threshold proportional representation

stuff that goes nowhere else

The current scheme — First Past The Post — tends to magnify differences in national party vote. This gives stronger Commons majorities but doesn't represent the peoples' will i.e. numbers of MPs proportional to the votes for their parties.

Threshol Proportional Representation (TPR) is an idea for how to get proportional represention with these features:

1. keeps MPs representing their constituency.
2. Multi-member STV needs at least 4 seats to be merged, and doesn't give minority parties their due.

The threshold pr scheme:

1. has the same candidature and voting system as currently, it's the counting that's different.
2. a majority (percentage difference between 1st and 2nd places) threshold is decided which must be met to win a seat, on the basis that it shouldn't be possible to win a seat by 1 vote or anything like it; the examples below suggest 20% would be about right.
3. those that already pass the majority threshold are won outright by their 1st place candidates;
4. those that don't pass the majority threshold go into the transfer phase:
   1. starting with the seat with the greatest majority not yet won
   2. take the 1st place candidate; work out how many extra votes would be needed to meet the majority threshold
   3. transfer votes from candidates for the same party starting with the seat with the least majority, on the basis that that seat is the least decided about who they want and so will be the least annoyed about having the result affected by this scheme; if the transfer would leave that seat with no candidate with any votes then go on to the next least. The effect of this is to move votes for the major parties away from marginal seats leaving the minority parties to contest them between themselves.
5. if any seats are left with not enough transferable votes to meet the majority threshold then they are winnable by a simple majorty.
6. extra rules for specific cases:
   1. 1st place candidates without a party, i.e. independents, can win by a simple majority.
   2. candidates who lose their deposit (fewer than 5% of the votes in the constituency) can't have votes transferred to them nor win by a simple majority in the last phase, but their votes can be transferred to other candidates in the same party.
   3. a voter should be able to say that their vote isn't transferable.

1. depending on the choice of majority threshold value the proportion of votes to seats won is closer than with simple majority counting.
2. there is no sense of arbitrariness from the possibility of someone winning by a handful of votes.
3. all candidates represent a particular seat, unlike most pr schemes which involve lists of extras decided centrally. We don't like it when a candidate doesn't come from their constituency, let alone when they've been parachuted in from Westminster, still less having lists of party hacks to make up the numbers.
4. the government majority (number of seats more than all non-government seats) is reduced but still, mostly, effective. Other pr schemes can produce wafer-thin majorities leaving a third, possibly extreme, party holding the balance of power.
5. national but minority parties have a good chance of gaining representation, improving the colourfulness of Parliament and encouraging disaffected voters to turn out.
6. there is the possibility, in the event of a hung Parliament (no party having a majority), of changing the majority threshold value after the first count so that the government majority is increased to some workable number, thus avoiding the effort and cost of a second election. The Act could say "the majority threshold shall be N% except in the case of a Government majority of fewer than M when the threshold shall be adjusted accordingly" or similar.

1. the proportion of votes to seats is not perfect. The scheme is a compromise between improving the pr and avoiding the usual problems with pr schemes.
2. some marginal constituencies will likely end up wth MPs regarded as fringe. It will be up to the minority parties to show they are not fringe nutters.
3. not everyone's vote will be counted in the constituency they voted in.
4. it's more complex to think about than simple majority counting, particularly as it is essentially a compromise between competing problems.
5. if the turn-out improves significantly then it's likely the overall pattern of voting will be changed, to what we don't know.
6. the election night count can't be completed until all the seats are in. However, good estimates can be made and it might make it less unexciting.

Here are re-runs of the last few UK General Elections with what would have happened under threshold pr with various majority thresholds. In general the higher the threshold the lower the government majority and the more seats go to minority parties, in fact the transition is really smooth. The regional parties tend not to be much affected since their vote is very concentrated geographically.

party	votes	fptp seats	tpr @ 10% seats	tpr @ 15% seats	tpr @ 20% seats	tpr @ 25% seats	tpr @ 30% seats
Labour	9,552,436 35.2%	355 55.0%	349 54.0%	343 53.1%	338 52.3%	327 50.6%	319 49.4%
majority		64	52	40	30	8	-8
Conservative	8,784,915 32.4%	198 30.7%	204 31.6%	207 32.0%	200 31.0%	194 30.0%	187 28.9%
Liberal Democrats	5,985,454 22.0%	62 9.6%	62 9.6%	63 9.8%	72 11.1%	90 10.4%	101 15.6%
UKIP	605,973 2.2%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	1 0.2%
Scottish Nationalists	412,267 1.5%	6 0.9%	5 0.8%	6 0.9%	7 1.1%	7 1.1%	7 1.1%
Green	283,414 1.0%	0 0.0%	0 0.0%	0 0.0%	2 0.3%	2 0.3%	2 0.3%
Democratic Unionists	241,856 0.9%	9 1.4%	9 1.4%	9 1.4%	9 1.4%	9 1.4%	9 1.4%
Plaid Cymru	174,838 0.6%	3 0.5%	4 0.6%	5 0.8%	5 0.8%	4 0.6%	7 1.1%
Sinn Fein	174,530 0.6%	5 0.8%	5 0.8%	5 0.8%	5 0.8%	5 0.8%	4 0.6%
SDLP	125,626 0.5%	3 0.5%	3 0.5%	3 0.5%	3 0.5%	2 0.3%	2 0.3%
Ulster Unionists	127,414 0.5%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	2 0.3%	3 0.5%
Independent	122,416 0.5%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Respect	68,094 0.3%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
KHHC	18,739 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Speaker	15,153 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%

party	votes	fptp seats	tpr @ 10% seats	tpr @ 15% seats	tpr @ 20% seats	tpr @ 25% seats	tpr @ 30% seats
Labour	10,724,953 40.7%	412 62.5%	410 62.2%	406 61.6%	400 60.7%	392 59.5%	383 58.1%
majority		165	161	153	141	125	107
Conservative	8,357,615 31.7%	166 25.2%	166 25.2%	166 25.2%	164 24.9%	161 24.4%	158 24.0%
Liberal Democrats	4,814,321 18.3%	52 7.9%	53 8.0%	57 8.6%	65 9.9%	75 11.4%	88 13.4%
Scottish Nationalists	464,314 1.8%	5 0.8%	6 0.9%	6 0.9%	6 0.9%	6 0.9%	6 0.9%
Ulster Unionists	216,839 0.8%	6 0.9%	6 0.9%	6 0.9%	6 0.9%	5 0.8%	5 0.8%
Plaid Cymru	195,893 0.7%	4 0.6%	4 0.6%	4 0.6%	4 0.6%	5 0.8%	4 0.6%
Democratic Unionists	181,999 0.7%	5 0.8%	5 0.8%	5 0.8%	5 0.8%	5 0.8%	5 0.8%
Sinn Fein	175,933 0.7%	4 0.6%	4 0.6%	4 0.6%	4 0.6%	4 0.6%	3 0.5%
SDLP	169,865 0.6%	3 0.5%	3 0.5%	3 0.5%	3 0.5%	3 0.5%	3 0.5%
Alliance Party of NI	28,999 0.1%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	1 0.2%	1 0.2%
KHHC	28,487 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Speaker	16,053 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%

party	votes	fptp seats	tpr @ 10% seats	tpr @ 15% seats	tpr @ 20% seats	tpr @ 25% seats	tpr @ 30% seats
Labour	12,653,431 41.7%	385 59.3%	383 59.0%	380 58.6%	376 57.9%	370 57.0%	364 56.1%
majority		121	117	111	103	91	79
Conservative	9,425,095 30.5%	161 24.8%	160 24.7%	156 24.0%	150 23.1%	145 22.3%	141 21.7%
Liberal Democrats	5,165,578 16.7%	44 6.8%	47 7.2%	54 8.3%	63 9.7%	70 10.8%	79 12.2%
Labour (Co-op)	634,550 2.1%	25 3.9%	25 3.9%	24 3.7%	24 3.7%	24 3.7%	23 3.5%
Scottish Nationalists	608,958 2.0%	6 0.9%	6 0.9%	6 0.9%	6 0.9%	6 0.9%	6 0.9%
Ulster Unionists	235,145 0.8%	9 1.4%	9 1.4%	9 1.4%	8 1.2%	8 1.2%	8 1.2%
SDLP	188,609 0.6%	3 0.5%	3 0.5%	3 0.5%	4 0.6%	4 0.6%	3 0.5%
Plaid Cymru	160,292 0.5%	4 0.6%	4 0.6%	4 0.6%	4 0.6%	4 0.6%	4 0.6%
Sinn Fein	125,568 0.4%	2 0.3%	2 0.3%	2 0.3%	2 0.3%	2 0.3%	3 0.5%
U Democratic Unionists	84,026 0.3%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Independent	61,996 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Labour (Independent)	46,520 0.2%	2 0.3%	2 0.3%	2 0.3%	2 0.3%	2 0.3%	2 0.3%
Conservative (Labour)	24,282 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Speaker	23,969 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Conservative (Independent)	23,570 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Conservative (Independent Conservative)	22,888 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Independent Conservative	20,279 0.1%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	0 0.0%	1 0.2%
Labour (Independent Labour)	18,525 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
UKUP	12,817 0.0%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%

party	votes	fptp seats	tpr @ 10% seats	tpr @ 15% seats	tpr @ 20% seats	tpr @ 25% seats	tpr @ 30% seats
Conservative	14,093,007 41.9%	335 51.5%	328 50.5%	323 49.7%	318 48.9%	309 47.5%	302 46.5%
majority		20	6	-4	-14	-32	-46
Labour	11,560,484 34.4%	271 41.7%	271 41.7%	270 41.6%	268 41.2%	263 40.5%	259 39.8%
Liberal Democrats	6,010,310 17.9%	20 3.1%	26 4.0%	33 5.1%	40 6.2%	53 8.2%	62 9.5%
Scottish Nationalists	629,564 1.9%	3 0.5%	4 0.6%	3 0.5%	4 0.6%	5 0.8%	6 0.9%
Ulster Unionists	271,049 0.8%	9 1.4%	9 1.4%	9 1.4%	9 1.4%	9 1.4%	9 1.4%
SDLP	187,012 0.6%	4 0.6%	4 0.6%	3 0.5%	3 0.5%	3 0.5%	3 0.5%
Plaid Cymru	150,032 0.4%	4 0.6%	4 0.6%	4 0.6%	3 0.5%	3 0.5%	4 0.6%
Democratic Unionists	103,039 0.3%	3 0.5%	3 0.5%	3 0.5%	3 0.5%	3 0.5%	3 0.5%
Sinn Fein	78,291 0.2%	0 0.0%	0 0.0%	1 0.2%	1 0.2%	1 0.2%	1 0.2%
Ulster Popular Unionists	19,305 0.1%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%	1 0.2%

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to be mailed when changes occur.

Patrick Herring, except where otherwise acknowledged eg. in "alt" clauses.