Approval voting

Approval voting
Name	Approval voting
Type	single-winner electoral system
Inventor	Multiple independent proposals
First use	20th century implementations
Used by	Organizations, municipalities, professional societies

Approval voting is an electoral method in which voters may select (approve) any number of candidates, and the candidate with the most approvals wins. It has been discussed and promoted in contexts involving Walter Wheeler, Herschel L. Collins, Brams, Fishburn, and advocates associated with Center for Election Science, FairVote, and various academic journals. Debates about its adoption have involved organizations such as the American Bar Association, Society for Industrial and Applied Mathematics, and municipal governments in places like Fargo, North Dakota, St. Louis, Missouri, and Nascent adoption efforts.

Overview

Approval voting permits each elector to mark every candidate they find acceptable; no ranking or scoring beyond approval is recorded. Prominent theorists such as Steven Brams, Peter C. Fishburn, Robert J. Weber, Guy Ottewell and commentators from institutions like Carnegie Mellon University, Harvard University, and Princeton University have analyzed its normative implications. Practical discussions often reference comparative systems including First-past-the-post, Instant-runoff voting, Score voting, Range voting, and Condorcet methods in evaluating representativeness, simplicity, and susceptibility to strategic behavior.

Voting method and ballot design

Ballots in approval systems are typically simple check-box or mark-the-candidate forms enabling multiple selections; implementations in organizational elections have used paper, optical-scan, and electronic interfaces designed by vendors such as Election Systems & Software and research projects at Massachusetts Institute of Technology. Variants include single-winner and multi-winner applications, applied to contexts like board elections in the American Mathematical Society and committee selection in IEEE. Ballot instructions and user interface choices often draw on guidelines from National Association of Secretaries of State and election administration literature published by Brennan Center for Justice and Bipartisan Policy Center.

Advantages and criticisms

Advocates point to advantages highlighted in analyses by Brams, Fishburn, Douglas R. Hofstadter-adjacent commentators, and comparative studies at Princeton University: simplicity, resistance to the spoiler effect documented in disputes like Nader 2000 controversy, and improved expression of voter acceptability relative to plurality voting used in elections such as those in United Kingdom and United States presidential elections. Critics, including scholars affiliated with Clemson University, University of Oxford, and commentators in The Economist, raise concerns about strategic incentives, lack of intensity expression compared to range voting and potential ballot exhaustion analogues. Debates often reference empirical reviews by Nolan McCarty and case analyses from University of Minnesota and University of Maryland.

Strategic voting and behavior

Strategic dynamics under approval have been explored by game theorists at Stanford University, Rutgers University, and Yale University, comparing equilibria to those in plurality runoff and instant-runoff scenarios. Concepts such as bullet voting, compromise voting, and tactical approvals are discussed in research by Donald Saari, Myerson, and Zhao. Laboratory experiments and field studies by teams at University of Oxford, California Institute of Technology, and University of Pennsylvania examine voter behavior, while elections in Fargo, North Dakota and internal American Political Science Association contests provide empirical evidence of strategic patterns.

Mathematical properties and criteria

Approval voting satisfies some voting-theoretic criteria and fails others; formal analyses by Arrow, Gibbard, Satterthwaite, Tideman, and Fishburn place it within social choice theory. It is monotonic in relevant respects and can elect a Condorcet winner in many profiles but does not always meet the laterno-Condorcet-consistent standards. Researchers from London School of Economics, University of Cambridge, and ETH Zurich have published proofs related to proportional extensions (approval-based apportionment) and axiomatic properties such as participation, consistency, and clone independence, connecting to algorithms used in proportional representation literature and apportionment laws like those discussed in United States Congressional apportionment debates.

Historical development and adoption

Early conceptual precursors appear in 19th- and 20th-century electoral reform literature; modern formalizations emerged in late 20th-century work by scholars including Brams and Fishburn, with advocacy groups such as Approval Voting, Inc. and research centers at Carnegie Mellon University promoting adoption. Municipal experiments include referenda and council decisions in Fargo, North Dakota, St. Louis, Missouri, and pilot efforts in parts of Poland and Switzerland; professional societies adopting approval-style ballots include Mathematical Association of America, American Statistical Association, and IEEE. Legislative and ballot initiatives have been debated in state legislatures and at forums sponsored by National Conference of State Legislatures and League of Cities.

Practical implementations and case studies

Notable case studies include the adoption and subsequent usage analyses in Fargo, North Dakota mayoral and city commission elections, internal elections in Society for Industrial and Applied Mathematics and American Mathematical Society, and polls run by organizations such as The Economist and Pew Research Center using approval formats. Implementation issues—ballot design, voter education, tallying software, and auditability—have been addressed in reports by Brennan Center for Justice, vendors like Dominion Voting Systems, and technical teams at MIT Election Data and Science Lab. Comparative outcome studies relate approval results to historical contests such as 2000 United States presidential election hypotheticals and alternative-method analyses of races in United Kingdom general elections and Canadian federal elections.

Category:Electoral systems