There are 60 candidates elected to represent Wales in the elections. 40 through a system similar to the Westminster election, where the candidate with the most votes wins. This happens even if most people didn’t vote for them.
We elect a further 20 candidates through a second ballot, where you choose a party only. The regional vote is not first past the post, using proportional representation known as the Additional Member System. This helps to overcome the imbalance often associated with first-past-the-post elections. The ballot lists names representing each party in the region, and a vote for a party is a vote to make more of their candidates into Members of the Senedd. There are five regions of Wales with four candidates elected in each.
Constituency vote
First past the post favours larger and traditional parties. Smaller parties and independents struggle to get enough support to win outright, even though they could get a significant percentage of the vote.
Regional vote
Each region in Wales comprises eight constituencies. A count of the first past the post ballot papers identifies the eight winners of the constituency vote.
Following this, a count of the second ballot papers identifies the four remaining candidates for the region. Depending on how many seats a party wins on the first ballot, the additional members allocated from the regional list aims to make the Welsh Parliament match how the country voted. Let me explain as simple as I can.
Regional seat allocation
Let us assume four parties are standing, Party A, Party B, Party C and Party D. The results come in for the 8 seats in the region and we get:
Constituency seats
Party A — 5 seats
Party B — 2 seats
Party C — 1 seat
Party D — 0 seats
Let’s assume the following outcome of the regional ballot:
Party A — 36%
Party B — 28%
Party C — 23%
Party D — 13%
Parties with seats from the first ballot have their regional vote discounted, based on how many seats already won. We know this as the D’Hondt method to ensure parties do not win ‘twice’. Four rounds of discounting take place until we allocate the four regional seats.
Round One
The regional vote is divided by the number of seats already won (+1). So if you win one seat, you get divided by two (1+1). In this example, we get:
Party A — 6% (36 divided by 6)
Party B — 9.3% (28% divided by 3)
Party C — 11.5% (23% divided by 2)
Party D — 13% (13% divided by 1)
After round one, you can see Party D has the most votes so gets allocated the first regional seat and their vote discounted for round two.
Round Two
Party A — 6% (36 divided by 6)
Party B — 9.3% (28% divided by 3)
Party C — 11.5% (23% divided by 2)
Party D — 6.5% (13% divided by 2)
After the second round, you can see Party C has the most votes so gets allocated the second regional seat and their vote discounted for round three.
Round Three
Party A — 6% (36 divided by 6)
Party B — 9.3% (28% divided by 3)
Party C — 7.7% (23% divided by 3)
Party D — 6.5% (13% divided by 2).
After the third round, you can see Party B has the most votes so gets allocated the third regional seat and their vote discounted for round four.
Round Four
Party A — 6% (36 divided by 6)
Party B — 7% (28% divided by 4)
Party C — 7.7% (23% divided by 3)
Party D — 6.5% (13% divided by 2).]
After the fourth round, you can see Party C has the most votes so get allocated the final regional seat.
So the total seats for the region would be
Party A — 5
Party B — 3
Party C — 3
Party D — 1
Party D failed to win any seats in first past the post but gets fair representation in the Senedd by getting 12.5% of the vote and having one seat. This means every vote matters for the elections on May 6th.
Jamie Jenkins
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Jamie Jenkins is the former Head of Health Analysis and Labour Market Analysis at the Office for National Statistics. Jamie has been providing daily data updates for the public on the Covid-19 pandemic the past year and has won awards from the Royal Statistical Society and United Nations for the presentation of data. He also worked at the BBC advising journalists on data over a General Election period, helping them challenge politicians