(Dec 17): On the most important issue in the United Kingdom’s modern history – whether to leave the European Union or remain – the UK’s electoral system produced an absurd result. A majority of the UK public wants to remain in the EU, and actually voted accordingly in the parliamentary election on December 12. Yet the election produced a large majority for the Conservative Party, which backs a quick Brexit. The reason is as simple as it is troubling: the failure of the first-past-the-post electoral systems to translate public sentiment into reasonably representative outcomes.
In a first-past-the-post electoral system, each legislative seat goes to the candidate who wins the largest share of the vote, regardless of whether it is a majority. Thus, when majority opinion is divided among several parties, the minority view prevails with a minority of votes.
As a simple illustration, suppose that there are three parties: Remain-1, Remain-2, and Leave. Suppose that in every district, 66% of the public wants to remain and 34% wants to leave, with the remain voters divided evenly between the two remain parties. Remain-1 and Remain-2 each receive 33% of the vote in every district, while the Leave Party wins the district seat with 34%. If this result is replicated across all districts, the Leave Party wins 100% of the seats with 34% of the national vote. In a nationwide proportional-representation system, by contrast, the Remain parties would win 66% of the seats and would form the government.