A Simple Introduction

(First published just before the Holyrood Election of May '21 using illustrations from 2016, but contains some generally applicable observations on the workings of Scotland's voting system.)

The D'Hondt system, used to allocate 56 of the 129 seats in the Scottish Parliament (commonly known as the regional ‘list' seats), must be one of the most mis-spelt and misunderstood electoral systems ever created and yet at heart it is very simple.

If you win on the constituencies, you lose on the list.

To illustrate, let's investigate the curious tale of the 'lost' list votes of the SNP in 2016.

Are you sitting comfortably? Then we'll begin.

The SNP gained a whopping 36.2% of the list votes in Lothian in 2016. How many list seats did they win? The intuitive answer is, since there are seven list seats in the region, surely they must have gained at least two, right?

Wrong.

The results are shown as below.

How did a party with comfortably the largest number of list votes win no list seats?

As the table below illustrates, because the SNP won six out of the nine constituency seats in Lothian, their list votes were immediately divided by 7 (six seats plus one).

The Conservatives, having won just one constituency seat, began with a divisor of only 2 (one seat plus one) They won the first Lothian list seat but it meant that in the second 'round' their divisor was incremented to 3.

The Greens then pipped Labour in the second round, which meant their divisor increased to 2 for the third round. And so on, until all seven additional list seats were allocated.

It was a close thing by the seventh round, but the divisor was just too much for the SNP, and they came out empty handed. This phenomenon was replicated across Scotland, the most dramatic example being in Glasgow, where 44.8% of the list vote still wasn't enough to give the SNP a single list seat.

This is the revenge of the Gods of D'Hondt on the constituency winners, relentlessly chipping away at the 'winner takes all' nature of the ‘first past the post’ constituency elections, to smooth things back to proportionality.

Even by 2016 this phenomenon was so well known that a number of the smaller independence-supporting parties sought to persuade SNP voters to vote for them on the list and not to 'waste' their list vote on the SNP. This might produce a larger independence-supporting majority in Holyrood, an important advantage when attempting to persuade an intransigent UK government to co-operate with the holding of another independence referendum. Those opposed to the idea characterised it as trying to 'game' the system. 

Both of these arguments are flawed. A vote cast with conscious intention can never be described as 'wasted'. It is an expression and record of an individual's political values. However, the idea of casting the list vote for an alternative party being a form of 'cheating' is equally absurd. The system is designed to allow such a choice, giving 'pop-up' parties a chance to get a foothold and take the country's democracy in a new direction. 

Jim Daly

Further Information

An in-depth explanation of the D’Hondt system by George Kerevan

Everything you wanted to know about D’Hondt voting system before Holyrood election | The National

D’Hondt explained with Pets!

An introduction to the D'Hondt method using Pet Elections - YouTube