The Associated Press"s coverage of Northern Ireland"s Legislative Assembly elections on March 9 drew my attention. The first line of its latest newswire reads:

Hard-liners on both sides won Northern Ireland's election, final results confirmed Friday, setting the stage for a major diplomatic push to forge a Catholic-Protestant administration of bitter enemies.

The Democratic Unionists Party (DUP), which is heavily Protestant, led the elections. Sinn Fein, which is comprised of Irish nationalists, came in second. The article also explains how moderate parties, such as the Social Democratic and Labour Party (SDLP) and the Ulster Unionists Party (UUP), lagged behind.

How did Northern Ireland"s system of proportional voting contribute to this outcome? Did it help elect more hard-line party candidates or more moderate party candidates?

Northern Ireland uses a system of proportional voting known as choice voting. Choice voting, known as single transferable voting (STV) in Northern Ireland, allows voters to rank their candidates in order of preference. Each winning candidate has to garner a threshold quota of votes. This is achieved through rounds of counting that minimize wasted votes by transferring winners' surplus and votes for losers. If a voter"s first choice candidate is not elected, his or her vote is transferred on to his or her second or third choice candidate. Here are the results of the 2007 elections:

Party	Seats	% of Seats	% of First Choices	Deviation From Proportionality
DUP	36	33.3%	30.1%	+3.2%
SF	28	25.9%	26.2%	-0.3%
UUP	18	16.7%	14.9%	+1.8%
SDLP	16	14.8%	15.2%	-0.4%
AP	7	6.5%	5.2%	+1.3%
GP	1	0.93%	1.7%	-0.77%
PUP	1	0.93%	0.6%	+0.33%
OTH	1	0.93%	3.2%	-2.27%

As you can see, the percentage of seats won was roughly proportional to the percentage of first choices. The DUP won 30.1% of the total first choices, and it received 33.3% of the seats in the Legislative Assembly. The SDLP won 15.2% of first choices and 14.8% of the seats.

Now let"s see what would have happened if Northern Ireland used a less proportional, limited voting system (a.k.a. "one vote" or single non-transferable vote). There are 18 districts in Northern Ireland, and each elects 6 assembly members to represent them. Under limited voting, the 6 candidates who received the most votes each in each district would have been elected. Let"s assume that if the elections were conducted in this manner, the electorate would have voted in the same way as their first choices under choice voting. There is an important caveat. Voters vote more strategically in less proportional systems because they're aware of the increased chances their votes will be wasted. Thus they vote their fears, the "lesser of evils," instead of their desires. But let"s make the assumption for the sake of argument. Here"s what the election would have looked like if limited voting were used:

Party	Seats	% of Seats	% of Popular Vote	Total Seat Deviation	Deviation from Proportionality
DUP	38	35.2%	30.1%	+2	+5.1%
SF	31	28.7%	26.2%	+3	+2.5%
UUP	17	15.7%	14.9%	-1	+0.8%
SDLP	12	11.1%	15.2%	-4	-4.1%
AP	7	6.5%	5.2%	0	+1.3%
GP	1	0.93%	1.7%	0	-0.77%
OTH	1	0.93%	3.2%	0	-2.27%

As you can see, these results are less proportional than the actual electoral outcome. The DUP would have been over-represented by 5.1%, and Sinn Fein would have been over-represented by 2.5%. The hard-line parties would have won more seats than they actually received with choice voting. The moderate parties, the UUP and the SDLP, would have lost more seats with limited than with choice voting. The SDLP would have received four fewer seats, under-representing the supporters of this moderate party by 4.1%.

Proportional voting helped elect moderate party candidates who would not have won if a less proportional voting system were used. Moderates in Northern Ireland"s Legislative Assembly will play a crucial role in bridging the tensions between the two hard-liner parties, the DUP and Sinn Fein, in order to form a power-sharing government. Devolved home rule remains contingent upon the formation of a power sharing government. Thus the inclusion of more moderates is an important characteristic of Northern Ireland"s system of proportional voting.

See the electoral outcome district-by-district at http://news.bbc.co.uk/2/shared/vote2007/nielection/html/main.stm.

Barto is an intern at FairVote. He lives in Bucks County, Pennsylvania, and is a sophomore at the University of Pennsylvania.