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.









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