The Imperiali quota is a formula used to calculate the minimum number, or

quota Quota may refer to: Economics * Import quota, a trade restriction on the quantity of goods imported into a country * Market Sharing Quota, an economic system used in Canadian agriculture * Milk quota, a quota on milk production in Europe * Indi ...

, of votes required to capture a seat in some forms of

single transferable vote Single transferable vote (STV) is a multi-winner electoral system in which voters cast a single vote in the form of a ranked-choice ballot. Voters have the option to rank candidates, and their vote may be transferred according to alternate p ...

largest remainder method The largest remainder method (also known as Hare–Niemeyer method, Hamilton method or as Vinton's method) is one way of allocating seats proportionally for representative assemblies with party list voting systems. It contrasts with various h ...

party-list proportional representation Party-list proportional representation (list-PR) is a subset of proportional representation electoral systems in which multiple candidates are elected (e.g., elections to parliament) through their position on an electoral list. They can also be us ...

voting systems An electoral system or voting system is a set of rules that determine how elections and referendums are conducted and how their results are determined. Electoral systems are used in politics to elect governments, while non-political elections ma ...

. It is distinct from the

Imperiali method A highest-averages method, also called a divisor method, is a class of methods for allocating seats in a parliament among agents such as political parties or federal states. A divisor method is an iterative method: at each iteration, the number ...

, a type of highest average method. It is named after Belgian senator Pierre Imperiali. The

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

and

Ecuador Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...

are among the few countries that currently use this allocation system, while

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical re ...

used it for its

Chamber of Deputies The chamber of deputies is the lower house in many bicameral legislatures and the sole house in some unicameral legislatures. Description Historically, French Chamber of Deputies was the lower house of the French Parliament during the Bourbon R ...

from 1946 to 1993. If many party lists poll just over the Imperiali quota, it is possible for this method to distribute more seats than there are vacancies to fill (this is not possible with the Hare or Droop quotas). If this occurs, the result needs to be recalculated with a higher quota (usually the Droop quota). If it does not happen, Imperiali usually distributes seats in a similar fashion to the

D'Hondt method The D'Hondt method, also called the Jefferson method or the greatest divisors method, is a method for allocating seats in parliaments among federal states, or in party-list proportional representation systems. It belongs to the class of highest- ...

. The imperiali quota should not be confused with the highest average method, which is also called Imperiali.

Formula

The Imperiali quota may be given as: :

\frac

*Total votes = the total valid poll; that is, the number of valid (unspoilt) votes cast in an election. *Total seats = the total number of seats to be filled in the election.

An example of use in STV

To see how the Imperiali quota works in an STV election imagine an election in which there are two seats to be filled and three candidates: Andrea, Carter and Brad. There are 100 voters as follows: There are 100 voters and 2 seats. The Imperiali quota is therefore: :

\frac = 25

To begin the count the first preferences cast for each candidate are tallied and are as follows: *Andrea: 65 *Carter: 15 *Brad: 20 Andrea has more than 25 votes. She therefore has reached the quota and is declared elected. She has 40 votes more than the quota so these votes are transferred to Carter, as specified on the ballots. The tallies therefore become: *Carter: 55 *Brad: 20 Carter has now reached the quota so he is declared elected. The winners are therefore Andrea and Carter.

References

{{DEFAULTSORT:Imperiali Quota Electoral system quotas