Representation by population

Representation by population

This is the preferred (and very common) method for democratic countries, where elected representatives will be chosen by similarly-sized groups of voters defined by single-member districts. This is expressed commonly by the term "one person, one vote" in the US, and is commonly used to apply to equality between the many single-member districts that divide the country. The votes-to-seat ratio is commonly based on local census records of population. However even where districts are very equal in size, under the first-past-the-post electoral system, elected members receive wide variation of votes cast, due to varying number of voters within the population, varying voter turn-out rate, and varying percentage of votes cast that are necessary to win a plurality, from district to district.