How Regional Lists Work - Scottish Parliamentary Elections

There’s been a lot of talk about the Scottish Parliamentary Elections in 2016, particularly the Regional Vote. This uses the D’Hondt method of calculation. It’s complicated, so I’ve had a wee look and this is how you work it out:

In total, the Scottish Parliament has 129 MSPs. That’s made up of 73 constituency MSPs and 56 regional “list” MSPs.

The constituency seats are allocated through the “first past the post” method, just like in the UK General Election.

The eight regions each have seven MSPs (8x7=56) that are picked from “lists” made by each party. The seats are allocated through a method closer to proportional representation.

Take the North East Scotland region - it’s made up of ten constituencies. Now say in our hypothetical, imaginary, fictional election, the constituency results are as follows:

  • SNP 8 seats
  • Lab 1 seat
  • Con 1 seat

And in the Regional List vote (your second vote), imagine the results are as follows (in votes cast):

  • SNP 140,000
  • Lab 50,000
  • Con 40,000
  • LD 11,000
  • Grn 8,000

What happens then is we take the amount of constituency seats won by each party and add 1. That’s the First Divisor. Therefore, the party “first divisors” are as follows:

  • SNP 9 (8+1)
  • Lab 2 (1+1)
  • Con 2 (1+1)
  • LD 1 (0+1)
  • Grn 1 (0+1)

Next we divide the total votes for each party by its First Divisor and the result tells us who wins the first regional seat:

  • SNP 15,556 (140,000/9)
  • Lab 25,000 (50,000/2)
  • Con 20,000 (40,000/2)
  • LD 11,000 (10,000/1)
  • Grn 8,000 (8,000/1)

Lab have the highest number, therefore gain a regional seat, given to a politician on their list. That brings their total of MSPs to 2.

Now we go on to the Second Divisor, which, like before is calculated from the new amount of seats each party has +1

  • SNP 9 (8+1)
  • Lab 3 (2+1)
  • Con 2 (1+1)
  • LD 1 (0+1)
  • Grn 1 (0+1)

We do the total votes division again:

  • SNP 15,556 (140,000/9)
  • Lab 16,667 (50,000/3)
  • Con 20,000 (40,000/2)
  • LD 11,000 (10,000/1)
  • Grn 8,000 (8,000/1)

This time Con gains a regional seat, bringing their total MSPs to 2

See how it’s working? The Third Divisor is now:

  • SNP 9 (8+1)
  • Lab 3 (2+1)
  • Con 3 (2+1)
  • LD 1 (0+1)
  • Grn 1 (0+1)

Which means:

  • SNP 15,556 (140,000/9)
  • Lab 16,667 (50,000/3)
  • Con 13,333 (40,000/3)
  • LD 11,000 (10,000/1)
  • Grn 8,000 (8,000/1)

So Lab gain again this time. We carry on like this until all seven regional seats have been allocated.

The results in our hypothetical case end up:

  • 1st divisor - Lab +1
  • 2nd divisor - Con +1
  • 3rd divisor - Lab +1
  • 4th divisor - SNP +1
  • 5th divisor - SNP +1
  • 6th divisor - Con +1
  • 7th divisor - SNP +1

Then the final result:

  • SNP 11 MSPs (8 constituency + 3 regional)
  • Lab 3 MSPs (1 constituency + 2 regional)
  • Con 3 MSPs (1 constituency + 2 regional)
  • LD 0
  • Grn 0

That’s how you do it!

I think.