested, i voted for IRV for Burlington in 2005 (it has been used in two elections since), and in the referendum it faces this coming spring, i'll likely vote against recalling (abolishing in favor of the FPTP/delayed_runoff we had before) IRV. the issue to me is that the single-transferrable vote (as done in our domestic IRV) is the wrong algorithm to tabulate the votes in a multi- candidate election where no candidate gets a majority of 1st-pick votes. In all STV elections, the preferences are contingency choices. that is true. i fully support a contingency choice is multi-party/ multi-candidate elections. Your vote is transferred to your second choice only in the event that your first choice cannot secure election or does not need you support to secure election. that is *one* way to use the information of the contingency choices. if you are working out a complex problem with multiple directions of interest (which an election with more than 2 sincere candidates would be), you don't necessarily quantify votes as a commodity with some fixed value, and then, as i still point out, transfer these commodities around according to a candidate viability metric that arbitrarily says that 2nd-choice is no better than the last choice. you still haven't demonstrated why this contingent-choice information is the logical way to resolve a bunch of different competing contingency interests. we know how, if there were only two candidates, to decide between the two (assuming they don't tie). we know how to vote in that case (our sincere vote is the same as our tactical vote, easy), plurality = majority. assuming no funny business, no one can dispute the popular legitimacy of the winner. what we don't want to happen (assuming we want honest and democratic elections where tactical voting is not likely to work) is resolve an election differently between any two candidates differently than we would if those two were among a larger group of candidates. we don't want to have to think how we would vote differently in the two cases. if there is a Condorcet winner, and you are not that person, that Condorcet winner beat you, as far as the electorate is concerned. if it was just the two of you, he beats you. if it was you two along with N-2 other candidates, he still beats you (as well as beating everyone else). This is most easily seen in single-winner STV elections (US = IRV), where the sequence of rounds is exactly analogous to the sequence of rounds in an exhaustive ballot (eliminating one candidate at a time in successive ballots). please don't patronize me. there is nothing you're saying here that i don't know. it is in how IRV does that that is the problem. it doesn't accomplish the very goals we had when we adopted IRV (not rewarding tactical voting thus eliminating the need to consider tactical voting so we can vote the way we want to and not worry about contributing to defeating our own political interest - voter regret). The only difference is that in an STV (IRV) election you don't know what all the other voters did in Round 1 when you come to give your second choice. you mean you don't have transparency on how the rounds were performed or is it that your STV is a delayed runoff where you come in later? because i can't see the difference. in the IRV i am familiar with, you order your candidates before knowing how any round turns out. no one is returning to any polls.
