By LightningMinion, Devolution Correspondent

Welsh Labour remain the largest party

WPXII saw Welsh Labour remain the largest party in the Senedd with 23 seats, 8 seats short of an overall majority. Plaid Cymru remained as the second largest party, winning 18 seats, and the Welsh Conservatives are close behind in third place, winning 16 seats. Independent candidate /u/Maroiogog won 2 seats, whereas the Serbian People’s Union of Pontypridd won 1 seat even though they received more votes than /u/Maroiogog across both constituencies.

Party	Previous election result	Pre-election polls (change with WPXI)	Election result (change with WPXI)	Change with pre-election polls
Welsh Labour	21 seats, 34.18%	28 (+7) seats, 46.14% (+11.96)	23 (+2) seats, 39.13% (+4.95)	-5 seats, -7.01%
Plaid Cymru	17 seats, 27.65%	20 (+3) seats, 33.27% (+5.62)	18 (+1) seats, 30.13% (+2.48)	-2 seats, -3.14%
Welsh Conservatives	12 seats, 20.84%	12 (nc) seats, 19.76% (-1.08)	16 (+4) seats, 26.68% (+5.84)	+4 seats, +6.92%
Maroiogog (Independent)	Didn't exist	0 seats, 0.55%	2 seats, 1.90%	+2 seats, +1.35%
Serbian People's Union of Pontypridd	Didn't exist	0 seats, 0.28%	1 seat, 2.15%	+1 seat, +1.87%

Figure 1: a table showing the WPXII election result.

Welsh Labour and Plaid Cymru underperformed their polling just before the election, while the Welsh Conservatives overperformed their pre-election polling. /u/Maroiogog and the SPUP won seats in the Senedd, even though their pre-election polling suggested they may fail to do so.

The Independent’s prediction was accurate

Party	Election result (change with WPXI)	Prediction (99.7% confidence interval)	Difference between prediction and actual result	Error in vote share
Welsh Labour	23 (+2) seats, 39.13% (+4.95)	(24 ± 5) seats, (39.88 ± 9.12)%	-1 seat, -0.75%	0.25σ
Plaid Cymru	18 (+1) seats, 30.13% (+2.48)	(18 ± 5) seats, (29.70 ± 7.52)%	no change in seats, +0.43%	0.17σ
Welsh Conservatives	16 (+4) seats, 26.68% (+5.84)	(14 ± 7) seats, (24.07 ± 10.90)%	+2 seats, +2.61%	0.72σ
Maroiogog (Independent)	2 seats, 1.90%	(2 ± 2) seats, (3.45 ± 3.08)%	no change in seats, +0.43%	1.09σ
Serbian People's Union of Pontypridd	1 seat, 2.15%	(2 ± 2) seats, (2.89 ± 2.71)%	-1 seat, -1.30%	1.27σ

Figure 2: a table comparing the predicted and the actual election results. σ represents the standard deviation in the prediction. The deviation given in the prediction, which was a 99.7% confidence interval, represents 3 standard deviations.

Figure 3: a graph showing the Independent’s predicted probability distributions of seats won by each party, and the actual number of seats won. The solid lines represent the normally distributed probability distributions, whereas the dots represent the actual number of seats won by the party.

Welsh Labour and the SPUP were overestimated by 1 seat each and the Welsh Conservatives were underestimated by 2 seats, but these errors are within the margin of error. Plaid Cymru and /u/Maroiogog’s predicted number of seats were spot on. As shown in figure 2, the actual vote shares of the big parties are within one standard deviation of the predicted vote share, while for the minor parties and independents, it’s within 2 standard deviations. The meaning of this is that the prediction was accurate.

Next First Minister likely to be from Welsh Labour

The Independent believes that 3 possible coalitions could form: a continuation of the existing grand coalition between Welsh Labour and the Welsh Conservatives, a left-wing coalition between Welsh Labour and Plaid Cymru, and a grand coalition between the Welsh Conservatives and Plaid Cymru.

The incumbent governing coalition increased its majority from 6 seats to 18 seats. Welsh Labour leader /u/lily-irl and the co-leaders of the Welsh Conservatives, /u/t2boys and /u/PoliticoBailey, have confirmed that they have reached out to each other to begin negotiations for a new coalition agreement between the 2 parties. In a press release, /u/lily-irl said that, though “substantial differences exist in policy” between the 2 parties, she believes they can negotiate a coalition agreement. A press release from the Welsh Conservatives stated that their preliminary analysis of the Welsh Labour manifesto suggests “large overlap” between the aims of the 2 parties, and also stated that where 2 parties disagree on a policy, the disagreement isn’t sufficient to make governing “impossible.”

/u/lily-irl also confirmed that she has reached out to Plaid Cymru to negotiate a coalition agreement with them for a left-wing coalition government. The 2 parties have served together in government previously, and are currently in a coalition at Westminster.

Both of the possible coalitions proposed above would see Welsh Labour retain the post of First Minister. Any coalition deal which would see Welsh Labour deprived of power and sent into opposition would require the Welsh Conservatives and Plaid Cymru to work together. However, the Welsh Conservatives have suggested that this is unlikely to happen: a press release from the party stated that they “don’t see a path for a deal with Plaid”. The press release went on to criticise Plaid Cymru for not publicly stating why they had opposed the incumbent coalition’s budget, which was drafted by Welsh Conservative Finance Minister /u/t2boys, and suggested they would only be open to talks between the 2 parties for a coalition agreement if Plaid Cymru explained why they opposed the budget. Due to this and the ideological differences between the 2 parties, the Independent considers a Plaid Cymru-Welsh Conservatives coalition to be unlikely.

Therefore, the next Welsh Government is likely to be led by a Welsh Labour First Minister. It will be up to Welsh Labour to decide whether they wish to govern with the Welsh Conservatives or with Plaid Cymru, suggesting that they are the kingmakers following WPXII.