Tuesday, July 27, 2010

Minneapolis RCV Report: IRV Is No Magic Bullet

Dr. David Schultz (not be confused with Mark Schulze, of Schulze method fame) has posted his report for the Minneapolis Elections Department on the use of ranked choice voting [PDF] (more commonly known as instant runoff voting or IRV), as it was used in that city's recent elections. Schultz was (and apparently still is) a strong supporter of the use of IRV, having previously served as a board member for FairVote Minnesota, a fact he plainly states in his paper's Conflict of Interest heading. And this refreshing honesty continues throughout the document... which probably isn't good news for FairVote's or Dr. Schultz's objectives.

First on the chopping block is the claim that IRV increases turnout. Turnout for the 2009 IRV election was down 21% form the 2005 election. Now, there are many reasons for turnout to vary between elections--for instance, the report mentions that there weren't any particularly heated contests on the ballot--so this alone isn't certainly damning for IRV; but it surely doesn't help.

We also find that the well-advertised claim of decreased election costs turned out to not be true. We already knew this, based on a previous report, but it's worth reiterating: even when one-time costs, including voter-education costs, are ignored, the 2009 IRV election cost 20% more than the 2005 election. This is primarily a labor-cost issue, since Minneapolis was not able to find any voting machines capable of adjudicating an IRV election which meet the necessary security and accountability requirements set by law; so the vote had to be counted by hand. Schultz hopes that, perhaps, other towns in Minnesota will express interest in IRV, which will encourage the approval of the cost-saving IRV-capable voting machines. Considering the continuing problems of Diebold Premier Dominion Voting, I wouldn't hold my breath.

I do have one serious complaint about this report, and that's Schultz's claim that first past the post (FPTP, AKA plurality voting) is, like IRV, non-monotonic. This statement is unequivocally false, and the blatant attempt to whitewash this shortcoming of IRV stands out, painfully, against the otherwise honest assessments given throughout.

But my "favorite" part of the report is the section on Spoiled Ballots and Voter Error. Schultz begins by assuring us that "[T]he worst fears were not realized." By which he means IRV only quadrupled the ballot-spoilage rate, from 1.0% to 4.1%. It's true, previous IRV elections would suggest a six- or seven-fold increase in spoilage rates would be expected. Although it should be pointed out that, in addition to the 4.1% of ballots that had to be thrown out, an additional 6.4% had "errors" which the hand-counting procedure was able to "ascertain the intent of," for a total error rate of 10.5%. It's not clear how these ballots would have been handled by an automated system, had one been available.

Finally: how much of an impact did IRV have on the election? In all 20 single-winner contests, the candidate with the most initial 1st-place votes won the election. In 17 of these 20, the winner surpassed the 50% threshold immediately, and in the other 3 cases they did so after the first round of eliminations. But I don't want to hold this too strongly against IRV: as mentioned earlier, there weren't any hotly-contested races in this election. That usually means low-turnout and a lot of blow-out elections. Realistically, any electoral system would probably have come to the same conclusions in these races as IRV did. The true measure of an electoral system's quality is how well it can handle highly-contested and close-to-call elections. The predominant examples suggests that IRV would handle such elections poorly; but the Minneapolis data provides no real information for or against that proposition.

I hope that Dr. Schultz will carefully consider the empirical data that his report has highlighted, and that it will help to temper the misleading rhetoric that FairVote Minnesota has used, and which the national FairVote organization continues to use, to push for IRV's adoption around the country.


  1. Dale, thanks for this analysis. I wanted to make comment about the turnout in Minneapolis' first IRV election on Nov 3.

    Minneapolis had the lowest voter turnout since 1902, well over a hundred years.

    This was the lowest turnout since Mayor "Doc" Ames, also known as "The Godfather of Minneapolis left office while under investigation for corruption.

  2. Wow, I didn't know that.

    Perhaps I was too generous to Dr. Schultz.

  3. The mayoral race wasn't any where near competitive (the biggest predictor of voter turnout in Mpls elections) and there really were no races without incumbents and so IRV didn't really do much.

    I'd like to push for the use of 4 wards, instead of 13 wards, with 3 seats each and one at-large seat for Mpls city council elections. Then the wards could be determined with one north-south and one east-west border lines and the relevant demographic information with no room for haggling...

    (In NYC, their 51 seats could be elected with 16 similar wards and 3 at large seats and 5 sets of line-segments.)