Tag Archives: voting

Best-Worst voting the answer?

With the truly appalling outcomes for Labour and Lib Dems – compared to where they need to be to be competitive in the General Election in a few weeks – maybe it is time to start thinking about electoral reform again.

Let’s start with that old trope from the LibDems – “fair votes”. Kenneth Arrow got a Nobel prize for proving there’s no such thing. Stop using the term. You decide what are the key welfare criteria you want from your system, then you can choose a voting system that delivers those (and probably not the “unimportant criteria”).

Now, we know there is a strong desire in the UK to preserve the link between “an MP” and “a constituency”. Fair enough. But the Alternative Vote – defeated in the referendum a few years ago – is not the only, or indeed perhaps even best, replacement for first-past-the-post (FPTP)

Tony Marley – co-author on the BWS book with me – has written a lot about the maths behind voting systems. People don’t realise Best-Worst Scaling works as a voting system. Plus I reckon it’d be attractive in the UK.

Here’s an example of how it might work, and deliver a different outcome to that observed in the results just published in the Local Election for the TEES VALLEY.

FIRST ROUND RESULTS:

  • CON – 40,278
  • LAB – 39,797
  • LD – 12,550
  • UKIP – 9,475

SECOND ROUND RESULTS (TOP TWO GET 2nd PREFS):

  • CON – 48,578
  • LAB – 46,400

So what happened? It’s pretty obvious most UKIP 2nd prefs went Conservative – their boost is suspiciously close to the UKIP vote. Of course we know UKIP has also poached from Labour in LEAVE-dominated northern seats, but I doubt many “kippers” put LAB as 2nd pref.

Where are the rest of the 2nd prefs?

About 7,000 are missing in action. Maybe people just refused to put a 2nd preference or gave them to fringe parties.

But I bet they knew what party they hated most.

Here’s how it might have played out under BWS:

  • LAB and LD voters encouraged to put Conservatives as “least”
  • UKIP put Labour (primarily) as “least” – some will put LD
  • CON put LAB as “least”

Result:

  • CON “lose” around 52,000 (LAB/LD) votes
  • LAB “lose” around 50,000 (CON/UKIP) votes

LIBDEM gain – or, if UKIP and some CON voters hate the LDs sufficiently (for their pro-Europe stance) even more than they hate Labour, then the “least” Labour vote leaves their net total beating the LIBDEMs. Either way the Conservatives don’t win – the UKIP/Conservative vote simply isn’t enough to offset both Labour and the LDs.

Of course with turnout around 21% a LOT more potential votes are up for grabs if people are energised to believe their vote(s) matter.

Worth thinking about.

 

 

Best-Worst Scaling in Voting

My comment to one of the links posted to today’s “Water Cooler” posting at Naked Capitalism. (Cross posted to my company blog too). The original link concerned a proposal in the US state of Maine to introduce ranked voting rather than the first-past-the-post (FPTP) that is ubiquitous in the US and UK…..the proposal sounds attractive to people, but…..

“Ranking is a double edged sword – not that I condone the current first past the post (FPTP) system endemic in the US and UK (it’s the worst of all worlds) – but people should first look at what oddballs have ended up in the Federal Senate in Australia. Plus that awful Pauline Hanson may be about to make a comeback there.

Ranking has proven very very difficult to properly axiomatize – i.e. in practice, there are a whole load of assumptions that must hold for the typical “elimination from the bottom” (or any other vote aggregation method) to properly reflect the strength of preference in the population. For instance:
(1) Not everybody ranks in the same way (top-bottom / bottom-top / top, bottom, then middle, or any other of a huge number of methods);
(2) An individual can give you different rankings depending on how you ask him/her to provide you with answers (again, ask ranks 1, 2, 3, etc,…. 9, 8, 7, etc, 1, 9, 2, 8 etc ….)
(3) People have different degrees of certainty at different ranking depths – they are typically far less sure about their middle rankings than their top and bottom choices.

Unfortunately, where academic marketing, psychology and economics studies have been done properly, these kind of problems have proven to be endemic….furthermore they often matter to the final outcome, which is worrying. It’s why gods of the field of math psych (from Luce and Marley in the 1960s onwards) were very very cautious in condoning ranking as a method.

Statement of conflict of interest: Marley and I are co-authors on the definitive textbook on an alternative method called best-worst scaling….it asks people for their most and least preferred options only. The math is much easier and I’d be very very interested to see what would have happened in both the Rep/Dem primaries if it had been used – generally you subtract the number of “least preferred” votes from the number of “most preferred” – so people like Clinton and Trump with high negatives get into trouble….”

What I didn’t say (since the work is technical) is that Tony Marley has done a lot of work in voting and has published at least one paper extolling BWS as a method of voting.