Imperiali quota

The Imperiali quota is a formula used to calculate the minimum number, or quota, of votes required to capture a seat in some forms of single transferable vote or largest remainder method party-list proportional representation voting systems. Ecuador is among the few countries that uses this allocation system.

It is :$frac\{mbox\{total\}\; ;\; mbox\{votes\{mbox\{total\}\; ;\; mbox\{seats\}+2\}.$

Typically its effect is kinder to larger parties than using the Droop quota or Hare quota, and will not produce a proportional result, even when this is possible. It produces smaller numerical quotas, which creates a risk that more candidates will be elected with full quotas than there are seats. Indeed, in a two list election, or in an STV election where all votes transfer, it is inevitable that the wrong number of candidates will be elected, requiring some further adjustment. This flaw means that it is rarely used.