Highest averages method
Rule for proportional allocation / From Wikipedia, the free encyclopedia
In mathematics, economics, and social choice theory, the highest averages methods, also called the divisor methods,[1] are a family of apportionment methods. These methods seek to fairly divide a legislature between several groups, such as political parties or states.[1][2] More generally, divisor methods give a way to round shares of a total, e.g. percentage points (which must add up to 100). The two names for these methods—highest averages and divisors—reflect two different ways of thinking about them, and their two independent inventions. However, both procedures are equivalent and give the same answer.[1]
Divisor methods aim to treat voters equally by ensuring every legislator represents an equal number of voters, as nearly as practicable, by iteratively assigning additional representatives to whichever party is most underrepresented.[3]: 30 In doing so, the method maintains proportional representation, i.e. a party with twice as many votes should win twice as many seats.[3]: 30