Nicaragua has a unicameral National Assembly (Asamblea Nacional) elected largely by proportional representation. However, the country has repeatedly tweaked the specifics of the system’s operation and more recently added provisions for extra seats. Lists have remained closed despite other alterations to the system; candidates may not run in more that one constituency.

NICARAGUA 1 (1984)
Nicaragua utilized this two-tier system for the 1984 elections. In each of the 10 electoral constituencies, parties had to receive a Hare quota–valid votes divided by mandates in the constituency–to qualify for seats. Parties received initially as many seats as they had won multiples of the Hare quota.

Any votes mandates not allocated in the constituencies for full Hare quotas were gathered together at the national level and allocated using the largest remainder system with a Hare quota based on votes not used in the constituencies towards full Hare quota seats. Seats first went to parties with full Hare quotas–valid unused votes divided by unallocated mandates–with any seats left allocated based on remainder votes (i.e. in descending order of votes not used already towards a full Hare quota and a seat).

NICARAGUA 2 (1990)
Nicaragua utilized this single-tier system with 9 electoral constituencies for the 1990 elections. In the 6 constituencies with 9 or more mandates, the largest remainder system with a Hare quota was used to allocate seats. In the 2 constituencies with 2 or 3 members, seats were also allocated by the largest remainder system but according to the Hagenbach-Bischoff quota rather than the Hare quota. While the Hare quota equals valid votes divided by the number mandates, the Hagenbach-Bischoff quota equals valid votes divided by the number of mandates plus one. (Unlike in the previous electoral system, remainder seats and votes were not gathered together at the national level but allocated within constituencies by largest remainders).

In the sole single-member constituency, the deputy was chosen by plurality. That is, the candidate with the most votes won election.

NICARAGUA 3 (1996)
This system was used for the 1996 elections. Voters possessed 2 votes–1 for departmental deputies and 1 for national deputies. The 20 national mandates were allocated based on the national deputy vote utilizing the largest remainder system with a Hare quota.

The allocation of the 70 departmental mandates resembled the electoral system utilized in 1984. Departmental seats were first allocated for full Hare quotas (based on the departmental deputy vote) within the 12 constituencies with remainder votes and mandates gathered together at the national level and allocated according to the largest remainder system with a Hare quota.

Michael Krennerich (2005: 485) describes the allocation of seats back to constituencies as follows:

First, a given seat percentage was allocated to each constituency according to a decreasing order of valid votes obtained by each party; next, in each constituency the seats were distributed among the parties in a decreasing order of the votes obtained by each constituency in the previous stage. The number of remaining seats allotted to one constituency could never surpass the number of deputies to be elected in it. The redundant seats were transferred to the next constituencies in decreasing order of the vote. The process was repeated until all the remaining seats were distributed among the constituencies.

Additionally, all losing presidential candidates who received at least 1% of the vote also gained seats in the National Assembly.

NICARAGUA 4 (2001-)
Voters still possess 2 votes–1 for departmental deputies and 1 for national deputies. The number of deputies elected from the national constituency remains 20. The other 70 deputies are elected from 17 constituencies that correspond to the 15 departments and 2 autonomous regions.

The Electoral Law apportions a specific number of mandates to each department or autonomous region (i.e. no electoral formula and the number of mandates doesn’t change unless the law is altered). Here is the apportionment:

The national constituency seats are allocated first to parties for full multiples of the Hare quota–the number of valid votes divided by the number of national constituency mandates (20). Any remaining national constituency seats are allocated by the d’Hondt highest average method of proportional representation.

In departmental constituencies with 3 or more mandates, seats are likewise allocated to parties first for full multiples of the departmental Hare quota (i.e. valid votes divided by the number of mandates in the departmental constituency) and then by the d’Hondt highest average method if any seats remain.

However, in constituencies with 1 or 2 seats, seats are allocated first to parties for full multiples of the Hagenbach-Bischoff quota–valid votes divided by the number of mandates in the constituency plus one–and then by the d’Hondt method if any seats remain. In the one seat constituency, the result is the same as plurality elections (i.e. the party with the most votes obtains the seat).

The following table shows the allocation of Matagalpa’s 6 departmental seats in 2011:

As Matagalpa has more than 2 seats, the Hare rather than the Hagenbach-Bischoff quota to allocate seats. Only the FSLN and PLI had at least one full Hare quota and received seats–3 for FSLN and 2 for PLI. One seats remained to be allocated by the d’Hondt method. The D’Hondt quota equals votes divided by the number of seats already gained by the party plus one. For example, the FSLN d’Hondt quota equaled 140,413/(3 + 1). As the FSLN quota was the highest, it received the final seat.

The law governing the allocation of additional seats has been changed so that the outgoing president and second-place presidential candidate are now the recipients of seats in the National Assembly. So the total number of seats is 92. Someone else can take up the seat designated for the president who is reelected.

Sources: Ley Electoral, Ley No. 331, Aprobada el 19 de Enero del 2000, Publicada en la Gaceta No.16 del 24 de Enero del 2000; Michael Krennerich, “Nicaragua” in Dieter Nohlen, ed. Elections in the Americas, Vol. 1 (New York: Oxford University Press 2005), 479-510.