Summary: First Past the Post is unfair, but Proportional Representation creates pointless extra MPs who cost money and represent nobody. I propose the German Mixed Member Proportional system with a twist: the extra “levelling” seats are filled by phantom MPs, not real ones. These manifest as extra Commons votes for under-represented parties, giving each party the power it deserves with no need for expensive and unaccountable seat-fillers.

It’s fairly obvious by now that the UK needs some kind of proportional representation. We can no longer ignore the problem that a party can win more than half the seats with less than half the votes, or get a million votes but no seats at all. But what kind of PR should we use?

The simplest thing would be to abolish our 650 constituencies and give each party a seat for every 0.154% (or 1/650) of the vote it gets. But then we lose the local representation we cherish so dearly. We’d have 650 MPs all living only in London, blind to the needs of those outside the M25. All of them would be chosen by the party, not the people – this makes it almost impossible to get rid of unpopular individuals in major parties. Nobody would feel connected to a single one of them, and most would be totally unknown to the people who supposedly elected them. Nobody would have a responsibility to stand up before the leaders of the nation and defend the interests of John o’Groats or Nether Wallop. How would you choose who to write to about local issues? And why would any of them bother to listen when no locality can vote him out by itself? When everyone is responsible, no-one is responsible – we’d have the tragedy of the commons in the House of Commons.

This thought-experiment illustrates the dilemma of Proportional Representation: you can’t have accountability if there’s more than one winner per area, but you can’t have proportionality if there are no prizes for second place. Going halfway and dividing the country into multi-member regions (as in Norway and the Scottish regional seats) is an imperfect compromise, incorporating the problems of both systems no matter where you draw the lines.

The non-locality problem can be solved with split levels. The simplest way is to have half the seats as single-member constituency seats, like we have now, and half of them as national or regional “levelling” seats. This so-called “Mixed Member Proportional system” (MMP) is used in Germany and New Zealand (ignoring some complications about special Maori seats). Under this system, the UK’s Green Party, which got 1% of the vote but only one seat out of 650, would get an extra 12 levelling seats to bring its representation in Parliament into line with its share of the vote: 13 out of 1300.

Numerically, this is entirely fair. But you’ll have noticed the problem already – there are now twice as many MPs as before. MPs have to be paid a salary and reimbursed for their expenses. A 100% cost increase is the last thing we want after the recent expenses scandal and the financial crisis. There also has to be space for them in the House, which we don’t have – a new building in Central London would cost a fortune and be devoid of the beauty and historical magic of the current Houses of Parliament. Even if we threw out the Lords to make room for the extras, they wouldn’t all be in the same debating chamber.

To get the numbers back down from 1300 to 650, we have to halve the number of constituencies by merging each of them with one of its neighbours. This is no problem in cities, but rural constituencies would become unmanageably large. The MP for Orkney and Shetland has a difficult enough job getting around his constituency without us giving him Caithness, Sutherland and Easter Ross to worry about. If we leave the rural constituencies alone and merge the city ones, the countryside ends up grossly over-represented. And even if we could somehow get around these issues, we are still left with the problem that half our MPs are party moguls the people don’t know. And it’s still impossible to get rid of unpopular politicians: in 1999, New Zealand’s Michael Cullen suffered a huge defeat in his constituency, but stayed in Parliament as an “extra” because he was high up on the party list.

So is PR forever condemned to be a “least worst” option, unable to overcome the problems of unfairness on the one hand and unaccountability on the other? I think not, and the reason is arrestingly simple: all the problems of First Past the Post stem from the fact that one seat equals one vote in the House of Commons. No allowance is made for the fact that each Liberal Democrat MP has 120,000 popular votes behind him while each Conservative MP only has 35,000. The former ought to count for 3.5 times as much as the latter, but each of them counts exactly once when the division bell sounds.

If we dispense with the “one MP, one Commons vote” notion, we can achieve proportional fairness without doubling the size of the House, without disadvantaging rural areas, and without forcing people to elect total strangers. But how could this work? Consider the German system: 299 constituency MPs elected by First Past the Post, and 299 extras to level the playing field. The extras are literally just there to make up the numbers. So why do they need to actually exist? Why not have “phantom MPs” who always vote in line with the real ones? These could make up the numbers just as well as the flesh-and-blood extras do in Germany, but we wouldn’t have to pay for their salaries, travel, food, dishwashers, cleaners and mortgages, because a phantom needs none of these things. Instead of living in expensive second homes, they can haunt the House of Commons in the form of extra “ghost votes” for the real-life MPs of their party.

This also gives us a solution to the current problem that you can’t vote for a minority party if there’s no candidate for your constituency. In the recent election, nearly half the country couldn’t vote Green even if they wanted to, because there wasn’t a local candidate. Minor parties simply can’t afford to spend their limited resources contesting hundreds seats they know they can’t win. The Greens got 1% overall, but if they’d had 650 candidates instead of only 338, they might have got twice that. This is another way in which First Past the Post punishes smaller parties – not only does it stop them gaining seats, but it stops them even trying in the first place.

The usual MMP solution to this problem is to give people two votes, one for the party which determines the overall allocation of seats, and one for the constituency MP. We could do this: the advantage is that you can, if you want, vote for different parties with each vote, which is useful if you like a party but hate its local candidate. But the disadvantage is that this confuses people – in Scotland, where a similar system operates for the devolved parliament, the 2003 Scottish Social Attitudes Survey showed that most people misunderstood the basics of the system. The alternative, which works for my proposal but not for existing MMP systems, is to list all parties on the ballot paper, and simply leave the “name” field blank for those who aren’t fielding a candidate in that constituency, allowing people to vote for a “phantom”. This preserves the simple and well understood single-vote system we currently have. As both work with my system, we can pick either according to preference.

There are five issues still to be resolved: distribution, overhangs, parties with no constituency MPs, independents, and MPs who change parties or go independent mid-term. I will deal with each of them in turn. This is going into the fine detail, though, so anyone who's not that interested in how I would work out the kinks can just skip ahead to the conclusion.

Distribution

Now that we have these extra Commons votes, we need to work out a fair way of distributing them. Leaving them all in the hands of the party leader would give too much power to his or her constituency: the inhabitants of Witney, Kirkcaldy & Cowdenbeath and Sheffield Hallam (or wherever the main party leaders happen to be from) would have hundreds more Commons votes than the people down the road. My suggestion is to rank each MP in order of the percentage majority they got at home, put an extra “leader’s hat” at the top (leaving the actual leader in place), and give out the ghost votes one by one in that order until they run out. This allows MPs to use their ghost votes when local issues bring him into conflict with the party view and they want to dissent. The “leader’s hat” is there to take account of the fact that many people vote based on their opinion of the party leader rather than their local candidate – the actual leader would then get these ghost votes in addition to his own, and if he steps down as leader, the hat passes on. But this is a minor detail – it wouldn’t make a huge difference if we did something else, such as allowing fractions of votes.

Overhangs

Overhangs occur when a party wins more constituency MPs than its overall share of the vote deserves. For example, on 6 May the DUP won eight seats, but according to its overall share of the vote it should have seven (out of 1300). Since we can’t give it -1 ghost votes, or sack any of its MPs, it is overrepresented. Overhangs exist in any MMP system and are mostly just tolerated. Germany actually creates even more extra seats when this happens: currently there are 24 overhang seats as well as the 598 it’s supposed to have. Assuming there is a mathematically fair way to do it, this may be the best option in my system since the extras cost nothing to create. Otherwise we could simply ignore the problem and live with the overhang.

Ghosts without bodies

A bigger problem is parties which deserve some ghost votes but don’t have any real MPs to give them to. UKIP got no seats but under MMP would get 41 extras. Who is to wield these 41 ghost votes? We can reduce, but not eliminate, the possibility of this problem occurring with a threshold – a rule whereby a party must get, say, 4% of the overall vote before it can have any ghosts. This has the advantage of keeping extremists out, but this is arbitrary and reintroduces some of the unfairness of First Past the Post (discriminating against small parties). It also creates overhangs when small parties do manage to win a seat despite having less than the threshold overall – a party with 3.9% of the vote concentrated in a small area can win seats, while a party with the same percentage of the vote spread across the country gets nothing. And it’s still possible for a party to get more than the threshold but no seats.

My preferred solution is to have no threshold, and allow the leaders of these parties to sit in the House of Commons as “observer members”. They (or rather, their ghosts) can vote on motions and bills but cannot speak (on pain of ejection) or propose bills. This preserves the advantage of keeping disruptive extremist voices quiet while still allowing the section of the public which voted for them to express its view on bills proposed by the others. They would undoubtedly try to cut deals with MPs to offer their support in return for proxy proposals, but at least they are likely to be presented in a less inflammatory manner and are no more likely to succeed. We can avoid disgraceful incidents of outspokenness, such as when Nigel Farage hurled abuse at European President Herman van Rompuy in the EU Parliament, without denying our sizeable Eurosceptic population a fair chance at blocking new EU treaties. Also, if we didn’t disenfranchise these parties, they wouldn’t need to be so loud-mouthed and obnoxious in the first place. There are doubtlessly other potential ways around the problem, but I believe this suggestion at least presents one workable option.

Independents and one-man parties

Another problem is what to do about independents. We could simply treat them as one-man parties – after all, it’s unlikely that anybody would get enough votes within a single constituency to get an additional ghost vote. But it could lead to overrepresentation – if an independent persuaded nearly everyone to vote tactically for him or her, that constituency would have two Commons votes rather than one. The promise of double representation might persuade them to do this, but it seems unfair to the people next door. There’d also be no reason for individuals not to clutter up the ballot papers by forming one-man parties – at least that way they’d have a chance of picking up votes from other places. We’d have 100 parties on every ballot paper in the country, instead of one extra name in 100 constituencies.

My solution is to have a much higher deposit for parties than for independents. This will keep the number of frivolous parties to a minimum. If desired, we could simply say that independents can’t have ghost votes, but some would argue this is both unfair and hardly necessary – if they can win a seat with 95% of the vote, they probably deserve the ghost. However, other solutions may well be preferred, and this can be looked at in more detail.

Changing sides

This leaves only the problem of MPs who change parties or go independent between elections. It’s already unfair that you can vote in an MP of one party only to see him change sides, but it’s even worse if he commands four ghost votes earned by his former party, not himself. One solution is to force the turncoat to leave the ghosts behind and redistribute them within the party. This would act as a deterrent, but could unfairly penalise MPs who have legitimate reasons for defecting. Also, in a single-vote system it would mess up the numbers – how are we to know how many votes the defector got because people liked him personally, and how many because they liked his party? The same problem occurs if you try to redo the calculation of ghosts from scratch. Does the defector goes to the back of the queue for ghosts in the new party even if he won by a landslide? If so, he’s penalised again; but if not, he might be stealing party votes. In a two-vote system, this isn’t as problematic as the candidate vote and the party vote are separate, but it’s still likely that the candidate vote will have been influenced by party considerations.

Fortunately, there’s another solution which has already been proposed for our current system – hold a by-election whenever an MP changes parties or goes independent. Then voters can make a fresh decision with full knowledge of the new facts, and the ghosts can be redistributed on up-to-date figures. The disadvantage is the expense. We would have to decide whether this was a price worth paying.

Conclusion

The “Elect One, Get One Free” system combines the advantages of First Past the Post and MMP while shedding the problems of both. It is entirely fair and preserves local connections and accountability. The few problems are minor and solvable in several ways. It can be implemented at practically no extra cost without substantially changing the number of MPs or radically changing the size of constituencies. I firmly believe this should be on the electoral reform table along with existing systems.