How people elect parliaments
The lower house of Éire’s bicameral Oireachtas (Legislature) is the Dáil Éireann (literally Assembly of Ireland, but also translatable as National Assembly), an assembly currently of 166 members.
Teachtai Dála (members) are directly elected in 43 multi-member divisions (termed ‘constituencies’) by the single transferable vote (STV) method.
Éire is one of only two nations in the world – the other being Malta – to elect its lower house by this method. The STV method, used in Ireland since 1921, was entrenched in the national constitution in 1937 and two referendum attempts (in 1959 and 1968) to replace it with plurality voting were rejected by the electorate.
The Constitution also sets the minimum number of seats in a division at three, and requires that the overall ratio of members in each division to population must fall between 1:20,000 and 1:30,000. Legislative provisions adopted in 2011 provide that the number of members must be between 153 and 160, meaning that the 2016 election will see a fall in the previous number of members.
Constituency boundaries are reviewed by an independent commission at least every 12 years to reflect changes in population distribution and to minimise malapportionment; the most recent revision applies from the 2016 election.
Each division is allocated either 3, 4 or 5 seats, and specific seat allocations to divisions are revised for each election. At the 2016 elections there will be 13 3-member divisions, 16 4-member divisions and 11 5-member divisions, totalling 158 seats.
If at an election the sitting presiding officer of the Dáil (the Ceann Comhairle) does not retire, he or she is deemed to have been re-elected in their constituency, and that constituency elects one fewer member than its initial allocation of seats.
Candidate names are listed on ballot papers in alphabetical order in a single column.
By-elections are held using preferential voting, which often causes the vacant seat to change hands between parties.
Terms are up to five years.
Preview of the Éire election of April 2016 (January 2016)
Three Irish Just So Stories (January 2016)
Inequality in the effective influence of voters caused by variations in Dáil division enrolments is low in comparison with other nations due to the use of STV. The standard deviation of variations compared to the mean enrolment was ….
[nomination openness – party configurations]
[summary of results]
Inequality in the effective influence of voters caused by variations in division turnouts (formal votes) is low in comparison with other nations due to the use of STV. The standard deviation of variations compared to the mean formal vote was … .
[inequality by margins]
2002 – 2007 – 2011 – 2016 – 2017
[data source – data completeness – anomalous contests]
[Datasets are not yet published]