What if the list seats weren’t split into regions?

As you are no doubt aware, the Welsh Assembly elects members using the d’Hondt method of additional members. Essentially the list seats are preferentially allocated to parties who have fewer constituency seats than is proportional to their vote. Here’s a longer explanation. But rather than being allocated across Wales as a whole, the list AMs are allocated separately in five regions – North Wales, Mid and West Wales, South Wales West, South Wales Central, and South Wales East.

It’s not clear why we do this. The constituency AMs already represent specific areas and the list AMs are supposed to compensate for the lack of proportionality in the first-past-the-post system.If this is the case, why not elect them across Wales as a whole?

Under the existing regional list system, the AMs were allocated as follows:

  • Labour: 2
  • Plaid Cymru: 6
  • UKIP: 7
  • Conservatives 5

What if we ran the system over Wales, ignoring regions? The results look like this:

  • Labour: 0 (from 319,196 list votes!)
  • Plaid Cymru: 5 (from 211,549 list votes)
  • UKIP: 7 (from 132,138 list votes)
  • Conservatives: 3 (from 160,846 list votes)
  • Liberal Democrats: 2 (from 65,504 list votes)
  • Abolish the Welsh Assembly Party: 2 (from 44,286 list votes)
  • Greens: 1 (from 30,211 list votes)

A few things jump out:

  1. A greater number of parties get AMs, including rather surprisingly the Abolish the Welsh Assembly Party.
  2. Labour get no list AMs at all, despite getting over 32% of the list vote.
  3. Only one party with AMs would stand to profit from such a change (the Lib Dems, who would get two list AMs).
  4. UKIP do exactly the same under either system.

At the end of the day, it depends on what you want a voting system to do. Proportionality, ties to locality, support for strong governments, and simplicity (as my R code to run the d’Hondt process will attest) are somewhat mutually exclusive. The system as it stands seems relatively friendly to Labour, who of course set the assembly up. That said, it would seem perverse for them to get no list seats at all from a full 32% of the vote. What is clear though is that for better or worse, the regional character of the current list system acts as a filter on smaller parties, to the advantage of the larger parties. Which  is why I would be surprised if they adopt this system any time soon.

Carwyn Jones – The lucky general?

That Carwyn Jones is a lucky general is fast becoming a cliche of Welsh political punditry. Richard Wyn Jones of Cardiff University covers it here in the Guardian and Vaughan Roderick mentioned it a few times on S4C’s coverage and on his BBC Radio Wales programme. It certainly feels right – the numbers in close elections just always seemed to break Labour’s way. Llanelli, Cardiff Central, and the Vales of Glamorgan and Clwyd went to Labour on pretty slender margins.

Then again, Labour just won a lot more constituency seats than anyone else – 27 against just 13 for other parties. This being the case, it would be weird if Labour’s share of marginal seats wasn’t also higher than the other parties. If Labour were absolutely sweeping the board (a la the SNP in the 2015 General Election), we might expect all their opponents’ seats to be marginal but that’s not the case.

I’ve plotted the winning majority (on the y-axis) against Labour’s share of the vote (on the X-axis). The colour of the constituency’s name shows which party won it.


There’s certainly a bunch of seats which Labour won on fairly small majorities: Llanelli, the two ‘Vale of’ seats, Cardiff West. Then again, they also racked up huge majorities in Ogmore, Swansea East, and Cardiff South.

To put some numbers to this, I looked at the mean majorities by party:

  • Labour:3860
  • Plaid:5774
  • Conservative:3601
  • Liberal Democrats: 8170 – Although this value is not so much a mean as the majority of their sole seat, so not very representative.

So based on this, one could argue that it is in fact Andrew RT Davies who is the lucky general, whose Conservatives squeaked home in the most seats! Indeed the Conservatives’ majorities were consistently lower, whereas Labour’s ran the full range.

I also ran some simple statistical tests comparing the majorities of Labour seats to non-Labour seats. A bootstrapped t-test found that the difference between Labour (3860) and non-Labour (4955) seats  was no larger than you would expect by chance. The number of constituencies we have to analyse is fairly small and there are probably cleverer ways of looking at this question (perhaps looking closer at that apparent cluster of constituencies in the bottom right of the plot), but it suggests that there isn’t a major difference.

So on the surface of things, it is not clear that Labour are any luckier in this way than their rivals. There are of course other ways in which Carwyn Jones may have been lucky – perhaps the Tata crisis gave him a chance to present himself as statesmanlike, perhaps Conservative divisions on Europe hurt them, perhaps UKIP were distracted by the unpcoming referendum.. But in this narrow sense of luck, the numbers don’t seem to bear it out.









Hello world

In the small hours of election night, addled by lack of sleep, I decided I’d like to start a blog on Welsh politics. Here it is (I’ll get better at this I swear). It’s going to be one of those, oh so modern, data journalism endeavours because I’m that way inclined.

In the interest of transparency I’m centre-left and have voted Plaid Cymru, Labour, and Liberal Democrat in the three UK general elections I’ve been old enough to vote, which I suppose makes me a floating voter. I’m originally from London but moved to North Wales for university and went native (which explains the Plaid Cymru thing). I’m not planning on writing in a partisan way, but that’s easier said than done.

Anyhow, thank you for reading. Again, I’ll definitely get better at this. Comments welcome.