This series is part of the Politics and the Election series
The Kemeny-Young method is a voting system that uses preferential ballots, pairwise comparison counts, and sequence scores to identify the most popular choice, and also identify the second-most popular choice, the third-most popular choice, and so on down to the least-popular choice. This is a Condorcet method because if there is a Condorcet winner it is always the most popular choice.
The system was developed

Single member

• Plurality (first-past-the-post)
  Two-round system
  Exhaustive ballot
  Preferential systems
  
  
  
  • Satisfy Condorcet criterion
    
    
    
    • Condorcet method
      Copeland's method
      Kemeny-Young method
      Minimax Condorcet
      Nanson's method
      Ranked Pairs
      Schulze method
      Runoff voting
      
      
      
      • Bucklin voting
        Coombs' method
        Instant-runoff
        Non-rank methods
        
        
        
        • Approval voting
          Range voting
          Multi-member
          
          
          
          • Proportional representation
            
            
            
            • Cumulative voting
              Mixed-member
              Party-list (Open and Closed)
              
              
              
              • D'Hondt method
                Highest averages method
                Largest remainder method
                Sainte-Laguë method
                Single transferable vote
                Semi-proportional representation
                
                
                
                • Additional Member System
                  
                  
                  
                  • Parallel voting
                    Cumulative voting
                    Single non-transferable vote
                    Non-proportional multi-member representation
                    
                    
                    
                    • Bloc voting
                      Limited voting
                      Random Selection
                      
                      
                      
                      • Sortition Characteristics
                        Calculating all sequence scores requires time proportional to N!, where N is the number of choices. This is significantly more time than required for most other voting methods. This calculation time is superpolynomial in the number of choices, so it does not meet the polynomial runtime criteria.
                        Not every sequence score needs to be calculated to identify the Kemeny ranking. Fast calculation methods, including those based on linear programming, allow the computation of the Kemeny ranking for as many as 40 choices.