The Center for Voting and Democracy: Factsheet
Modified At-Large Voting Systems for U.S. Local Elections
A voting system translates people's votes into seats in a legislative assembly. Many different voting systems exist. Because the same votes in different systems can produce different results, the selection of a voting system has a powerful impact on governance and fair representation.
Modified at-large voting systems are one-person, one-vote systems in which far more than 50% of voters elect candidates of their choice. To provide greater electoral fairness, candidates are elected at-large or in multi-member districts (constituencies electing more than one representative), but without using one of the "winner-take-all" methods common in the United States. Winner-take-all elections easily can allow 51% of voters to earn 100% of representation.
Nearly all democracies instead use versions of modified at-large systems. The following three systems are based on voting for candidates and currently used in some local elections in the United States. Choice voting is the system most likely to provide fairness both to minority and majority populations, promote competition and discourage negative campaigns.
In limited voting, voters either cast fewer votes than the number of seats or political parties nominate fewer candidates than there are seats. The greater the difference between the number of seats and the number of votes, the greater the opportunities for fair representation. Versions of limited voting are used in Washington, D.C., Philadelphia (PA), Hartford (CT) and many smaller jurisdictions. It has been used successfully to resolve several Voting Rights Act cases.
Example: In a race to elect five candidates, voters could be limited to two votes. Winning candidates are determined by a simple plurality (whichever five candidates get the most votes).
In cumulative voting, voters cast as many votes as there are seats. But unlike winner-take-all systems, voters are not limited to giving only one vote to a candidate. Instead, they can put multiple votes on one or more candidates. Voting rights scholar Lani Guinier has promoted cumulative voting as a colorblind means to provide fair minority representation.
Perhaps the simplest version of cumulative voting is to allow voters to vote for up to as many candidates as there are seats (as with winner-take-all voting), then allocate votes equally among the candidates selected by the voter. In a five seat race, voters selecting two candidates thus would provide each candidate with 2.5 votes.
Cumulative voting was used to elect the Illinois state legislature from 1870 to 1980. In recent years it has been used to resolve voting rights cases for city council elections in Amarillo (TX) and Peoria (IL), for county commission elections in Chilton County (AL) and for school board elections in Sisseton (SD) and more than fifty other jurisdictions; in most cases a member from the protected minority was elected following the implementation of cumulative voting. Cumulative voting in 1994 was imposed by a federal judge in a Maryland voting rights case.
Example: In a race to elect five candidates, voters cast one vote for five candidates, five votes for one candidate or a combination in between. Candidates win by a simple plurality of votes.
Choice voting (e.g, "single transferable vote" or "preference voting") is a form of limited voting in which voters maximize their one vote's effectiveness through ranking choices. Choice voting is very likely to provide fair results, can be used in both partisan and non-partisan elections and does not require primaries. It is recommended as the best system for local government elections.
To vote, voters simply rank candidates in order of preference, putting a "1" by their first choice, a "2" by their second choice and so on. Voters can rank as few or as many candidates as they wish, knowing that a lower choice will never count against the chances of a higher choice.
To determine winners, the number of votes necessary for a candidate to earn office is established based on a formula using the numbers of seats and ballots: one more than
1/(# of seats + 1). In a race to elect three seats, the winning threshold would be one vote more than 25% of the vote -- a total that would be mathemetically impossible for four candidates to reach.
After counting first choices, candidates with the winning threshold are elected. To maximize the number of voters who help elect someone, "surplus" ballots beyond the threshold are transferred to remaining candidates according to voters' next-choice preferences: in the most precise method, every ballot is transferred at an equally reduced value. After transferring surplus ballots until no remaining candidate has obtained the winning threshold, the candidate with the fewest votes is eliminated. All of his/her ballots are distributed among remaining candidates according to voters' next-choice preferences. This process continues until all seats are filled. Computer programs have been developed to conduct the count, although the ballot count often is done by hand.
Choice voting has been used for city council elections in Cambridge (MA) since 1941 and is used for Community School Board elections in New York and for national elections in Ireland and Australia. Cambridge's 13% African-American community has helped elect a black candidate in every election since the 1950s; choice voting in other cities -- like New York in the era of Mayor Fiorello La Guardia -- also resulted in fair racial, ethnic and partisan representation.
Example: The chart below illustrates choice voting in a partisan race with 6 candidates running for 3 seats: Jones, Brown and Jackson are Democrats; Charles, Murphy and Stevens are Republicans. With 1000 voters, the threshold of votes needed to win election is 251: (1000/4) + 1.
Note that Democrats Brown and Jones and Republican Charles win, with over 75% of voters helping directly to elect a candidate. Having won 60% of first choice votes, Democrats almost certainly would have won three seats with a winner-take-all, at-large system. (They also would have won three seats with a limited vote system -- and likely with cumulative voting -- because of "split votes" among the Republicans.) Despite greater initial support, Murphy loses to Charles because Murphy is a polarizing candidate who gains few transfer votes. Finally, 45 of 345 voters who help elect Brown in the fourth count chose not to rank Charles and Murphy, which "exhausts" their ballots.
|1st Count||2nd Count||3rd Count||4th Count||5th Count|
||Jones' surplus transferred||Smith's votes transferred||Jackson's votes transferred||Brown's votes transferred|
|Brown (D)||175||+10 = 185||+ 10 = 195||+150 = 345||- 94 = 251|
|Jones (D)||270||-19 = 251||-||-||-|
|Jackson (D)||155||+ 6 = 161||+ 6 = 167||- 167 = 0||-|
|Charles (R)||130||+ 2 = 132||+ 75 = 207||+ 14 = 221||+ 44 = 265|
|Murphy (R)||150||+ 0 = 150||+ 30 = 180||+ 3 = 183||+ 5 = 188|
|Smith (R)||120||+ 1 = 121||-121 = 0||-||-|
|Exhausted||-||-||-||-||+ 45 = 45|